Independant Safety Valve

[ruttie]

We have four 200mm plug valves that are used for preventing over-speed of a turbine. If these valves fail we need a redundant system of independant valves.

According to our Reliabilty department this independant system should not be a typical valve arrangement(i.e. plug-, butterfly-,ball- or gate valve with a pneumatic, hydraulic or electric actuator. The reason being that this doen not provide the neccessary independancy.

Are there any "valve systems" available that is of different design than the standard type of valves.

Typical operating conditions:
1. dP = 60 Bar
2. Temp = 100 C
3. Opening time = 200 ms
4. Medium = Helium
5. Force required = 25000 kg
6. Valve size = 200mm

Thank you

Ruttie

 

[RobV]

If this is the second layer of protection you would should look into valves that are used in High Integrity Pressure Protection system. Valves used in HIPPS should meet design standards like the German DIN 3381 and /or IEC 61508/61511.

The company Mokveld supply many valves installed in HIPPS application with good supported reliability data. The valve design itself in based on an 'axial' flow principle and doesn't even look like any other valve. It may just be what you'd be looking at.

Check there website :

http://www.mokveld.com