Armen75
Chemical
- May 26, 2006
- 27
A hydrocarbon pipe is going through an 800 ft underground tunnel with other hydrocarbon lines. Each line has automatic block valves on either end, just before going into the tunnel, and can therefore be blocked in. The tunnel has foam injectors at either end and leak detectors at every 100 ft.
Are these lines sufficiently protected against overpressure by a simple thermal expansion relief valve (as if they were regular outdoor pipes) or would they require a more rigourous protection (as in fire case) due to their enclosed space.
If fire case is required, is it for the entire 800ft length of the tunnel (which gives a relatively large valve when compared to the size of the pipe) or a portion of the tunnel (in which case, how long?).
I would appreciate any input on this as neither API nor the NFPA discuss tunnels.
Are these lines sufficiently protected against overpressure by a simple thermal expansion relief valve (as if they were regular outdoor pipes) or would they require a more rigourous protection (as in fire case) due to their enclosed space.
If fire case is required, is it for the entire 800ft length of the tunnel (which gives a relatively large valve when compared to the size of the pipe) or a portion of the tunnel (in which case, how long?).
I would appreciate any input on this as neither API nor the NFPA discuss tunnels.