Fire safe/renewable seat/ 3

[B.L.Smith]

Hi

I have some questions?
1- For which type of valves, fire safe is meaningless?
2- Which type of valves can have renewable seat?
3- which type of valves do not have soft seat?

 

[bcd]

Hi

I have some answers.

1. Fire safe is meaningless for valves that do not contain flammable media. For example, water valves. Or it can be said that fire safe is meaningless for valves that do not pass a fire test.
2. Any valve that can be taken apart and the seats removed and replaced is a valve that has renewable seats.
3. Valve that have seats made from metal or ceramic only are not soft seats. Conversely, any valve that has plastic or rubber for the sealing part are soft seated. Note that valve with metal seats that use rubber o-rings or graphite, or polymers to block leakage around the OD of the seat are still considered metal seated valve. They are soft-seated when the primary sealing between the seat and obturator are plastic or rubber.

 

[B.L.Smith]

Thank u bcd, but the mean of "which type" is type of valve such as ball, globe, check, plug, butterfly and gate valve.

 

[bcd]

Your question has no specific answer. All the types of valves you mention may or may not be fire safe, renewable seats, or may not have soft seats. The answer depends upon the details of the valve construction. For example, a rubber line concentric type butterfly valve cannot pass a fire test. But butterfly valves with offset disc can pass a fire test when it has a seat designed to do so. Other types of butterfly valves are metal seated and the seats may or may not be renewable. It depends upon how the valve is designed and constructed.