Ministry of Education and Science of the Samara Region

State budgetary educational institution

secondary vocational education

"Provincial College of Syzran"

Technical profile

Toolkit

TECHNOLOGICAL PIPELINES

PM 01 Operation of technological

equipment.

PM 05 Performance of work by profession

Process plant operator

Syzran.

2015 year

Methodological manual on the topics PM 01 "Operation of technological equipment,

PM 05 Performance of work by profession Operator of technological installationsMDK 05.02. Repair of technological equipment.

(name of the methodological development)

Brief description of the Methodological Guide

This methodological guide presents types of process pipelines, operating rules, maintenance requirements, preparing them for repair and testing. It is intended for students of the SPO "GK of Syzran" in the specialty 240134.51 Oil and gas processing during training in the professional module PM 01. Operation of technological equipment and PM 05 performing work by profession Operator of technological installations.

The methodological manual will allow students to form knowledge and practical skills in the operation of equipment of oil refineries.

Compiled by: Pirogova Galina Nikolaevna- teacher of special discipline.

APPROVED AT THE PCC MEETING

Oil and gas processing. Ecology

(name of the commission)

Chairman _____________________ V.V. Mokeeva

FULL NAME

Minutes No. __________ dated "____" __________ 2015

Methodist of technical profile _______________ L.N. Barabanova

FULL NAME.

"APPROVED"

Deputy Director for UPR

Head of the technical profile __________________ V.V. Kolosov

Process pipelines

1. Learning goal

The purpose of studying the topic "Technological pipelines" is to teach students the classification, types of technological pipelines, operating rules, maintenance requirements, preparing them for repair and testing.

1.1. Concept, basic terms

Definition of technological pipelines, their classification. Layout of pipelines. Elements of pipelines. Division of pipeline fittings into: shut-off, control, safety. Types of connection of fittings to pipelines. Structural elements of reinforcement. Operation and repair of technological pipelines.

Pipeline- a structure made of pipes, pipeline parts, fittings, tightly connected to each other, intended for the transportation of gaseous and liquid products.

Technological refers to the pipelines of industrial enterprises, through which raw materials, semi-finished products, finished products, steam, water, fuel, reagents and other materials that ensure the execution of the technological process and the operation of equipment are transported, waste reagents, gases, various intermediate products obtained or used in the technological process, waste production.

Flanged connection- a fixed detachable connection of the pipeline, the tightness of which is ensured by compressing the sealing surfaces directly with each other or through gaskets of a softer material located between them, compressed by fasteners.

Welded connection- a fixed connection of the pipeline, the tightness of which is ensured using welding.

Diversion- shaped part of the pipeline, providing a change in the direction of the flow of the transported substance.

Tee- shaped part of the pipeline for merging or dividing flows of the transported substance at an angle of 90 ° C.

Union- a part intended for connecting fittings, instrumentation, etc. to the pipeline.

Transition- shaped part of the pipeline, designed to expand or narrow the flow of the transported substance.

Pipeline section- a part of a process pipeline made of one material, through which a substance is transported at constant pressure and temperature.

Pipeline accessories- devices installed on pipelines and providing control of the flows of working media by changing the flow area.

Conditional passage Du- the nominal internal diameter of the pipeline, providing the required throughput.

Nominal pressure PN- the smallest overpressure at a substance or ambient temperature of 20 0 C, at which the long-term operation of valves and pipeline parts with specified dimensions, justified by strength calculations, with selected materials and their strength characteristics corresponding to this temperature, is permissible.

Working pressure Pp- the highest safe overpressure at which the specified operating mode of valves and pipeline parts is ensured.

Test pressure Ppr- excess pressure, at which a hydraulic test of fittings and pipeline parts for strength and density with water at a temperature of not less than +5 0 С and not more than +40 0 С should be carried out.

2. Content of the educational element

To teach students the theory and practical implementation of work on the operation, revision, repair of technological pipelines and pipeline fittings.

2.1. General concepts

Pipeline- a device designed for the transportation of gaseous, liquid and bulk substances.

Depending on the medium being transported, the names water pipe, steam pipe, air pipe, oil pipe, gas pipeline, oil pipeline, product pipeline, etc. are used.

The design of the pipeline must be reliable, ensure safety during operation and provide for the possibility of its complete emptying, cleaning, flushing, purging, external and internal inspection and repair, removing air from it during hydraulic testing and water after it.

The main characteristic of any pipeline is its diameter, which determines its flow area required to transport a given amount of a substance under operating operating parameters (pressure, temperature, speed).

All technological pipelines with a pressure of up to 100 kgf / cm 2 inclusively, depending on the hazard class of the transported substance (explosion and fire hazard and harmfulness), are divided into groups (A, B, C) and, depending on the operating parameters of the environment (pressure and temperature), into five categories (I, II, III .IV, V).

Process pipelines consist of tightly interconnected straight sections, pipeline parts (bends, transitions, tees, flanges), gaskets and seals, supports and hangers, fasteners (bolts, studs, nuts, washers), shutoff and control valves, control and measuring instruments, automation equipment, as well as thermal and anti-corrosion insulation.

Depending on the location at an industrial facility, process pipelines are subdivided into intrashop, connecting units, machines and apparatus of the process units of the workshop, and inter-workshop, connecting the process units of different workshops. Intrashop pipelines are called piping if they are installed directly within individual devices, pumps, compressors, tanks, etc. and connect them.

In-shop pipelines have a complex configuration, a large number of parts, fittings and welded joints. For every 100 m of the length of such pipelines, there are up to 80-120 welded joints. The mass of parts, including fittings, in such pipelines reaches 37% of the total mass of the pipeline.

Inter-workshop pipelines, on the contrary, are characterized by rather straight sections (up to several hundred meters long), a relatively small number of parts, fittings and welds. The total weight of parts in inter-shop pipelines (including fittings) is 5%, and U-shaped expansion joints are about 7%

Process pipelines are considered cold if they operate in an environment with an operating temperature t p  50 0 C, and hot if the temperature of the working environment> 50 0 C.

Depending on the nominal pressure of the medium, pipelines are subdivided into vacuum, operating at an absolute pressure of the medium below 0.1 MPa (abs) or from 0 to 1.5 MPa (g), medium pressure, operating at a medium pressure of 1.5 to 10 MPA ( hut). Non-pressure pipelines are those that operate without excess pressure ("gravity").

Connections in pipelines for transporting liquefied gases should be carried out mainly by welding. Flanged connections can be used in the places where the valves are installed in order to connect them to the pipeline. They can also be used in pipelines that require periodic disassembly in order to clean or replace individual sections. Welding is the most expedient and reliable method of joining steel pipelines and fittings to the pipeline. It is widely used in pipeline systems for various purposes, but in many cases flange connections are also used, which have their own advantages and disadvantages, like detachable connections. In pipelines with small nominal diameters, threaded connections are often used.

The location of pipelines should ensure:

safety and reliability of operation within the standard period;

the possibility of direct observation of the technical condition;

the ability to perform all types of work on the control, heat treatment of welded seams and testing;

insulation and protection of pipelines from corrosion, secondary manifestations of lightning and static electricity;

preventing the formation of ice and other plugs in the pipeline;

exclusion of sagging and the formation of stagnant zones.

According to the method of laying pipes, pipelines or their sections are divided into the following:

underground- pipes are laid in a trench underground;

terrestrial- pipes are laid on the ground;

overground- pipes are laid above the ground on racks, supports or using the pipe itself as a supporting structure;

underwater- are constructed at crossings through water

obstacles (rivers, lakes, etc.), as well as when developing

ke offshore fields.

Questions to Consider:

What is the working pressure?

What requirements should the pipeline design meet?

How are technological pipelines divided depending on their location at an industrial facility?

Which process lines are considered cold?

What process pipelines are internal?

What pipes are used to transport fire and explosive media?

Where is it allowed to use flanged joints in pipelines for transporting gases?

2.2. Pipeline accessories

Pipeline fittings installed on pipelines or equipment are designed to shut off, distribute, control, mix or discharge the transported products.

By the nature of the functions performed, the valves are divided into classes: control, safety, shut-off and different.

Shut-off valves are designed to shut off the flow of the transported product (taps, valves, gate valves and rotary gates).

Regulatory- to regulate product parameters by changing its flow rate (control valves and valves, direct-acting regulators, mixing valves).

Safety- to protect installations, apparatuses, tanks and pipelines from unacceptable pressure increase (safety, bypass and non-return valves, as well as bursting discs).

According to the principle of operation, the valves can be autonomous (or direct acting) and controlled.

An autonomous valve is a valve, the working cycle of which is performed by a working medium without any extraneous energy sources (direct-acting pressure regulators, condensate traps, gas traps).

A controlled valve is called a valve whose operating cycle is performed according to the appropriate commands at the moments determined by the operating conditions or devices.

According to the control method, controlled valves are subdivided into manually operated valves (local control), driven valves (motor), and remote controlled valves (at a distance).

Hand-operated valves are operated by rotating a handwheel or handle mounted on a spindle or spindle nut directly or via a gearbox.

The drive armature is equipped with a drive installed directly on it. The drive can be electric, electromagnetic, with a diaphragm or with an electric actuator, pneumatic, pneumatic bellows, hydraulic and pneumohydraulic. The remote control valve is operated from the actuator.

Depending on the design of the connecting pipes, the fittings are divided into flanged, coupling, pinned and welded. Coupling and pinned cast iron fittings are recommended only for pipelines with a nominal bore of not more than 50 mm, transporting non-combustible neutral media. Coupling and trunnion steel fittings can be used on pipelines for all media with a nominal diameter of no more than 40 mm.

Flanged and welded fittings are allowed to be used for all categories of pipelines.

The applied pipeline fittings must comply with the requirements of GOST 12.2.063 “Industrial pipeline fittings. General safety requirements ". The main types of connection of pipeline fittings to the pipeline are shown in Figure 1.

The pipeline fittings are supplied from the manufacturing plants in complete sets with counter flanges, gaskets and fasteners.

The choice of the type of sealing surface of the flanges for connecting the pipelines depends on the conveyed medium and pressure.

For pipelines transporting substances of groups A and B of technological objects of the I category of explosion hazard, it is not allowed to use flange connections with a smooth sealing surface, except for the cases of using spiral-wound gaskets.

a
-flanged (cast flanges with a connecting ledge and flat gasket);

b - flanged (steel butt-welded flanges with a protrusion-cavity seal with a flat gasket);

c - flanged (cast flanges with a thorn-groove seal

with flat gasket);

d - flanged (steel flat welded flanges and flat gasket);

d - flanged (cast flanges with lens gasket);

e - flanged (cast steel flanges with oval section gasket);

g - coupling;

h - tsapkovoe.

According to the method of shutting off the medium flow, the fittings are subdivided into the following - a gate valve in the form of a disk, plate or wedge (moves reciprocally in its plane, perpendicular to the axis of the medium flow (Fig. 2).

shut-off or regulatory body;

frame;

housing sealing surfaces.

Gate valves by gate type are divided into wedge and parallel. The gate valve (fig. 2) has a gate valve in which the sealing surfaces are at an angle to each other. They can be with a solid wedge (rigid or elastic) and two-disc. The parallel gate valve can be a gate valve (single-disc or sheet) and double-disc with a wedge spacer.

Questions to Consider:

What classes are pipe fittings divided into according to the nature of their functions?

The purpose of the safety fittings.

How controlled valves are subdivided by methods

management?

What are the ways to block the flow of the medium?

2.3. Structural elements of reinforcement

Various reinforcement designs contain parts and assemblies that have a general purpose and the same names (Fig. 8). These elements include the following:

To
hull- a part replacing a pipe segment with a length equal to the distance between the ends of the attached flanges or branch pipes to be welded to the pipeline. The body together with the lid forms a hermetically sealed cavity from the external environment, inside which the shutter moves;

1 - case; 2 - shutter; 3 - spindle; 4 - a sealing gasket; 5 - push sleeve; 6 - flywheel; 7 - stuffing box; 8 - an annular gasket; 9 - top cover; 10 - running nut; 11 - saddle.

gate- the movable part of the working body - a part or a structurally combined group of parts intended for hermetic separation of two sections of the pipeline by blocking the passage opening in the flowing part of the body;

For a tight shutoff of the flow, a seat is provided in the body, equipped with an O-ring. It can be formed by the metal of the body, by overlaying corrosion-resistant steel, brass, or by installing an O-ring made of corrosion-resistant steel, brass, nickel alloy, plastic by pressing, threaded, caulking and other fastening methods. The shutter in the valves is a valve disc (for small sizes, it is called a spool), in valves, a wedge or disc, or two discs at the same time, in valves, a plug in the form of a cone, cylinder or ball.

lid- a part used to seal the hole in the body through which the shutter is installed. In the controlled valve, the cover has a hole for the spindle;

spindle- a part, which is a rod, usually having a trapezoidal thread, with the help of which the shutter is controlled. A spindle that does not have a thread is called a stem.

The running nut also has a trapezoidal thread and forms a threaded pair with the spindle for moving the valve and setting it to the required extreme or intermediate position (self-locking thread).

stuffing box- a device designed to seal the movable mating of the cover with the spindle;

flywheel- a part (usually a casting) in the form of a rim with a hub connected to the rim by spokes. Serves for manual valve control to transfer torque generated by hand to the valve stem or spindle nut. The small size flywheel is manufactured in the form of a solid disc.

2.4. Supervision of pipelines during operation.

2.4.1. Reliable trouble-free operation of the pipeline and the safety of its operation should be ensured by constant monitoring of the condition of the pipeline and its parts, timely repairs in the amount determined during inspection and revision, and updating all pipeline elements as the metal is worn out and structurally changed.

Fig. 4.

2.4.2. By order of the enterprise, in each workshop (at each installation) a person responsible for the safe operation of pipelines from among the engineers and technicians serving these pipelines must be appointed.

2.4.3. Process pipelines, depending on the properties of the transported medium, are divided into three main groups A, B, C, and depending on the operating parameters of the medium (pressure and temperature) into five categories. If the required combination of parameters is absent in the table, the parameter is used, according to which the pipeline is assigned to a higher category (Appendix N 3).

2.4.4. For technological pipelines of categories I, II and III, as well as for pipelines of all categories, transporting substances with a corrosion rate of more than 0.5 mm / year, the head of the installation must draw up a passport of the established form (Appendix No. 2).

List of documents attached to the passport:

pipeline diagram indicating the nominal bore, initial and rejected thickness of pipeline elements, locations of fittings, flanges, plugs and other parts installed on the pipeline, places of drain, purge and drainage devices, welded joints (Appendix No. 3);

the certificate of inspection and rejection of pipelines (Appendix N 4);

certificate of the quality of pipeline repair.

For the rest of the pipelines at each installation, it is necessary to keep an operational log, in which the dates of the audits carried out and data on the repairs of these pipelines should be recorded (Appendix No. 5).

2.4.5. For each installation, the person responsible for the safe operation of pipelines must draw up a list of responsible technological pipelines, made in two copies: one is kept by the person responsible for the safe operation of pipelines, the other - in the department of technical supervision (Appendix No. 6) ...

2.4.6 During the operation of pipelines, one of the main duties of the maintenance personnel is constant and careful monitoring of the condition of the outer surface of pipelines and their parts: welds, flanged joints, including fasteners, fittings, insulation, drainage devices, expansion joints, supporting structures, etc. .P. The results of inspections should be recorded in the logbook at least once per shift.

Fig. 5.

2.4.7. Supervision over the correct operation of pipelines is carried out on a daily basis by the facility's engineers and technicians, periodically by the technical supervision service together with the person responsible for the safe operation of pipelines, at least once every 12 months.

Questions to Consider:

How are t / wires classified depending on the operating parameters and properties of the transported medium?

For which technological t / wires do you need to get passports of the established form?

On which technological t / wires it is necessary to keep an operating log of the established form?

2.5. Control methods

2.5.1. The main method of monitoring the reliable and safe operation of process pipelines is periodic audits, which are carried out by the technical supervision service together with mechanics and plant managers. The results of the audit serve as the basis for assessing the state of the pipeline and the possibility of its further operation.

The timing of the audit of technological pipelines is indicated in the projects, if they are absent, they are set by the OTN depending on the rate of their corrosion and erosion wear, operating experience, the results of the previous external inspection, revision. The timing should ensure safe, trouble-free operation of the pipeline in the period between revisions and should not be less frequent than those specified in Appendix 7.

During the audit, special attention should be paid to areas operating in particularly difficult conditions, where the maximum pipeline wear is most likely due to corrosion, erosion, vibration and other reasons.

These include areas where the direction of flow changes (elbows, tees, tie-ins, drainage devices, as well as pipelines in front of and after fittings) and where moisture and corrosion-causing substances may accumulate (dead-end and temporarily inoperative areas).

2.5.2. Conduct an external inspection of the pipeline.

External inspection of pipelines laid in an open way can be carried out without removing the insulation. However, if the condition of the walls or welds of the pipelines is in doubt, part or complete removal of the insulation must be carried out at the direction of an employee of the technical supervision department.

If during an external examination leaks in the detachable joints are found, the pressure in the pipeline should be reduced to atmospheric, the temperature of hot pipelines - to +60 ° C, and the defects should be eliminated in compliance with the necessary safety measures.

If defects are detected, the elimination of which is associated with hot work, the pipeline must be stopped, prepared for repair work in accordance with the instructions of the "Standard instructions for organizing hot work at explosive and explosive fire hazardous facilities", approved by Rostekhnadzor of the Russian Federation, and the defects must be eliminated.

The person responsible for the safe operation of pipelines is responsible for the timely elimination of defects.

2.5.3. The wall thickness is measured in areas operating in the most difficult conditions (elbows, tees, tie-ins, pipeline narrowing points, in front of and after fittings, places where moisture and corrosive products that cause corrosion accumulate - stagnant zones, drainages), as well as in straight sections intrashop and interdepartmental pipelines.

The number of measuring points for each section (element) is determined by the technical supervision department, provided that a reliable inspection of the pipelines is ensured.

On straight sections of pipelines of technological installations with a length of 20 m or less and inter-shop pipelines with a length of 100 m or less, the wall should be measured in at least 3 places. In all cases, the measurement should be made at 3-4 points along the perimeter, and at the branches at least 4-6 points along the convex and concave parts.

It is necessary to ensure the correctness and accuracy of measurements, to exclude the influence of foreign bodies (burrs, coke, corrosion products, etc.) on them. The measurement results are recorded in the pipeline passport.

2.5.4. The method of tapping with a hammer.

Mainly pipelines of IV, V categories are subjected to hammering. The pipelines are tapped along the entire perimeter of the pipe with a hammer weighing 1.0-1.5 kg with a handle at least 400 mm long with a spherical head. The condition of the pipe is determined by the sound or dents that form when tapped. The issue of partial or complete removal of insulation during an audit is decided by the technical supervision service in each case, provided that a reliable audit is ensured. If, according to the results of tapping, it is impossible to accurately judge the safe operation of the pipeline, it is necessary to measure the wall thickness.

An internal inspection of a section of the pipeline is carried out using an endoscope, a magnifying glass or other means, if, as a result of measurements of the wall thickness and tapping of the pipeline, doubts arose in its condition; the inner surface must be cleaned of dirt and deposits, and, if necessary, pickled. In this case, a site should be selected that is operated in unfavorable conditions (where corrosion and erosion, hydraulic shocks, vibration, changes in flow direction, the formation of stagnant zones, etc. are possible). Dismantling a pipeline section in the presence of detachable joints is carried out by disassembling them, and this section is cut out on an all-welded pipeline. During the inspection, they check for corrosion, cracks, a decrease in the thickness of the walls of pipes and pipeline parts.

Questions to Consider:

When carrying out an audit of t / wires, which areas should you pay special attention to?

How many measurements of the wall thickness of the t / wire should be carried out when conducting an audit on straight sections of pipelines of technological installations with a length of 20 m or less?

How many measurements of the wall thickness of the t / wire should be carried out when conducting an audit on straight sections of inter-shop pipelines with a length of 100 m or less?

How many wall thickness measurements do you need to take at the bends?

What is the frequency of testing t / wires for strength and density?

What is the rejection size for t / wire with an outer diameter of 57 mm?

What is the rejection size for t / wire with an outer diameter of 108 mm?

What is the rejection size for t / wire with an outer diameter of 219 mm?

What is the rejection size for t / wire with an outer diameter of 325 mm?

2.5. Testing of pipelines for strength and density.

2.5.1. Process pipelines must be tested for strength and tightness before putting them into operation, after installation, repairs associated with welding, disassembly, after conservation or downtime for more than one year, when operating parameters change, as well as periodically at a time equal to double revision.

After disassembling a single flange connection, a pipeline associated with the replacement of gaskets, fittings or a separate element of the pipeline (tee, coil, etc.), it is allowed to test only for tightness. In this case, the newly installed fittings or pipeline element must be pre-tested for strength by test pressure.

Pipelines of groups A, B (a), B (b) except for tests on strength and tightness must be tested for tightness (additional pneumatic tightness test with determination of the pressure drop during the test).

The headers of individual apparatuses and systems operating without overpressure and sections of flare lines, as well as short discharge pipelines directly into the atmosphere from safety valves, are not tested for strength and tightness.

The test of the pipeline for strength and density is carried out simultaneously, it can be hydraulic or pneumatic. Preferably a hydraulic test should be used.

The test is usually carried out before covering the pipeline with thermal or anticorrosive insulation. It is allowed to test the pipeline with applied insulation, but in this case the mounting joints are left open.

The type of test and the test pressure are indicated in the project for each pipeline. In the absence of design data, the type of test is chosen by the technical management of the enterprise (the owner of the pipeline).

Before testing, make an external inspection of the pipelines. At the same time, they check the correct installation of the fittings, the ease of opening and closing the locking devices, as well as the removal of all temporary devices and the end of all welding work and heat treatment (if necessary).

The pipeline should be tested only after it has been completely assembled on permanent supports or hangers, tie-ins, fittings, bosses, fittings, drainage devices, drain lines and air vents have been installed.

The test pressure should be measured using at least two pressure gauges installed at the beginning and at the end of the tested pipeline.

Pressure gauges used for testing process pipelines must be checked and sealed.

The pipeline test is carried out under the guidance of the person responsible for the operation of the pipeline, in the presence of a representative of the organization that performed the work. The test results are recorded in the "Certificate of quality" or in the act (if the "Certificate" is not drawn up), followed by a note in the pipeline passport.

2.5.2. Hydraulic testing.

Hydraulic testing of the pipeline for strength and density is carried out simultaneously.

For hydraulic testing, use water at a temperature of +5 to +40 ° C or other non-corrosive, non-toxic, non-explosive, non-viscous liquids, such as kerosene, diesel fuel, light oil fractions.

At the same time, in order to avoid large losses of liquids and the rapid detection of leaks in the pipeline, careful supervision of possible leaks must be ensured.

If it is necessary to carry out tests at a negative ambient temperature, fluids should be used, the freezing point of which is lower than the test temperature from among those indicated above.

To check the strength, the pipeline is kept under test pressure for 5 minutes, after which, for the density test, the pressure in it is reduced to that specified in Appendix 8.

To check the density at operating pressure, the pipeline is inspected and the welded seams are tapped with a hammer weighing 1-1.5 kg. The blows are applied to the pipe next to the seam on both sides.

Defects detected during inspection (cracks, pores, leaks of detachable joints and glands, etc.) are eliminated only after the pressure in the pipeline has dropped to atmospheric. After elimination of the detected defects, the test should be repeated. Marking of welded seams is prohibited.

During the simultaneous hydraulic test of several pipelines for strength, the common load-bearing building structures must be checked.

The results of the hydraulic test for strength and density are considered satisfactory if during the test there was no pressure drop across the pressure gauge and no leakage and fogging appeared on the pipeline elements.

Questions to Consider:

What types of g / tests are carried out for t / wires of groups A, B (a), B (b)?

What pressure should be used to test the strength of t / wires operating with a pressure of more than 2 kg / cm 2?

What pressure should be used to test the density of t / wires operating with a pressure of more than 2 kg / cm 2?

What is the duration of the tightness test for t / wires of groups A, B (a), B (b)?

What is the permissible pressure drop during the tightness test of t / wires of groups B (a), B (b)?

For the repair of t / wires of which categories is it possible to use t / wires elements that do not have certificates or passports?

For which t / wires is it possible to use fittings that do not have certificates and markings?

2.6. Technical documentation for pipelines

The following technical documentation is kept for technological pipelines:

1. List of critical process pipelines for installation;

2. Passport of the pipeline;

3. Act of periodic external inspection of the pipeline;

4. Act of testing process pipelines for strength and density;

5. Act on repair and testing of fittings;

6. Operational logbook of pipelines (kept for pipelines on which a passport is not drawn up)

7. Log of installation and removal of plugs;

8. Documentation for safety valves:

operational passport for PPK;

technical passport for the PPK, technical passport of the cylindrical compression spring;

setting pressure sheet

revision and adjustment act.

The storage location for technical documentation is determined by the factory instructions, depending on the structure of the enterprise.

4. Control questions

How are pipelines classified depending on the operating parameters and properties of the transported medium?

On which technological pipelines it is necessary to have standardized passports?

On which process pipelines it is necessary to keep an operating log of the established form?

How often do maintenance personnel need to make entries in the logbook about the results of pipeline inspection?

When auditing pipelines, which areas need to be paid special attention to?

How many measurements of the pipeline wall thickness must be carried out when conducting an audit on straight sections of pipelines of technological installations with a length of 20 m or less?

How many measurements of the pipeline wall thickness must be carried out when conducting an audit on straight sections of inter-workshop pipelines with a length of 100 m or less?

How many wall thickness measurements do you need to take at the bends?

What is the frequency of testing pipelines for strength and tightness?

What is the rejection size for a pipeline with an outer diameter of 57 mm?

What is the rejection size for a pipeline with an outer diameter of 108 mm?

What is the rejection size for a 219 mm OD pipeline?

What is the rejection dimension for a pipeline with an outer diameter of 325 mm?

What types of g / tests are carried out for pipelines of groups A, B (a), B (b)?

What media are used for r / tests?

What pressure is it necessary to test the strength of pipelines operating with a pressure of more than 2 kg / cm 2?

What pressure is it necessary to test the density of pipelines operating with a pressure of more than 2 kg / cm 2?

What is the duration of the leak test of pipelines of groups A, B (a), B (b)?

What is the permissible pressure drop during the tightness test of pipelines of groups B (a), B (b)?

For the repair of pipelines, what categories is it possible to use pipeline elements that do not have certificates or passports?

For which pipelines it is possible to use fittings without passports and markings?

Appendix # 1.

Group

Name

R slave kgf / cm 2

T slave,

0 C

R slave kgf / cm 2

T slave,

0 C

R slave kgf / cm 2

T slave,

0 C

R slave kgf / cm 2

T slave,

0 C

R slave kgf / cm 2

T slave,

0 C

Substances with toxic effects:

a) extremely and highly hazardous substances of classes I and II (GOST 12.1.007-76) - benzene, acids, hydrogen sulfide, tetraethyl lead, phenol, chlorine

b) moderately hazardous substances of class III - ammonia, methyl alcohol, toluene, solutions of caustic alkalis (more than 10%)

c) freon

Independently

St. 16

Vacuum below 0.8

Above 16

Independently

From + 300 to +700 and below –40

Independently

-«-

Vacuum 0.8 to 16

Up to 16

-40 to +300

Independently

Explosive and fire hazardous substances according to GOST 12.1.004-76

a) combustible gases

b) Flammable liquids (flammable liquids) - acetone, gasoline, kerosene, oil, diesel fuel

c) Combustible liquids (GZh) - fuel oil, oils, tar, asphalt, bitumen, oil distillates

Above 25

Vacuum 0.8

Above 25

Vacuum below 0.8

Above 63

Vacuum below 0.03

Independently

-«-

Above +300 and below -40

Above +300 and below -40

Above +350 and below -40

Above +350 and below -40

Vacuum 0.8

Up to 25

Above 16 to 25

Vacuum below 0.95 to 0.8

Above 25 to 63

Vacuum below 0.08

-40 to +300

Up to 16

-40 to +300

Above +250 to +360

Too

-40 to +120

Above 16 to 25

Vacuum below 0.95 to 0.08

Above +120 to +250

-40 to +120

Up to 16

-40 to +120

Non-combustible (TG) and non-combustible substances (NG) in accordance with GOST 12.1.044

Vacuum below 0.03

St. 63

Vacuum below 0.8

St. + 350 to +450

Over 25 to 63

From +250 to +350

St. 16

up to 25

St. + 120 to +250

Up to 16

-40 to +120

Appendix # 2

Appendix No. 3

Appendix No. 4

Appendix No. 5

Operational log of non-certified pipelines

Table # 1

P / p No.

Line name

Frequency of revision

Table 2

P / p No.

Date of the audit

Information about the replacement and repair of the pipeline

Responsible person's signature

Appendix No. 6

Appendix No. 7

Transported

Wednesday

pipeline

Inspection frequency at corrosion rate, mm / year

more than 0.5

0,1-0,5

up to 0.1

Group A environments

I and II

at least once a year

at least once every 2 years

at least once every 3 years

Environments of groups B (a), B (b)

I and II

at least once a year

at least once a year

at least once every 2 years

at least once every 3 years

at least 1 time in 3 years at least 1 time in 4 years

Environments of groups B (c)

I and II

III and IV

at least once a year

at least once a year

at least once every 2 years

at least once every 3 years

at least once every 3 years

at least once every 4 years

Group B environments

I and II

III and IV, V

at least once every 2 years

at least once every 3 years

at least once every 4 years

at least once every 6 years

at least once every 6 years

at least once every 6 years

Appendix No. 8.

Purpose of the pipeline

Pressure, kgf / cm 2

Strength

On density

All process pipelines, except those specified in

p. 2,3,4

Rpr = 1.12Rrab * 20/  t

Rrab

Pipelines transporting flammable, toxic and liquefied gases at operating pressure:

• below 0.95 kgf / cm 2

  up to 0.05 kgf / cm 2

  from 0.05 to 0.5 kgf / cm 2

  from 0.5 (abs) to 2 kgf / cm 2

not produced

not produced

not produced

Rrab + 0.3

P slave but not less than 0.85

Flare lines

Gravity pipelines

Appendix No. 9.

Appendix No. 10

The scope of inspection of welded joints by ultrasonic or radiographic methods in% of the total number of welded joints by each welder (but not less than one joint)

Manufacturing conditions

When making a new or repairing an old pipeline

When welding dissimilar steels

When welding pipelines included in units of I category of explosion hazard

Appendix No. 11

Table 1.

Classification of pipelines PN =< 10 Мпа (100 кг/см²)

General

group

Transported

substances

Rrab., Mpa

(kg / cm ² )

t work.,

° C

Rrab., Mpa

(kg / cm ² )

t work.,

° C

Rrab., Mpa

(kg / cm ² )

t work.,

° C

Rrab., Mpa

(kg / cm ² )

t work.,

° C

Rrab., Mpa

(kg / cm ² )

t work.,

° C

Substances with toxic effects

a) extremely and highly hazardous substances of classes 1,2

(GOST 12.1.007)

b) moderately dangerous

Class 3 substances

(GOST 12.1.007)

Whatever

Over 2.5

(25)

Whatever

Over +300

and below -40

Vaccum

from 0.08

(0,8)

(abs)

up to 2.5 (25)

From -40

before

Explosive and fire hazardous substances GOST 12.0.044.

a) combustible gases (GG),

including liquefied (LPG)

Over 2.5

(25)

Vaccum

below 0.08

(0,8)

(abs)

Over +300

and below -40

Whatever

Vaccum

from 0.08

(0,8)

(abs)

up to 2.5 (25)

From -40

before

b) flammable liquids (flammable liquids)

c) flammable liquids (GZh)

Over 2.5

(25)

Vaccum

below 0.08

(0,8)

(abs)

Over 6.3

Vaccum

below 0.003

(0,03)

(abs)

Over +300

and below -40

Whatever

Over +350

and below -40

Also

Over 1.6 (16) to 2.5 (25)

Vaccum

above 0.08

(0,8)

(abs)

Over 2.5

(25) to

6,3 (63)

Vaccum

below 0.08

(0,8)

(abs)

+120 to +300

From -40

up to +300

Over +250

up to +350

Also

Up to 1.6 (16)

Over 1.6 (16)

up to 2.5 (25)

Vaccum

up to 0.08

(0,8)

(abs)

-40 to +120

Over +120

up to +250

-40 to +250

Up to 1.6 (16)

-40 to +120

Flame retardant (TG)

and non-flammable substances (NG) in accordance with GOST 12.1.044

Vaccum

below 0.003

(0,03)

(abs)

Above 6.3 (63) vacuum below 0.08

(0,8)

(abs)

Over +350

up to +450

Over 2.5 (25)

up to 6.3 (63)

From +250

before

Over 1.6 (16)

up to 2.5 (25)

Over +120

up to +250

Up to 1.6 (16)

-40 to +120

Notes. 1 . The designation of the group of a certain transported medium includes the designation of the general group of the medium (A, B, C) and the designation of the subgroup (a, b, c), reflecting the hazard class of the transported substance.

2. The designation of the pipeline group in general corresponds to the designation of the group of the transported medium. The designation "pipeline of group A (b)" denotes the pipeline through which the medium of group A (b) is transported.

A group of pipelines carrying a medium, consisting of various components, is installed by component,

requiring the attribution of the pipeline to a more responsible group. Moreover, if, when contained in a mixture of hazardous

substances 1, 2 and 3 hazard classes, the concentration of one of the components is lethal, the group of the mixture is determined by this

substance.

In the event that the most dangerous component in terms of physicochemical properties is included in the mixture in an insignificant

quantity, the issue of attributing the pipeline to a less critical group or category is decided by the project

The hazard class of hazardous substances should be determined in accordance with GOST 12.1.005 and GOST 12.1.007, the values ​​of the indicators of fire and explosion hazard of substances - according to the relevant NTD or the methods set forth in GOST 12.1.044.

For vacuum lines, it is not the nominal pressure that should be taken into account, but the absolute operating pressure.

Pipelines transporting substances with an operating temperature equal to or higher than their autoignition temperature or an operating temperature below minus 40 ° C, as well as incompatible with water or air oxygen under normal conditions, should be classified as category 1.

A. A Persion K. A. Garus,

laureates of the State Prize of the Ukrainian SSR

Provides reference data on the manufacture and installation of pipelines for various purposes (technological, water supply systems, sewerage, etc.). A brief description and technical characteristics of equipment and special devices used in the manufacture of sections, assemblies of steel pipelines, welded and molded parts of plastic pipelines, cleaning, priming, anticorrosive insulation of pipes and installation of pipeline systems are given. Regulatory materials are as of January 1, 1987.

For workers and foremen involved in the installation of pipelines.

Reviewers engineers A.M. Meged, B.E. Aizin

Edition of literature on special and installation work in construction

Head edited by S. I Sotnichenko

FOREWORD

The main task of capital construction in the XII Five-Year Plan is the creation and accelerated renewal of fixed assets of the national economy, intended for the development of social production and the solution of social issues, a radical increase in the efficiency of construction production.

For its successful implementation, the Main directions of economic and social development of the USSR for 1986-1990 and for the period up to 2000 envisage: “Consistently carry out further industrialization of construction production, turning it into a single process of erecting objects from prefabricated elements. Switch over to the complete supply of engineering and technological equipment to construction sites in enlarged blocks ... To reduce by about 25 percent the volume of manual work. "1

Resolutions of the Central Committee of the CPSU and the Council of Ministers of the USSR "On further improving the management of the country's building complex" and "On measures to improve the economic mechanism in capital construction" mechanization and industrialization of construction processes, widespread introduction of effective products and materials into practice.

The restructuring of the country's construction complex is aimed at accelerating the commissioning of production capacities on the basis of the widespread introduction of the achievements of science and technology into practice.

For the industrialization of work on the construction of pipelines for various purposes, construction and installation organizations of the Ukrainian SSR are constructing new, reconstructing and technically updating the existing pipe procurement shops. They are equipped with advanced equipment for cutting pipes, assembling units and sections, mechanized welding, quality control of welded seams, etc.

The use of ready-made assemblies and sections, centrally manufactured in pipe procurement shops, makes it possible to simplify the technology and organization of the installation of pipelines, by 2.5-3 times to reduce the volume of labor-intensive work performed at the construction site.

The reference book systematizes progressive developments of research and design institutes, industrial organizations in the field of manufacturing and installation of pipelines for various purposes, in particular the Institute of Electric Welding named after V.I. EO Patoia of the Academy of Sciences of the Ukrainian SSR, VNII-moitazhepetsstroy, Giproieftespetsmontazh, All-Union Institute of Welding Production.

Chapters 1-12 are written by A.A. Persioiom, chapter 13 by K.A.Garus.

Technological pipeline installer

I. History of pipeline development

It is difficult to pinpoint the exact time of the invention of the first wheel, but it is known for certain that the first pipes appeared in the Stone Age. A shrewd primitive man, using a tree trunk with a rotten core, realized that the easiest and simplest way to get water directly into a dwelling is a pipeline. As technology progressed, the pipe material changed. All efforts were directed to ease of manufacture, reliability and durability of pipelines. The availability of raw materials from which the pipes were made played a significant role. The wooden pipeline has served mankind for a long time: in the 17th century, a wooden water pipeline functioned in London, which served 200 years; in Boston (USA), the water supply served from the middle of the 17th to the middle of the 18th century; in Russia, the last mention of the use of wooden pipes for water supply dates back to the middle of the 18th century. In St. Petersburg, the Samsonievsky water pipeline was laid to the Samson fountain, which served for about 30 years.

With the development of the smelting business, mankind used the most available materials. This is how lead, cast iron, steel, stone cast, and reinforced concrete pipes appeared. In Russia, the water supply was mainly steel pipes and, to a lesser extent, cast iron pipes. In the middle of the 20th century, pipes made of polymer materials appeared and gradually began to replace the traditional steel pipes used in the construction industry.

The beginning of the new century is characterized by a significant increase in Russia's economic activity. Vigorous development is taking place in the country, new complexes of shops, gas stations and other facilities are opening. The construction of external pipelines turns out to be a truly demanded service, since real comfort is unthinkable without competently provided communication systems. Not to mention the fact that without them, the structure will simply not be allowed for operation by the relevant government agencies.

II. Introduction to the specialty

A pipeline is a structure made of pipes, tightly connected to each other, for the transportation of various products (water, gas, oil). Depending on the location, pipelines are divided into internal and external.

Pipelines are laid and installed by installers of technological pipelines (from the French "montage" - lifting, installation and assembly of a product).

Technological pipelines installers carry out work on the laying of external and internal pipelines, including gas and water supply pipelines, heat supply pipelines, special-purpose pipelines (oil pipelines, fuel oil pipelines, vacuum pipelines, etc.); arrangement of prefabricated collectors, channels, chambers and wells of all types and purposes ...

In most cases, pipes are laid in the ground at a depth where the ground will not freeze in the harshest winters. And this is a depth of more than one and a half meters. Such deep pipe trenches are dug by special excavators.

With the help of a pipelayer, workers lay links and single pipes, close up joints and sockets of pressure pipelines, lay reinforced concrete slabs of the base and floors of collectors, channels, chambers and wells. Pipes are cut into the existing engineering network.

After laying the pipeline, the workers perform a hydraulic test of the pipes for joint tightness and strength, and twice. The first time the pipeline is tested before backfilling the trenches (preliminary test) and the second time after backfilling with soil to the full height of the trench (final test).

After pipe laying, connection and preliminary testing, the pipeline installers backfill the pipeline trenches with soil. At the same time, they make sure that stones, fragments of concrete, large blocks of frozen soil do not fall on the pipeline along with the ground. Before filling the trench with a bulldozer, first, the soil is manually driven under the pipes and sequentially compacted in the sinuses between the pipes and the trench wall to the height of the pipe. They are compacted mechanically, and sometimes manually by rammers.

Water pipes are flushed with chlorinated water prior to commissioning. This operation is very responsible, because a dirty pipeline can cause massive illness and poisoning.

Installers of external pipelines cut safety and shut-off valves into the pipeline, install special supports and brackets for pipelines and cables. Cylinders of reinforced concrete wells, collectors, necks of wells and chambers, etc. are mounted.

III. Features of professional activity.

As a rule, an installer working in construction has a standardized working day: from 8-00 to 17-00 with an hour-long lunch break. However, depending on the enterprise and the work plan, fitters can work in shifts and on a rotational basis (with business trips).

Fitters work outdoors at any time of the year. Installation work stops in winter at temperatures below 30 degrees, ice, rain, snow. On cold days, installers take heating breaks. For this, insulated household premises are used. During work, the installer has to use physical force, so men work as installers of technological pipelines.

IV. Demand for the profession

Installation of pipelines is a complex and time-consuming process. It is impossible to carry out quality work without specially trained workers. The result of their labor is often hidden from us under the thickness of the earth: after the work carried out, the pipeline cannot be seen. But without it, not a single building will come to life: there will be no water, no gas, no heat, so necessary for people. Therefore, assemblers of external pipelines in construction have been and will be in demand in the future.

V. Knowledge is power

To successfully master the profession, an installer of external pipelines needs knowledge of the laws of physics, especially its applied sections - mechanics, hydraulics, electrical engineering; foundations of mathematics, technical drawing. Need training in materials science. The installer of technological pipelines is obliged to understand a lot. He must know and have deeper knowledge, strictly observe the requirements for the use of various materials, follow the rules and special technological requirements for the manufacture and installation of pipelines and improve the quality of work.

Vi. Professional growth prospects

Increasing the grade (the profession has 2-6 grades), wages, the complexity of the work performed; expansion of professional skills by increasing the types of work performed, retraining for related professions.

Skills can be improved at the workplace and at training centers. Administrative growth is possible. After graduating from a technical school or institute in a construction specialty, you can work as a foreman, foreman or engineer.

Vii. Come - we will teach

Persons with basic general secondary education (9 classes) are allowed to prepare. Upon completion of training and passing the qualification exam, a qualification grade - 4 is assigned and a diploma of a qualified worker is issued. The term of study is 3 years.

There is a possibility of transferring to the 3rd stage of training in the specialty "mechanical technician for the installation of industrial equipment" with obtaining the qualification "junior specialist".

VIII. Requirements for individual characteristics.

The profession of an installer imposes certain requirements on the psychological, psychophysiological characteristics of a person, as well as on his state of health.

Good physical health is essential for work. Performing work, you need to be confident in your abilities, coordinate your movements well, be dexterous. A good eye helps professionals to correctly lay out pipes in a trench, to fit them together, to accurately observe the necessary distances (gaps) that are supposed to be left between the pipe walls. Studying the drawings, working on assembly diagrams, the installer must be able to translate the language of symbols into the language of practical actions, which requires a recreational imagination.

Solving various production problems requires from the installer not only practical experience and theoretical knowledge, but also the ability to foresee the course of events, the ability to plan their actions, control the correct installation, and develop the most rational way of working.

IX. Medical contraindications:

Diseases of the cardiovascular system, musculoskeletal system, visual impairment, hearing impairment, neuropsychiatric diseases.

Unified tariff and qualification reference book of jobs and professions of workers (ETKS), 2014
Issue No. 3 ETKS

1. Introduction.

2. Kinds of appointment of the device of the device used in the installation of external pipelines.

3. Promising types of welding.

3.1. Methods that increase labor productivity.

3.2 Welding methods that increase labor productivity.

4. Labor protection.

4.1. Electrical safety.

4.2. Fire safety.

6. Literature.

Introduction.

During the construction of enterprises of the oil, chemical, food, metallurgical industries, as well as facilities for the production of mineral fertilizers and the agro-industrial complex, a significant amount is made up of work on the manufacture and installation of technological pipelines.

In the total volume of installation work, the cost of installing technological pipelines reaches 65% during the construction of oil and petrochemical enterprises, 40% - chemical and food, 25% - metallurgical.

Process pipelines operate in a variety of conditions, are exposed to significant pressures and high temperatures, corrode and undergo periodic cooling and heating. Due to the expansion of the unit capacity of the facilities under construction, their design is becoming more and more complex from year to year due to an increase in the operating parameters of the transported substance and an increase in the diameters of pipelines.

For the construction of technological pipelines, especially in the chemical and food industries, polymer materials are increasingly used. The increase in the volume and scope of these pipes is explained by their high corrosion resistance, lower weight, processability of processing and welding, low thermal conductivity and, as a consequence, lower costs for thermal insulation.

All this requires from installers deeper knowledge, strict adherence to the requirements for the use of various materials, compliance with the rules and special technological requirements for the manufacture and installation of pipelines.

In recent years, industrial methods of pipeline work have been introduced on a large scale, which provides a 40% increase in labor productivity and 3-4 times reduces the volume of work performed directly at the installation site, while the time for installing pipelines is reduced by three times. The essence of the industrialization of pipeline works lies in the transfer of all pipe procurement works to factory conditions, meaning to turn construction production into a complex mechanized process of assembling objects from ready-made assemblies and prefabricated blocks.

Types of purpose of the device of the device used in the installation of external pipelines.

External pipelines are mounted in enlarged blocks or sections. Installation of inter-workshop pipelines with separate pipes is allowed only in cases where, due to the constrained conditions, laying in sections becomes impossible.

By the type of enlargement, blocks can be of building structures, pipeline and combined.

Blocks from building structures are used in the construction of prefabricated reinforced concrete and metal racks of beam and truss types. The block of building structures of reinforced concrete girder overpasses includes beams, traverses, walkways and their fences, and metal trusses - trusses, upper and lower beams, link elements, walkways and their fences.

The pipeline blocks may include: straight pipeline sections, consisting of one or several sections (within the temperature block); satellites; U-shaped, lens or stuffing box expansion joints; thermal insulation.

A combined unit is a flyover superstructure assembled before lifting with installed and fixed pipeline units.

The choice of the type of block and the degree of its enlargement is determined by the PPR depending on the design solutions of the ramps, the number and location of pipelines, their diameters, the availability of lifting mechanisms and vehicles, as well as local conditions of work. Typically, installation is carried out by pipeline and combined units.

Aggregate assembly of blocks is carried out at assembly sites - movable or stationary, which are located in the area of ​​operation of the assembly crane.

A diagram of a movable platform for assembling pipeline blocks up to 60 m long, laid on a metal truss overpass, is shown in Fig. 3. Pipeline blocks are assembled in the following sequence: load, transport and unload fittings, parts, units and sections; install racks or stands; prepare the edges of the sections for welding; sling the sections, lift and put them on the racks; assemble and weld joints, control the quality of welded joints; mark the installation sites of the supports and fix the supports; control quality, mark and accept blocks.

When broken down into blocks, the length of pipelines laid on free-standing racks, as well as outside the cross-sectional contour of the overpass, is taken at D y less than 150mm and more than 400mm no more than 36m, from 200 to 400mm - no more than 60m.

When assembling the blocks, the locations of the supports are marked out according to the project (taking into account the displacement of the supports under the influence of thermal expansion), as well as according to the placement of the supporting structures taken from nature (taking into account their deviation from the design position). With pre-installation thermal insulation of blocks, at the joints of the pipes, they are left with uninsulated sections with a length of at least 500 mm and at the ends of the blocks - at least 250 mm. Pre-insulation of steam and hot water pipelines registered by Gosgortekhnadzor is not allowed.

A diagram of a stationary site for the assembly of combined blocks laid on a metal truss overpass is shown in Fig. 4. Combined blocks are mounted in the following sequence: loading, transporting and unloading enlarged elements of building structures and pipeline sections; assembling pipeline blocks; lay out and fix the lower beams; set up farms; install the upper racks, fix the "Christmas trees"; laying and temporarily fixing pipeline blocks placed inside the cross-sectional contour of the block; install the upper beams, semi-beams and ties of the upper belt; arrange elements of rigidity; mark and accept the block.

Temporary stiffeners (spacers or ties) must prevent the possibility of breakage and deformation of the blocks during their transportation and installation. The designs and installation locations of such elements are determined by the PPR. Temporary fastening of pipelines in combined blocks is performed with clamps at the points where the pipeline rests on building structures at least at two points for each block.

When installing structures of span structures of overpasses and pipelines, it is necessary to ensure the stability and invariability of the mounted part of the overpass.

Installation work on the laying of external inter-workshop pipelines on free-standing supports or overpasses is started only after receiving from the construction organization acts on the full compliance of the supporting structures with the project and technical conditions, as well as checking the actual performance of these works by representatives of the installation organizations.

For interdepartmental pipelines, an act of routing is drawn up. Attached to the act is a list of axes and rotations with an indication of the signs placed on the racks or applied with indelible paint on the walls.

It is necessary to check the readiness of the building structures of the racks of overpasses (for combined and pipeline blocks laid on free-standing stands) and span structures (for pipeline blocks) for installation and draw up an executive scheme that takes into account the deviation of marks and the position in the plan of the support structures of the overpass.

The complex of works on the installation of blocks includes: the device of the scaffold; breakdown of pipelines' axes; slinging; lifting and installation of blocks in the design position; temporary fastening of blocks; unfastening; assembly of assembly joints; welding of joints; testing and acceptance of pipelines; sealing joints of thermal insulation.

Installation within each temperature block begins only after the installation of intermediate fixed (anchor) racks with all welded joints.

When laying pipelines located inside the cross-sectional contour of the overpass, pipeline blocks, depending on the type of overpasses, can be mounted using several methods: pre-laying the blocks inside the cross-sectional contour of the overpass before installing the structures of the upper tier (for prefabricated reinforced concrete two-tier beam-type overpasses); loading pipeline blocks into the open end of the overpass (for all types of overpasses); by winding blocks inside the contour through a specially provided for this opening in the plane of the upper belt of the overpass (for metal truss-type overpasses).

The erection of the structures of the span structures of the flyover begins from a fixed (anchor) rack and leads to both sides of it.

When assembling pipeline and combined units at stationary assembly sites or in pipe procurement shops, it is advisable to mount them directly from vehicles, which makes it possible to exclude intermediate operations for storing and slinging goods. In this case, the blocks are transported directly to the area of ​​operation of the assembly crane and are gradually installed on the overpass.

Combined blocks of two-tier reinforced concrete overpasses are mounted only after the installation of all inserts is completed (stage I) and the inserts are welded with support posts. Traverses and ties along the upper tier are installed after the combined blocks are installed on the lower tier and pipelines are laid in it, suspended from the upper tier, if this is allowed by the structure of the overpass.

Combined blocks of a metal truss overpass are mounted with one crane 2, with the exception of compensatory blocks, which are mounted with two cranes. Combined block 1 is brought to the design position by aligning the mounting holes, alignment lines or supporting embedded parts with the corresponding mounting locations of previously mounted structures of span structures or supports. To avoid impact, the block is induced by very small movements of the assembly crane, as well as by manually tensioning the braces (at least two) with assembly crowbars, clamps and jacks.

The blocks are temporarily fixed with mounting bolts, clamps and other inventory fixtures prior to alignment. The slings are removed after checking the correct installation and securing the mounted blocks. The process pipelines and fittings are finally fastened, and the assembly joints are welded after the installation of the overpass section that makes up the temperature block. In this case, the abutting sections and pipeline blocks are mutually displaced until the required gap is formed.

Reinforcement elements of block structures installed for the period of transportation and installation are dismantled only after the block is fully secured in the design position. In case of large-block installation of external pipelines on overpasses, laborious operations are assembly and welding of pipes between blocks, cutting and fitting of butt pipes, as well as regulation of the position of sections during assembly.

Installation of inter-shop pipelines in blocks and sections allows to mechanize 80 - 85% of procurement, assembly and welding, insulation and assembly works and significantly increase the quality and productivity of labor.

On the newly constructed overpasses, free space is left for the laying of additional pipelines in case of a possible expansion of the enterprise and an increase in capacity. Additional pipelines on existing ramps are usually laid in separate pipes (Fig. 8). Pipes 5 are lifted by crane 4 and with the help of a tractor 1 or winches and branch blocks 2 are dragged into the overpass 3.

Promising types of welding.

Methods that increase labor productivity.

Organizational measures to increase labor productivity include: timely provision of welders with serviceable, connected to the network welding equipment, welding materials and tools, hoses, cables, overalls, personal protective equipment; providing the welder with an equipped workplace and arranging safe approaches to it; timely preparation of parts for welding; provision of technological documentation; creation of the necessary production and living conditions.

Organizational and technological measures include: timely and quick connection of equipment and troubleshooting; supply of high-quality electrode holders and tools; provision of devices for fast turning of products or their tilting; production of the most efficient structures with a minimum amount of deposited metal in the finished product. Accurate implementation of organizational, organizational and technical measures along with the introduction of progressive forms of labor organization increases labor productivity by at least 15-20%.

If we consider the technical measures, the introduction of which makes it possible to increase the productivity of welding, the following should be noted.

· An increase in the density of the welding current with the selected diameter of the electrode in comparison with the passport data makes it possible to increase the productivity of manual welding by 1.5 - 2 times by increasing the welding speed and the depth of penetration of the base metal. The best technical and economic indicators for welding at high conditions are obtained when using electrodes with a diameter of 5 and 6 mm. However, it is not recommended to increase the welding current density above 12 - 14 A / mm 2 when welding with electrodes with a basic coating, as this leads to strong spattering of the electrode metal, a decrease in the deposition rate and a deterioration in the quality of the weld.

· Increasing the diameter of the electrode from 3 to 6 mm increases the welding productivity by 3 times (if the optimal welding mode is selected correctly for each diameter of the electrode). The use of electrodes of large diameters (8 and 10 mm) allows welding at an increased current and thereby increases the productivity of the process. However, when welding with such electrodes, the mass of the electrode and the holder increases, which causes fatigue for the welder. Difficulties arise in providing root penetration in narrow grooves of edges and fillet welds. In addition, during manual welding with high currents, magnetic blowing significantly increases, especially when welding with direct current, which complicates the welding process and leads to a decrease in the quality of the welded joint.

· The use of electrodes with iron powder or other metal additives in the coating is used to increase the deposition rate. The productivity of welding with such electrodes increases by 10 - 15% compared to welding with conventional electrodes. At the same time, the specific power consumption decreases (by about 20%)

The introduction of iron powder into the coating increases the deposition rate, increases the transition of the electrode metal into the seam, and improves the appearance of the seam. Small additions of iron powder (up to 14%) are used to stabilize the arc, medium and large (up to 50%) - to increase the productivity of the process. High-performance electrodes usually include electrodes for which the transition of the electrode metal into the seam due to the addition of iron powder to the coating is over 120%, for example, electrodes of the ANO-5 (11 g / A. H), ERS-1 (14 g / A. H) brands , OZS-3 (15 g / A. H). Electrodes of these grades are suitable for welding only in the lower position.

Welding methods that increase labor productivity.

Submerged arc welding, as opposed to conventional manual coated electrode welding (open arc welding), is called electrode welding or deep penetration welding.

To obtain deep penetration, special high-quality electrodes with a particularly thick coating are used, for example, the OZS-3 brand.

The electrode is supported by the visor formed during melting on the metal being welded at an angle of 70 - 85 ° to the horizon for better displacement of liquid metal from the crater (Fig. 9). When welding, the arc is immersed in the base metal, and the edges of the visor protect the electrode from a short circuit. The short arc in immersion welding is maintained automatically by the support of the cover plate on the base metal. A high concentration of heat in a short arc increases the penetration depth. When welding with deep penetration, the loss of metal as a result of waste and spatter is minimal. Welding is carried out at a high strength of the welding current at an increased speed.

This method is most effective when welding fillet and tee joints in the lower position, but it is also used when welding butt joints.

Submerged arc welding requires careful preparation of the welded product: the surface along the seam is cleaned of rust, the gap between the edges should not exceed 10% of the metal thickness of the product.

Deep penetration welding differs from conventional manual welding with a higher welding current and a faster welding speed. In addition, it has the following advantages: eliminates the need to hold the electrode on weight, which facilitates the work of the welder; good penetration of the root of the seam is ensured; welding of sheets up to 20mm thick is possible without beveling the edges; skills of a welder are acquired within a few days; no high qualification of a welder is required; labor productivity increases 2 - 3 times.

Welding with support in a vertical position from top to bottom can be performed with ANO-9 electrodes. When fillet welds are applied with an 8mm cutter, electrodes with a diameter of 4mm are used. Welding speed 10 m / h.

Welding with a beam (comb) of electrodes is carried out in the same ways as manual welding with one coated electrode. The welder simultaneously works with two, three or more electrodes, connected in a bundle by applying tacks at the point of their clamping into the electric holder. The electrodes are connected to each other with a soft wire (steel or copper with a diameter of 0.25 - 0.5 mm) along the length in 3 - 5 places, and from above - by welding. In this case, a conventional electric holder is used.

If the design of the electric holder allows you to hold several electrodes, there is no need to connect them at the grip.

The arc when welding with a beam of electrodes is first struck between one electrode and the work piece to be welded. When this electrode melts so much that the distance from its end to the product becomes large, the arc will extinguish and reappear between the product and the electrode that will be the closest to the product. The arc occurs alternately where the distance between the workpiece and the electrode becomes minimal, and gradually melts the electrodes. The process takes place continuously, just like when welding with one electrode.

When welding with a beam of electrodes, the current passes through individual electrodes for a short time, they heat up less than in conventional welding, and this makes it possible to apply a large welding current.

The use of this welding method is very effective in surfacing.

The disadvantages of welding with a beam of electrodes include its unsuitability for vertical and overhead welding, as well as the complexity of the manufacture of electrodes.

Flameless welding differs from conventional manual welding in that the electrode is not fixed in the holder, but welded to its end. Due to this, the loss of electrodes for cinders is eliminated, the strength of the welding current increases (by 10 - 15%) and the loss of time for changing the electrodes is reduced.

Flameless welding increases labor productivity, but it is not free from drawbacks: it becomes difficult to manipulate the electrode, which, with insufficient experience of the welder, negatively affects the quality of the welded joint; Welding the electrode in comparison with fixing it in a conventional electric holder is a more complicated operation.

Welding with a recumbent electrode consists in the fact that an electrode with a high-quality coating is not fed into the arc zone, but fits into the groove (Fig. 10). The arc, excited between the end of the electrode and the metal to be welded, moves along the length of the electrode, gradually melting it.

One or more electrodes with a diameter of 6-10 mm are placed in the groove of the seam. They put paper insulation on top and press it with a copper block.

Such welding is especially convenient in hard-to-reach places. The length of the electrode is taken equal to or a multiple of the length of the seam, and the cross-section of the seam is equal to the cross-section of the electrode rod. With this method of welding, one operator can serve several posts.

This welding method ensures high quality of the weld metal; productivity in comparison with manual welding increases by 1.5 - 2 times due to the use of large-diameter electrodes and a corresponding increase in the strength of the welding current; reduces the loss of metal to waste and splashing.

Welding with an inclined electrode is welding with a metal electrode, when an electrode with a high-quality coating is fed into the arc zone, which rests on the workpiece with its lower end, while the upper end is fixed in a special sliding electric holder (Fig. 11).

The support with the help of a magnet fixes the device on the surface of the metal to be welded. As it melts, the electrode moves under its own weight along the guide along the welding line. The electrode cover rests on the work piece to maintain a constant arc length. The upper part of the visor is longer than the lower one, so the arc deflects towards the welded product. The seam section is adjusted by changing the angle of inclination of the electrode.

There is also known a method of welding with an inclined electrode, in which the upper end of the electrode is hinged.

Three-phase arc welding is performed with special electrodes and electric holders. Manual welding and surfacing are performed in the following ways: with two electrodes fixed in two holders (Fig. 12, a); two parallel electrodes fixed in one holder (Fig. 12, b). The electrodes consist of two rods located at a distance of 5–6 mm from each other and covered with a coating, and the electrode holders have separate fixings and an electrical connection to the electrodes. The ends of the electrodes with one side (cleaned) are separately fixed in the electrode holder. When welding, one phase is supplied to the product, and two phases (separately) to the electrodes.

The productivity in welding with a three-phase arc, in comparison with conventional single-phase manual welding, increases by about 2 times, but the technique of execution is somewhat more complicated due to the increase in the mass of the electrode and holder. Three-phase arc welding skills are acquired rather quickly.

A three-phase arc is used to weld joints (butt and tee) in the lower position. Large weld beads are possible during welding. Therefore, T-joints should be welded “into a boat”. A decrease in porosity and an increase in penetration depth is achieved by welding by the method of supporting the electrodes.

When welding with two parallel electrodes clamped in one holder, the angle of inclination of the electrodes to the surface of the plate should be 65–70 °. With an excessively large angle of inclination, the liquid slag and metal flow forward onto the unmelted metal of the plate, as a result of which the penetration depth decreases. At a small angle of inclination, the liquid metal and slag are strongly pushed aside by the arc into the tail part of the weld pool, which disrupts the formation of the seam and increases spatter.

To obtain a wide roller, the electrodes must be given a transverse vibrational movement, the width of which for the longitudinal located electrodes should be no more than two diameters of the electrodes (Fig. 13, a), and for transversely located no more than four (Fig. 13, b).

In multilayer butt welding of plates with one-sided bevel of the edges, the first layer is performed with paired electrodes located along the seam (Fig. 14, a), and the subsequent ones - with transversely located electrodes (Fig. 14, b).

When welding overlapped plates, the electrodes should be located across the seam. In this case, the angle of inclination of the electrodes in the direction of welding should be 70 - 75 о (Fig. 15, a) and in relation to the surface of the parts 50 - 60 о (Fig. 15, b). In the process of welding, the electrodes perform transverse oscillatory movements with an oscillation amplitude of 2.5–3 electrode diameters.

A three-phase welding arc emits more radiation than a single-phase one, therefore the protective filters should be darker.

Bath arc welding (Fig. 16) is characterized by an increased size of the weld pool, held in a special shape (steel or ceramic). The steel mold is welded to the welded joint, the ceramic molds are made detachable and removed after welding. They are used for welding rod products (for example, reinforced concrete fittings and rails). Welding is carried out with one or more electrodes (Fig.) Of the UONI brand. Welding is performed at increased modes, which provides the necessary heating of the elements to be welded to create a large weld pool of liquid metal.

Welding begins at the bottom of the mold, in the gap between the ends of the rods. The electrode is first moved along the gap. During welding, the weld metal must be in a liquid state.

Welding with electric rivets is carried out with the penetration of the upper part with a welding arc without a hole in the upper sheet or through a previously prepared hole.

The welding method without a hole is used when the thickness of the top sheet is not more than 2 mm. The need to drill holes in the top sheets limits the range of applications for electric rivet welding. However, high productivity and ease of assembly of large-sized units when joining thin sheets with profiled rolled products contribute to the widespread use of electric rivet welding in industry.

In joints with sealed holes, the distance between the holes is 100–200 mm, and the hole diameter is 1–2.5 δ (δ is the sheet thickness, mm). Holes are drilled or punched on punch presses. When welding, the hole is completely fused with a slight bead from above. Electric rivets are not very durable.

Electrical safety.

Electrical injuries occur when an electric current passes through a person.

A current of 0.1A, regardless of its kind, is considered to be fatal to humans. With a minimum resistance of the human body of 600 ohms, a deadly current value (0.1A) is created at a voltage of only 60V.

The severity of an electric shock depends on the magnitude of the current and voltage, as well as on the path of the current in the human body, the duration of the current, the frequency (with an increase in the frequency of alternating current, the degree of injury decreases, alternating current is more dangerous than direct current).

Electric shock in industrial conditions most often occurs as a result of a person touching live parts that are under dangerous voltage.

Hazardous voltages can be step voltages that occur when electrical current flows into the ground. Current spreading is possible in cases of touching a broken electrical wire of the overhead network with the ground or when the protective grounding is triggered. If a person is in the current spreading zone, then a potential difference (step voltage) arises between the leg, which is closer to the ground electrode, and the leg that is separated from the ground electrode at a step distance (0.8 m), and a current circuit will close from leg to leg. Rubber shoes are used to protect against step voltage.

Rules for safe work with electrical installations.

Premises are divided into three categories according to the degree of danger of electric shock to people:

· Especially hazardous (high humidity, air temperature above +30 о С, chemically active environment, leading to destruction of insulation of live parts);

· With increased danger (conductive floors, the possibility of a person touching metal structures and cases of electrical equipment, etc.);

· Without increased danger (there is no danger of electric shock).

Electrical installations and devices are considered dangerous if their live parts are not fenced and are located at a height accessible to humans (less than 2.5 m), there is no grounding, grounding and protective shutdowns of conductive structures (metal cases of magnetic starters, buttons "start", "stop " and etc.).

Requirements for personnel serving electrical installations.

By the rules of technical operation of electrical installations, persons of five qualification groups are allowed to work on them:

· Qualification group I is assigned to personnel who have not passed the knowledge test according to the Rules for the technical operation of electrical installations.

· Qualification group II is assigned to persons who have basic technical knowledge of electrical installations (electric welders, electricians, etc.).

· Qualification group III is assigned to persons who have knowledge of special safety regulations for those types of work that are the responsibility of this person (electricians, technicians, etc.).

· Qualification group IV is assigned to persons with knowledge in electrical engineering within the scope of a specialized vocational school.

· Qualification group V is assigned to persons who know the schemes and equipment of their site, etc.

Fire safety.

The causes of fires in workshops are the presence of flammable substances and flammable liquids, liquefied combustible gases, solid combustible materials, containers and apparatus with flammable products under pressure, electrical installations that cause electric sparks during their operation, etc.

There are many reasons for the occurrence of fires: spontaneous combustion of some substances, if their storage is unsatisfactory, ignition by a flame, electric spark, liquid metal, slag, etc., it is customary to subdivide production into several categories on the basis of fire hazard: A - explosive, B - explosive, C - fire hazardous , D and D - non-flammable, E - explosive (there are only gases).

Welding works can be performed in premises of each production category in accordance with the requirements of GOST 12.3.002-75, GOST 12.3.003-75.

Welding work in closed containers must be carried out with the special permission of the administration of the enterprise.

The procedure for organizing and carrying out welding work in mines and mines is determined by the instructions approved by the Gosgortekhnadzor.

It is prohibited:

· Use clothes and gloves with traces of oils, fats, gasoline, kerosene and other hot liquids;

· Carry out cutting and welding of freshly painted structures until the paint is completely dry;

· Perform welding of devices under electrical voltage and vessels under pressure;

· Carry out cutting and welding of liquid fuel containers without special preparation.

Extinguishing media are water, foam, gases, steam, powder formulations, etc.

When extinguishing fires with water, water fire extinguishing installations, fire engines, water barrels (manual and fire monitors) are used. To supply water to these installations, special water pipes are used. To extinguish fires with water in most industrial and public buildings, internal fire hydrants are installed on the internal water supply network.

Foam is a concentrated emulsion of carbon dioxide in an aqueous solution of mineral salts containing a foaming agent. To obtain air-mechanical foam, air-foam barrels, foam generators and foam sprinklers are used. Foam generators and foam sprinklers are installed in stationary installations for water-foam fire extinguishing. When extinguishing fires with gases, steam, carbon dioxide, nitrogen, flue gases, etc. are used.

Each welding station must have a fire extinguisher, a tank or bucket of water, as well as a box of sand and a shovel. After finishing the welding work, it is necessary to check the working room and the area where the welding work was carried out, and do not leave open flames and smoldering objects. There are special fire-fighting units in the shops, voluntary fire brigades are created from among those working in the shop.

Conclusion.

I, Trukhanovich Evgeny Anatolyevich, studied at MGPTU No. 31 for one year, after the 11th grade, during which time I learned how to perform assembly and welding work.

He did his internship at the 15th trust, worked as an installer of external pipelines, and performed restoration work.

Special thanks to: G.S. Laschuk, M.Yu. Osipov. and the teacher of a special subject Bogansky I.I.

Literature.

1. Vinogradov Yu.G., Orlov K.S. Materials science for fitters. M. 1983

2. Zaitsev A.V., Polosin M.D. Automotive cranes. M. 1983

3. Kikhchik N.N. Rigging works in construction. M. 1983

4. Lupachev V.G. Manual arc welding. Mn. 2006

6. Tavastsherna R.I. Installation of technological pipelines. Moscow 1980