Mech.Seal

[A_123]

question about the function of Throttle bush in Single Seal plan 32 :
1)does it prevent leak or to reduce the leak?

2) standard clearance between throttle bush & sleeve?

3) as you can see in the attached picture PIT Port is not used on the seal just plug, how that will be use to help & prevent the leak?

 

[Aub_Engineer]

1) throttle bushing, I’ve also heard “disaster bushing” decreases a leak but doesn’t prevent one.

2) Standard clearance for fixed bushing is .015” and less for floating bushing .003-.004”

3) extra porting is available for quench or emissions recovery

 

[russcalub]

Throttle bushing is also called safety bushing. This reduces the leakage going to atmospheric side of the seal when the seal failed or when using quench fluid. You can check API 682 for the specific clearance per size, type and temperature.