Are there any obvious advantages to connecting check valves and isolation valves directly?
Thread Content
As the title suggests, these are the preliminary PID drawings; in them, almost all check valves are connected directly to the shut-off valves. From an installation perspective, this approach is generally not convenient – such a layout is usually adopted only when space is limited. But since these are just preliminary design drawings and the piping diagrams are not yet available, what obvious advantages does this arrangement have? Or did the designers do it just to save a flange? It shouldn’t be the case.
How can a wafer-type valve be connected directly to a cut-off valve?
Add another flange on the other side of the check valve, which together with the flange of the isolation valve forms a wafer flange
When in an upright position, the operating height can be reduced
Wow, isn’t that unnecessary? Just weld the butterfly valve directly; the result will be pretty much the same with the flanges connected directly
Is your isolation valve a butterfly valve? If so, it’s possible that both the butterfly valve and the check valve are wafer-type, with the two of them being clamped together using a pair of flanges – is that possible?
It’s not that welding butt joints isn’t feasible; the pipe diameter also needs to be taken into consideration. For small pipes that are not part of the main process pipelines, it’s still possible to use this method
What I mean is that in the diagram, the check valves and globe valves are connected directly to each other. So I’m asking: are there any particularly obvious advantages to doing it this way? Is it necessary to do so?
With little material stored, is it not necessary to add a drain valve in the middle?
It is mainly to save space, but condensate drainage measures must be added.