Leakage control
Periodic recording of the effective leakage rate provides information about the condition of the mechanical seal and about the system being sealed. If after thousands of operating hours of near constancy the recordings show an initially gradual but then accelerating rise in the leakage rate, the mechanical seal is approaching the end of its working life. Plans can and must be made for its replacement. Violent fluctuations of the leakage rate are either the result of frequent changes of operating conditions or an indication of malfunctions. At all events, it is sensible to establish the causes of violent fluctuations. The following methods of leakage control have proven successful on the practical level: For double mechanical seals with buffer fluid circuit: recording of refill quantities and intervals. Also recording the leakage rate of the mechanical seal on the product or atmosphere side enables the condition of both sides of the mechanical seal to be assessed.		For single mechanical seals with circulating liquid quench: determination of the refill or overflow quantities per unit of time. For single mechanical seals with selective leakage collection and removal: installation of a leakage collection vessel, with periodic manual or automatic determination of the leakage rate (leakage detector). For single or double agitator seals for top drives: discharge of the leakage (collected by a leakage trap) via a leakage sight glass and determination of leakage rate.