Hello everyone,
We have 03 No. pump-around (Naphtha/Kero/Gas oil) at our CDU distillation column, each provided with dedicated circulation pumps (for removal of PA heat) and single isolation valves (gate type) at pump suction. Whenever these pumps are switched for maintenance purposes, severe problem of suction valve passing is faced. Rust material has been observed at the valve seat which doesn't allow proper disc settling on the valve seat and hence the passing problem. Since, pump is operating at high temperatures with hydrocarbon service, there is obvious fire hazard if pump is taken out of services with the passing.
What could be the possible solutions?
1) How effective block & bleed valves will be in this case (Due to space constraints, this option is not very endorsing in our case)
2) Is there any special valve available for such services with proven experience?
3) Can we provide flushing stream from downstream of pump to upstream of isolation valve for valve seat flushing?
Any response will be highly appreciated. Thanks
Edited by Jaguar_011, 13 April 2021 - 10:44 PM.