Where, how and when i must use double check valves (two check valves in serie)?
I ask it because we are using this configuration in several questionable points. Like liquid level control of equipments, connections in headers and stand by equipments.
In other cases we are using doble check valves at stand by equipment to prevent back flow from discharge common line.
despite using SDV valve to isolate.
More details.
This fluid is condensed and, in some cases, oily water and/or oil is continuously drained from equipment with high pressure to equipment with low pressure, however, when the first is depressurized, the second becomes at a higher pressure and reverse flow can occur.
Sorry for a few details.
Normally these scenarios are in compression system where we drain second stage scrubber to first stage scrubber, for exemple. Second stage is 30 bar and first stage is 10 bar. Therefore, when we stop the system and the second stage depressurizes with the first stage...
At my workplace, we have been installing them in various locations, but it seems we have lost our way a bit.
We are putting doble check valves in drainage points to prevent backflow when the vessel pressure drops below the drainage system’s pressure.
I would like to know where exactly should...
