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:
May. 14, 1985
Filed:
Jan. 12, 1984
Brett A Babbitt, Katy, TX (US);
Tri C Le, Missouri City, TX (US);
Joy Manufacturing Company, Pittsburgh, PA (US);
Abstract
A pressure energized mechanically preloaded packing assembly (48, 68) of a high pressure gate valve (10). The packing assemblies are positioned in an annular space about the valve stems (36, 64) for sealing between the valve stems and bonnet (38) or valve body (12). The packing assemblies include an energizer ring (78) which is positioned within the annular space having an outwardly facing precision cut frusto-conical end surface (82) relative to the flow passage (16, 18) of the valve. A plurality of Belleville springs or spring washers (98) with a generally frusto-conical shape are positioned adjacent and in concave relation to the outer end (82) of the energizer ring. The cone angle of the spring washers are smaller than the cone angle of the energizer ring. The packing assembly further includes at least one packing ring set positioned outside the spring washers (106, 108) which includes a stack of plastic packing elements (110) which are sandwiched between a pair of retainer rings (112, 114). A packing gland nut (118) is disposed in contiguous relation to the packing ring set and is externally threaded for accommodating its connection with the valve body whereby the gland nut is axially adjustable to apply axial pressure on the packing ring set and spring washers. The spring washers (98) are compressed until their cone angle matches the cone angle of the energizer ring (78) such that the spring washers exert a predetermined preload onto the packing ring set to provide a low pressure seal between the stem and valve body.