Selection type of ball valves for DN100 natural gas pipelines
Thread Content
I checked the process pipeline installation design manual; the ball valves listed there are designed for use with natural gas, and their minimum diameter is 150 – there are no models with a diameter of 100. I need help deciding on the type of ball valve suitable for a 100-inch gas pipeline. Can a model like Q41F-16C be used?
It can be used; it would be best if it had fire and static protection
1) The material of the valve meets the requirements of the medium, preventing corrosion； 2) The pressure rating of the valve shall be no lower than the design pressure of the pipeline ； 3) Design temperature of the pipeline suitable for the valve material ； 4) The connection method of the valve meets the requirements of the pipeline design ； 5) The valve features a fire and static electricity protection structure ； 6) Other factors.
It is best to use a fixed ball valve of type Q47F-16C; it should also be fire and static electricity resistant. When testing the valve, the pressure should not exceed 0.05 MPa
The applicable diameter for this model is 150–600; my gas pipeline has a diameter of 100
They’re all the same; it’s just that the caliber sizes differ
Should the air pressure not exceed 0.05 MPa during valve pressure testing? ? ? Why is such a requirement?
Natural gas is flammable and explosive. Many valves either do not leak under high pressure but do leak under low pressure, or they do not leak at all but require a very high torque; high torque generates static electricity through friction. Natural gas valves have high requirements: the torque must be low, and there must be no leaks at low pressures. That’s why I say that the pressure used during testing these valves should be close to atmospheric pressure, so that they will not malfunction in operation. Of course, **there are no regulations requiring this approach**
The Q41F-16C can achieve a minimum size of DN15; the Process Pipeline Installation Design Manual is a regular book, not a standard. The standard range of sizes is from DN15 to DN800. Note that fixed balls are used for large valves, while floating balls are used for small valves (the boundary is at 6–8 inches). Additionally, depending on the properties of the medium, the valves need to be anti-static and fire-resistant