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Title: High vacuum pumping system

Patent ·
OSTI ID:5334579

A high vacuum pumping system for evacuating a vacuum process chambers is described comprising pump means including a diffusion pump for evacuating the chamber, a double-seated poppet valve communicating with the chamber comprising a pair of spaced valve discs movable vertically within the valve between a lower closed position and an upper open position, a dome comprising a confinable volume within the poppet valve above the upper valve disc when in a closed position, refrigerated coils disposed within the dome, a diffusion pump communicating with the chamber through the poppet valve when the lower valve disc thereof is in an open position, means for maintaining equal pressure within the dome and the chamber when the valve discs are in a closed position, means for refrigerating the coils, and other means for moving the valve discs between the open and closed positions.

Assignee:
Pennwalt Corp., Philadelphia, PA
Patent Number(s):
US 4722191
OSTI ID:
5334579
Resource Relation:
Patent File Date: Filed date 21 Jul 1987
Country of Publication:
United States
Language:
English