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:
Aug. 22, 1978
Filed:
Sep. 02, 1976
Fred J Luthe, Marshalltown, IA (US);
Allen E Hays, Marshalltown, IA (US);
Fisher Controls Company, Marshalltown, IA (US);
Abstract
Described herein are fluid flow control valve trims suitable for use in a valve in which high fluid pressure drops are to be sustained without excessive noise generation or cavitation damage to valve members. The valve trim is constructed of two or more annular cages surrounding a central passageway, each outer cage circumferentially engaging the next inner cage. A valve stem carrying a valve plug member is axially movable within the central passageway, the plug member slidingly engaging the radially inward surface of the innermost annular cage. Communicating through the walls of each of the cages are flow-restricting orifices and fluid pressure recovery chambers defining two or more sequential orificial throttling stages. By the use of concentric annular cages a valve trim structure is achieved in which the flow-restricting orifices and pressure recovery chambers may readily be formed having reproducible, predetermined sizes and shapes by conventional machining operations.