The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 09, 1996
Filed:
Nov. 14, 1994
Mark Serafin, Apple Valley, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
A piston check valve for use in a system which conveys abrasive materials includes a gland nut which connects the valve to the piping system, a valve body mounted on the gland nut, a valve seat mounted on the valve body, and a piston mounted within the valve body. The piston can translate within the through bore of the valve seat and has a shaft and a head which contacts the first end of the valve seat when the valve is closed. A coil spring is located within the through bore of the valve seat and biases the valve closed. A first O-ring is mounted on the first end of the valve seat and is sufficiently wide to prevent sufficient quantities of chips from becoming lodged within the surface of the inner O-ring to form a hard bridge across the resilient O-ring, allowing erosion of the valve sealing surfaces. The first end of the valve seat has an O-ring groove which receives the O-ring. A second O-ring can be mounted on the first end of the valve seat at the outer periphery of the valve seat.