Thermal expansion valve with internal by-pass and check valve

US5251459A · kind A · utility

Assignee

• Emerson Electric Co. · US

Inventors

• Thomas Grass · Neukirchen, DE
• Robert W. Haul · Chesterfield, US

Key dates

• Filing date: Mar 31, 1992
• Grant date: Oct 12, 1993
• Expiry date: Mar 31, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/7927
• WIPO field: Thermal processes and apparatus
• WIPO sector: Mechanical engineering

Abstract

A reversible flow thermal expansion valve for use in a heat system is disclosed wherein the thermal expansion valve includes a valve body having a flowpath therethrough with an inlet and outlet, an expansion port within the flowpath, and an expansion valve to open and close the expansion port. An internal by-pass flow path by-passes the expansion port for reverse flow through the expansion valve. A check valve in the by-pass flow path prevents refrigerant from by-passing the expansion port during regular, forward flow through the expansion valve. The check valve has a spring to bias the check valve normally closed, and a bypass port communicating between a check valve guide path chamber and a check valve outlet in order to relieve pressure in the guide path chamber and increase the flow rate through the check valve.