Used to detect and monitor leakage of the inboard seal, these seal support systems can detect liquid leakage (API Plans 65 and 75) or gas leakage (API Plan 76), or a mixture of gas and liquid leakage (API Plan 75). A PD 75 (API Plan 75) collection system is used to monitor inner seal performance (level and pressure), where a dry-running secondary containment seal is applied to a process fluid that will condense at lower temperature or is always in a liquid state.