Why should the pipe under the pressure gauge make a bend?
After the production of equipment and piping, often need to strength and leakage test. Pressure gauge will be used for pressure testing, I do not know if you have noticed, the pressure gauge and equipment, piping between the connection is bent. Why pressure gauge below the pipe to make a bend? The following is the name and role of the bend.
The bend below the pressure gauge is called the pressure gauge buffer pipe, the construction staff customarily called the pressure gauge pipe bend.
It has two forms, one is a ring bend, the other is a U-shaped bend.
The latter name is more intuitive and apt. This seemingly insignificant design actually serves a great purpose. It is a design in line with polytechnics and has a role that should not be underestimated, including the following two aspects. On the one hand, it is to protect the pressure gauge to prevent it from being damaged by high pressure, and on the other hand, it is to ensure the accuracy of the pressure gauge measurement value.
It is understood that in foreign countries with this pressure gauge bend tube principle is the same pressure relief hole, with the help of these simple design, can achieve better protection of the pressure gauge, to ensure that the pressure gauge can work properly. Pressure buffer tube, as the name implies, can buffer pressure. The substance in the pipeline transportation can be liquid or gas, and both of them are with fluid pressure. When the pressure of the medium in the pipeline is too large or the pressure fluctuation of the transported material is large, without this pressure buffer tube, it will act directly on the pressure gauge.
When the fluctuation is slight, it only makes the pressure gauge reading deviation, so that the display is not accurate; when serious, it will directly damage the pressure gauge, for the subsequent work to bring maintenance and replacement of the trouble. Pressure gauge is generally used in a variety of manufacturing industries, such as hot water heating supply systems, oil pipeline transportation, thermal pipeline network, automotive maintenance and other aspects, it can be seen that its use is still very extensive. If the pressure gauge failure, it will bring immeasurable huge losses and safety hazards.
The role played by the pressure gauge bend is to protect the pressure gauge, to prevent some controllable factors from causing damage to it, can be said to be the crystallization of human wisdom.
Today collated the pressure gauge related content for your reference.
1. control valve and pressure gauge should be installed on the suction pipe of the fire pump; control valve, check valve and pressure gauge should be installed on the discharge pipe.
2. A silent check valve, control valve and pressure gauge should be installed on the discharge pipe of fire pump; pressure gauge and pressure switch should also be installed on the total discharge pipe of the system; a buffer device should be added when installing the pressure gauge. Pressure gauge and buffer device should be installed between the plug; pressure gauge range in the absence of design requirements, should be 2 times the working pressure of the system ~ 2.5 times.
3. Fire pump test pressure gauge should not be less than 2; accuracy should not be less than 1.5 level, the range should be 1.5 times ~ 2 times the test pressure value.
4 fire pump suction pipe and discharge pipe should be set on the pressure gauge, and should comply with the following provisions:
(1) the maximum range of the pressure gauge of the fire pump discharge pipe should not be less than 2 times its design working pressure, and should not be less than 1.60MPa.
(2) fire pump suction pipe should be set up vacuum table, pressure table or vacuum pressure table, the maximum range of the pressure table should be determined according to the specific conditions of the project, but should not be less than 0.70MPa, the maximum range of the vacuum table should be -0.10MPa.
(3) the diameter of the pressure gauge should not be less than 100mm, should use the diameter of not less than 6mm pipe and fire pump import and export pipe connection, and should set the shut-off valve.
5. Rain shower alarm valve import and export should be set pressure gauge; pressure gauge should be installed in the alarm valve on the location of easy to observe.
6 gas fire extinguishing system storage container or container valve, should be set up on the safety relief device and pressure table.
7 automatic sprinkler system test pressure gauge should not be less than 2; accuracy should not be less than 1.5 levels, the range should be 1.5 times the test pressure value ~ 2.0 times.
8. The end of the water test device should be a water test valve, pressure gauge and water test joints. The flow coefficient of the water test fitting outlet should be equal to the minimum flow coefficient sprinkler nozzle on the same floor or within the fire protection zone. The end of the water test device water, should take the orifice out of the flow of the way to discharge into the drainage pipe, drainage riser should be set to stretch the top ventilation pipe, and the diameter of the pipe should not be less than 75mm.