Sorry for the lack of information. Lets call Air Valve #1 the upsteam valve and Air Valve #2 the downstream valve. Here is the sequence of operation, Both Air Valves #1 & #2 are opened. Pump is turned on to fill the line. After a mass flow meter (after air valve #2) detects flow into the tank...
The overpressure is happening just after the first valve shuts. It makes sense that air is trapped in the leg just before the relief valve. Do you believe this is the cause of the problem? Are there any rules of thumb that you know regarding the installation of PRVs? Attached is a quick...
I thought about that, I will have to check that on Monday. These are all air operated jamesbury valves. I may be able to exercise each one to see how fast they are closing.
Thanks for the help.
I checked the sequence of operation. It is in fact operating as you suggested. Both valves are open and the pump begins transferring to clear the air in the line. Then the downstream valve shuts followed by the upstream valve.
I do have another hypothesis. On the relief...
This is an acid transfer line which transfer from building to building. Since they are transferring outside during the winter, they blow the lines out with air. This particular acid begins to thicken at 50 deg F and fully freezes at 32 deg F. Even though the line is steam traced, the operators...
I am at a plant working on a few product transfer lines. I transfer from building to building crossing out side containment areas. As part of an environmental project, I had automatic valves installed at each building. Before the operator transfers, he must test the line for leaks by charging it...
