May I ask if internal thread connections can be used for safety valves on Class 2 containers?
Thread Content
Previously, a type 2 container was designed; the person who reviewed the design said that safety valve connections on type 2 containers cannot use internal thread interfaces. I’m not sure if this is indeed the case (0.9 MPa, hydrogen storage tank)
I think that when the pressure is high, ordinary pipe threads of type G cannot be used; cone-shaped pipe threads can be employed within certain pressure ranges. However, since hydrogen is a flammable and explosive medium, necked butt-welded flanges should be used as much as possible.
Thank you for your reply. The container has now been manufactured, but the drain valves and safety valves present difficulties in terms of installation. All of them use necked flanges, and their sealing surfaces are uneven; whereas the accompanying safety valves and drain valves have flat flanges. What should be done in this situation? Thank you. Additionally, there is a hydrogen storage tank operating at atmospheric pressure, with a maximum pressure of 0.08 MPa. According to the standards, it is required that manholes be fitted with necked flanges – is this indeed the case? Thank you
For flammable and explosive substances, threaded connections are best avoided.
Reply to 3# dewaiyang: Since hydrogen is a flammable and explosive substance, any leakage poses a great risk； 1. Therefore, the sealing should adopt a male-female or tenon-socket design. Therefore, the valve has to be replaced. 2. Although it is a pressure vessel at normal pressure, the sealing should use a male-female or tenon-socket design; standard manholes only have male-female or tenon-socket designs when equipped with a neck flange.
If there is a design basis, follow that design~
Why not? I remember a piece of equipment imported from Japan many years ago, which used a pressure of 20 MPa and threaded connections, and it worked without any problems at all during use.
This post was last edited by ssun*nhong on 2011-7-18 17:07. Safety valves come in inlet and outlet types. The inlet is generally connected by flanges or welding, while the outlet can be connected by flanges, welding, or threading ； The selection is related to the medium’s leakage level.