Patent ID: 6210107
Filing Date: 2001-04-03
Classification: F16J

Abstract:
A seal combination for sealing between a housing and a relatively rotating shaft extending through a bore in the housing, the housing defining a chamber for containing a process fluid under high pressure, said seal combination comprising:(a) an outboard barrier seal means at least a portion of which is mounted on said housing;(b) an inboard barrier seal means at least a portion of which is mounted on said housing and positioned axially of said outboard barrier seal means, said inboard and outboard barrier seal means and said housing defining a buffer fluid chamber;(c) pumping means carried by said inboard barrier seal means for pumping a buffer fluid from said buffer fluid chamber towards the inboard process fluid pressure side of said inboard barrier seal means in opposition to fluid leakage from the inboard barrier seal means side;(d) a buffer fluid reservoir located externally of said housing and in fluid communication with said buffer chamber so as to supply buffer fluid to said buffer chamber;(e) circulation means separate and removed from said pumping means for causing the buffer fluid to circulate from said reservoir, through said buffer chamber and to return to said reservoir; and(f) a means for pressurizing said buffer fluid in said reservoir separate and removed from said pumping means.