The ability to monitor the changing pressure in the operating system helps to optimize the operation of the pipeline equipment for operation in the most favorable conditions. The design of the special fittings ensures the implementation of complex circuits for connecting measuring equipment.
Most often, a three-way valve for a pressure gauge is used to connect a measuring device to a pipeline at a special pressure take-off point. If necessary, shut-off valves can be used to carefully relieve pressure before dismantling the gauge device. A special three-way ball valve for a manometer, equipped with flanges, provides the ability to conveniently connect a calibration device to check the correctness of the readings of the main operating device.
Our assortment includes three-way valves, differing in installation dimensions, design and nominal diameter. A variety of available offers allows you to buy a three-way valve for a pressure gauge that has the required technical characteristics. Wear-resistant brass products are adapted for many years of service without deterioration of the primary characteristics. For the most convenient use, the specialized shut-off valves are equipped with an adjustment knob in the form of a lever or a butterfly. For installation in various system configurations, products are supplied equipped with coupling and flange connections. A practical three-way coupling valve for a pressure gauge can be easily mounted on the corresponding section of the pipeline.
The choice of the optimal modification of the shut-off valves is made taking into account the technical characteristics of the pipeline systems in use. A classic three-way tension valve for a manometer can be used to quickly connect manometric equipment to a pipeline to monitor changing pressure. A variety of standard sizes of shut-off valves allows you to buy a three-way valve for a pressure gauge of the used modification. Brass taps, adapted to operate in a wide temperature range, can be installed in the water supply network and the heating main. Durable three-way valve for 1/2 manometer is resistant to pressure drops, temperature fluctuations, high humidity and mechanical stress. The design of the device ensures quick installation and stable operation. The high quality of the thread allows you to install a three-way valve under a 1/2 manometer as quickly as possible without performing additional operations. Typical connections provide quick installation and stable tightness of the operated system. A small-sized three-way ball valve for a pressure gauge combines an ergonomic design, high strength and guaranteed reliability. The use of specialized shut-off valves allows you to dismantle the pressure gauge for inspection without the need for a repair shutdown of the operating system.
Three-way valve for manometer. What is a three-way pressure gauge valve used for? Varieties of three-way valves for a pressure gauge. Features of installation and maintenance.
A three-way valve for a manometer is a device that is installed on the pipeline directly before the measuring manometer. Such taps are used in various communications, including: hot and cold water pipelines, steam pipelines, as well as in gas cylinders. The main function of the three-way valve is to ensure the safe operation of the measuring device.
What is a 3-way pressure gauge valve used for?
Such valves are called three-way because they have three taps (in / out). The principle of operation of this device is quite simple: the plug has a cut in the shape of the letter "T", which, during its rotation, coincides with one or two taps. A valve of this type performs several main functions that are worth paying attention to:
- such a valve allows the pressure gauge to be checked if necessary. The check is carried out using a pressure gauge, which is called a control one;
- a three-way valve is installed under the pressure gauge and protects the device from excessive pressure and overloads;
- if necessary, this type of shut-off and control valves allows you to disconnect a specific measuring device from communication;
- it becomes possible to purge the pressure gauge outlet. Thus, the instrument is protected from contamination and the accuracy of its readings does not deteriorate over time.
A three-way valve must necessarily be equipped with pipeline communications used for production purposes. Otherwise, there will be no pressure control in front of the pressure gauges, which will distort the readings of the measuring device, and may also cause an emergency in the system.
For communications that are used for private purposes, as a rule, the installation of such a device is not required. For utility pipelines, there is an alternative to this product - a coupling valve. Coupling valves are ideal for low pressure systems.
Varieties of devices
Today, there are three main types of three-way valves that are ubiquitous:
- cork tension;
- ball type with drainage;
- ball-type with a coupling outlet.
Three-way cork tension valve for manometer. It can have the following versions:
- two branches that are connected directly to the ends of the pipes, and one branch for drainage;
- each of the bends performs its own functions (pipe, metric and drainage);
- model with pipe, metric and drain outlet, equipped with a handle. The handle can be in the form of a lever or a butterfly;
- model with two pipe outlets and a flange, which is necessary for mounting a test pressure gauge during testing.
From a constructive point of view, such a device is very simple, however, it has several tangible disadvantages:
- quite a lot of effort is needed to switch the valve;
- when tightening the nut, there is a risk that the tail of the plug will be ripped off.
Three-way ball valves with drainage. Such products are made from an alloy of brass and differ from other taps in that they have a drainage hole. The drainage outlet is located on one side of the ball lock, which allows the device to function. The drainage outlet is equipped with a special screw that serves as a plug.
For such valves, the maximum pressure indicator does not exceed 1.6 MPa. As for the temperature, the drainage models are able to withstand +140 ° C in the communications transporting water. The maximum operating temperature of a ball valve for a pressure gauge in pipelines transporting steam is 225 ° C.
Ball valve with coupling outlet. Such products are considered the most simple (from a constructive point of view). A three-way ball valve for coupling under a pressure gauge is made of an alloy of brass, which is equipped with a chromium interlayer to increase its anti-corrosion properties. The sealing elements in such a faucet are made of Teflon.
The maximum temperature at which normal operation of this device is possible does not exceed 150 ° C. The main advantage of such a crane is its durability (approximately 20,000 cycles).
Features of installation and maintenance
The installation of a three-way ball valve does not differ from any other device that belongs to shut-off and control mechanisms. To enhance the tightness indicators during the installation of such valves, special sealing materials (FUM-tape, hemp, etc.) are used.
Experts recommend tightening such devices by hand, since brass does not have high strength characteristics and can crack. If necessary, you can use a wrench. Three-way ball valves for manometers, by their configuration, are non-separable devices, so it is impossible to repair such a product with your own hands in the event of a breakdown. Repair of such a device is possible only in one situation - if the crane is clogged with debris from the inside.
In addition, when the valve is closed, and the medium transported through the communication continues to move, you should pay attention to the tightness of the cork clamping. In addition, such a problem can arise as a result of clogging of the crane mechanism.
According to the rules of SNiP, a three-way valve must be installed in the pipeline system in front of the pressure gauge, which allows purging, checking or switching off the pressure gauge. Three-way taps for measuring manometers are used when installing steam, hot and cold water pipelines.
They are also used on cylinders and pipelines with oxygen, nitrogen, natural gas, carbon dioxide, oils and other neutral liquids and gases.
The task of pressure gauges in this design is to show the pressure in a cylinder or pipeline. The valve, in turn, must ensure safety and the correctness of the manometer.
Content of the article
What is a gauge valve for?
The installation of a 3-way gauge valve has the following objectives:
- the ability to check the device by connecting a control pressure gauge to it;
- the ability to relieve pressure in front of the device, which protects it from sticking arrows;
- the ability to disconnect the pressure gauge from the system;
- the ability to purge the manometric outlet in order to remove contaminants that negatively affect the accuracy of the measuring device.
For industrial purposes and in industries where constant monitoring of the pressure on the pipelines is required, the installation of such a device is mandatory.
Failure to follow this rule can be costly, as incorrect meter readings and lack of pressure control can damage the pipeline.
At home, instead of a tap, often use a straight-through coupling valve, since the pressure in the home system is much lower.
Modes of operation
Depending on the position of the locking mechanism, it can be in the following operating modes:
- direct the working medium from the line to the pressure gauge;
- the direction to the pressure gauge is closed. The pressure gauge is unloaded, the working medium flows freely through the pipeline;
- performed on a measuring device with a closed pipeline;
- if the locking mechanism is turned incorrectly, the valve can connect the line to the atmosphere. However, in this case, a 3 mm hole will remain for the passage of the working medium, which will avoid damage to the pressure gauge.
Types of cranes
Based on the fastening methods and internal design, there are three main types of valves.
It got its name from the method of sealing and the type of locking mechanism.
It has many advantages over analogues:
- simplicity of the design itself;
- high degree of tightness;
- small size;
- ease of installation and ease of use;
- elementary flow zones that do not have zones of debris accumulation;
- possibility of application in viscous or stagnant zones.
It got its name from the features of the inside of the locking mechanism. Inside the structure there is a ball with a slot in the form of the letter "G" or the letter "T".
Made in the same modifications as cork, but the first always equipped with a locking handle.
Overview of three-way ball valves (video)
Ball valve with socket outlet
In the form of a three-way pressure gauge valve, it can also be used with a conventional coupling outlet. Unlike the previous version, the body of such a mechanism is made not of ordinary, but of chrome-plated brass.
A drainage mechanism or a control pressure gauge can be connected to the coupling outlet.
Installation and maintenance
Three-way pressure gauge taps are installed on the pipeline in the same way as any other shut-off mechanisms, including a valve, etc.
Threaded connections are wrapped with fum tape or hemp and screwed to the pipe.
Remember that three-way valves are most often made of brass. Therefore, it is better to tighten the thread manually.
If you do not have enough strength to tighten the joint until the connection is sealed, use a small key. But carry out all the manipulations sensitively so as not to break the thread. For sealing you used fumlent. This type of seal will not tolerate reverse movements or reuse. Therefore, to eliminate the leak, it is worth unscrewing it completely, sealing the joints and screwing it back on.
Why do I need a 3-way pressure gauge valve? Does it always have to be installed? What versions are these devices available in? What malfunctions are typical for them? How to seal threaded connections when installing a valve? Let's try to answer these questions.
Goals
First, let's find out what a three-way manometric valve is needed for.
Its installation has the following goals:
- It allows you to check the measuring device by connecting a test pressure gauge.
Let's clarify: of course, in this case, the tap should not have a drain pipe, but a full threaded outlet or a second device.
The picture shows a three-way valve with a control flange for a pressure gauge 11b38bk.
- The 3-way valve for the pressure gauge makes it possible not only to disconnect the device from the line, but also to relieve the pressure in front of it. This is believed to significantly reduce the likelihood of failure (arrow sticking).
- Finally, it allows you to blow through the outlet to the pressure gauge - to discharge a certain amount of the working medium through it.... When blowing out, any accumulated contamination that can affect the accuracy of the pressure measurement is removed from the tap.
Is it possible to dispense with a conventional straight-through coupling valve? In industrial conditions, where constant pressure control is necessary to comply with the production technology, in pumping stations and on gas pipelines it is not. Incorrect readings can be prohibitively expensive.
In the heating system of a private house or in the elevator unit of an apartment building, pressure gauges are usually connected to an ordinary control valve. Actually, in elevators, a pressure gauge is often installed only for the time of taking control readings: as long as there is free access to technical basements, the problem of equipment theft will remain relevant.
Execution options
How can a three-way valve be arranged for a 1: 2-inch pressure gauge? Here are a few descriptions of the most common designs.
Cork tension
Cork three-way valve with tension sealing 11b18bk is available in the following configurations:
- Two pipe (DN 15) or metric (M20x1.5) threads and a drain hole.
- One pipe thread and one metric thread plus drain port.
- The same, but with a handle (lever or butterfly).
- Two threads (DN 15, M20x1.5 or their combination) and a flange for connecting a control pressure gauge.
The valve is extremely simple in design, but has a couple of significant disadvantages:
- Quite a large switching effort (typical, however, for all plug valves).
- Constant risk of pulling off the plug shank when tightening the nut. Brass is a fairly soft metal, and too much force is not required here.
The principle of operation of a three-way valve for a manometer is simple and straightforward: the T-shaped notch in the rotating plug, when it is turned, is combined with one or two taps.
Accordingly, the following configurations are available in different positions:
- The outlet is plugged, the pressure gauge is connected to the atmosphere through a drain or a flange.
- Pressure is applied to the test valve with a closed drain or flange.
- The branch works as a reset when the pressure gauge is closed.
Ball with drainage
As an example, we will consider a three-way ball valve for an 11B27p pressure gauge. It is interesting in the implementation of drainage. In fact, we have before us an ordinary sleeve valve with an elongated body and a drain hole on one side of the shut-off ball.
Here are the characteristics of the product.
Please note: in such an implementation, a three-way ball valve for a pressure gauge is rather inconvenient for hot water and heating.
The removed drain screw will pour boiling water over your hand.
Ball with coupling outlet
A conventional three-way coupling valve can also be used as a tap under the pressure gauge. An example of such a product is the Valtec VT361N.
This photo shows a three-way valve for a DN15 pressure gauge from Valtec.
The material of the body and the shutter ball of the product is chrome-plated brass; seals are made of Teflon. The maximum operating temperature of the environment is +150 degrees. The durability of the product declared by the manufacturer is noteworthy - at least 20,000 cycles.
Installation
How to seal threaded connections of taps and manometers when installing them with your own hands?
The instruction is, in general, quite standard:
- FUM tape is used on gas lines. Threads are tightened by hand or with a tool, but with minimal effort.
Please note: the FUM tape is fine, but it leaks even with a minimal return stroke.
- For hot and cold water, it is better to use a polymer sealing thread (TangitUnilok and analogues). In its absence, sanitary flax impregnated with any quick-drying paint, sealant or drying oil gives a good result.
Service
The list of valve malfunctions that can be eliminated by yourself is more than small.
- A leak with the plug valve closed indicates insufficient pressure or debris trapped under the plug. Disassemble the valve, wipe the plug and seat, and reassemble. The nut on the shank should only be tightened if the leak persists after cleaning.
- A leak on the ball valve stem indicates a worn out O-ring. If the valve has a stem tightening nut, it can be tightened one or two turns.
If the seal is pressed by the handle and the washer laid under it, with the valve closed, remove them and lay several turns of FUM tape over the seal.
