API PLAN 75
Leakage of condensate from inboard seal of a dual
containment seal is directed to a liquid collector.
In Piping Plan 75 there is a containment seal
chamber leakage collection system for condensing or
mixed phase leakage. This plan is used when pumped
fluid condenses at ambient temperatures.
Collection can be redirected to process fluid by
using separate pumping device.
The pressure transmitter in Piping Plan 75 will
track the pressure in the vapor collection system.
In normal operation, the pressure in the containment
seal chamber can be as high as the vapor collection
system pressure plus the check valve cracking
pressure (if present). Pressures greater than this
may indicate excessive leakage past the inner seal.