API 676
API 676
(OP)
We are using API 676 vane pump for the fuel service . As per API 676, there is no insistence of the External pressure relief valve but asked to have a safety system like PCV or pressure limiting valve.. Vendors are giving internal relief valve inside the pump. How reliable is these internal relief valves? or should we insist for external pressure relief valve in addition to internal relief valve. This pump is installed in an independent package and there is no process system pressure acts on the package. This package supplies fuel to the helicopters in an offshore platform .





RE: API 676
Therefore there must some other instrumentation to shut down the pump fairy quickly.
RE: API 676
I would insist of a temperature alarm / shutdown and also a high and HH pressure switch to shut down the system in the event the internal relief failed to operate correctly as these pumps, as I'm sure you know, can generate high presures very quickly if the phyiscal pressure relief fails to operate or becomes clogged. Most of the time though the issue is that the relief valve passes when it shouldn't and results in poor delivery pressure / flow. This is when ability to test and maintain the valve becomes important.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: API 676
I cannot imagine a system passing ABS, USCG, or any other of the regulating agencies offshore without a mandatory external relief valve. The vendor can supply the relief valve, but really it should be sized/selected under your eyes since it will be protecting your system.
RE: API 676
But it is recommended to use another in the system , too.