Bulbless expansion valve with integrated bypass check valve

Abstract

An expansion valve including a valve body having an inlet, an outlet, a main flow passage extending from inlet to outlet, and a metering orifice in the at least one main flow passage. A power element controls movement of a valve member relative to the metering orifice to control flow of operating fluid passing across the metering orifice when the valve is operating in a forward flow expansion mode. The valve body includes an internal bypass flow passage that bypasses the metering orifice, and a bypass check valve is arranged internally of the valve body in the bypass flow passage. The bypass check valve is configured to open at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse bypass mode.

1 . A bulbless-style expansion valve, comprising:
 a valve body having a first inlet, a first outlet, a first main flow passage extending from the first inlet to the first outlet, a metering orifice in the first main flow passage between the first inlet and the first outlet, a second inlet, a second outlet, and a second main flow passage extending from the second inlet to the second outlet, the second main flow passage being separate from the first main flow passage;   a valve member movable in the valve body relative to the metering orifice to control flow of operating fluid passing through the first main flow passage and across the metering orifice as operating fluid flows from the first inlet to the first outlet when the valve is operating in a forward flow expansion mode;   a power element operatively coupled to the valve member and configured to control movement of the valve member at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage from the second inlet to the second outlet when the valve is operating in the forward flow expansion mode;   a bypass flow passage extending internally through the valve body and bypassing the metering orifice; and   a bypass check valve arranged internally of the valve body in the bypass flow passage, the bypass check valve being configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode;   wherein the first outlet of the first main flow passage and an inlet of the bypass flow passage share a common external connection port of the valve body which is configured to connect a conduit of a system incorporating the valve.   
     
     
         2 . The expansion valve according to  claim 1 , wherein the check valve and bypass flow passage are arranged to provide hermetic sealing in which any leakage past the check valve does not escape to an external environment outside of the valve and/or system in which the valve is incorporated. 
     
     
         3 . The expansion valve according to  claim 1 , wherein the bypass check valve is at least partially arranged in-line with the first main flow passage. 
     
     
         4 . (canceled) 
     
     
         5 . The expansion valve according to  claim 1 , wherein the first inlet of the first main flow passage and an outlet of the bypass flow passage share a second common external connection port of the valve body which is configured to connect a second conduit of the system incorporating the valve. 
     
     
         6 . The expansion valve according to  claim 1 ,
 wherein the first main flow passage includes an upstream portion that is upstream of the metering orifice when the valve is operating in the forward flow expansion mode,   wherein the bypass flow passage includes a downstream portion that is downstream of a check valve seat that the bypass check valve engages when closed, and   wherein at least a portion of the upstream portion of the first main flow passage and at least a portion of the downstream portion of the bypass flow passage are a commonly shared passage in the valve body.   
     
     
         7 . The expansion valve according to  claim 1 ,
 wherein the first main flow passage includes a downstream portion this that is downstream of the metering orifice when the valve is operating in the forward flow expansion mode,   wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and   wherein at least a portion of the downstream portion of the first main flow passage and at least a portion of the upstream portion of the bypass flow passage are a commonly shared passage in the valve body.   
     
     
         8 . The expansion valve according to  claim 7 , wherein the bypass flow passage includes a first upstream portion that is shared with a portion of the downstream portion of the first main flow passage, and wherein the bypass flow passage includes a second upstream portion that branches off from the first main flow passage and extends internally within the valve body to the check valve seat. 
     
     
         9 . The expansion valve according to  claim 8 , wherein the bypass check valve is inserted into a vertical bore having an opening in a bottom of the valve body, wherein at least part of the bore is plugged. 
     
     
         10 . The expansion valve according to  claim 1 , wherein the bypass check valve is inserted into a vertical bore having an opening in the second main flow passage. 
     
     
         11 . The expansion valve according to  claim 1 , wherein the bypass check valve is inserted into an inclined bore having an opening in a sidewall of the valve body. 
     
     
         12 . The expansion valve according to  claim 5 , wherein the bypass check valve is inserted into a bore having an opening in a recessed portion of the second common external connection port of the first inlet of the first main flow passage and the outlet of the bypass flow passage. 
     
     
         13 . The expansion valve according to  claim 1 ,
 wherein the first main flow passage includes a downstream portion this is downstream of the metering orifice when the valve is operating in the forward flow expansion mode,   wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and   wherein the upstream portion of the bypass flow passage is fluidly separated from the downstream portion of the first main flow passage.   
     
     
         14 . The expansion valve according to  claim 13 , wherein the bypass flow passage includes a through-opening in the valve body that is downstream of the check valve seat, the through-opening being configured to fluidly connect the upstream portion of the bypass flow passage to a downstream portion of the bypass flow passage when the bypass check valve is activated to open. 
     
     
         15 - 16 . (canceled) 
     
     
         17 . The expansion valve according to  claim 1 , wherein:
 the power element comprises a casing and a flexible diaphragm at least partially within the casing, the flexible diaphragm being operatively coupled to the valve member and being configured to flex at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage when the valve is operating in the forward flow expansion mode; and/or   wherein the metering orifice is formed as an adjustable flow restrictive opening in an annular region between a valve seat in the first main flow passage and an engagement portion of the valve member; and/or   wherein the check valve comprises a stationary plug and a plunger that is movable relative to the plug.   
     
     
         18 - 21 . (canceled) 
     
     
         22 . A bulbless-style expansion valve, comprising:
 a valve body having a first inlet, a first outlet, a first main flow passage extending from the first inlet to the first outlet, a metering orifice in the first main flow passage between the first inlet and the first outlet, a second inlet, a second outlet, and a second main flow passage extending from the second inlet to the second outlet, the second main flow passage being separate from the first main flow passage;   a valve member movable in the valve body relative to the metering orifice to control flow of operating fluid passing through the first main flow passage and across the metering orifice as operating fluid flows from the first inlet to the first outlet when the valve is operating in a forward flow expansion mode;   a power element operatively coupled to the valve member and configured to control movement of the valve member at least partially in response to changes in temperature and pressure of operating fluid passing through the second main flow passage from the second inlet to the second outlet when the valve is operating in the forward flow expansion mode;   a bypass flow passage extending internally through the valve body and bypassing the metering orifice; and   a bypass check valve arranged internally of the valve body in the bypass flow passage, the bypass check valve being configured to activate at least partially in response to operating fluid flowing in a reverse flow bypass mode in which activation of the bypass check valve opens the bypass flow passage to permit operating fluid to bypass the metering orifice in the reverse flow bypass mode;   wherein the first inlet of the first main flow passage and an outlet of the bypass flow passage share a common external connection port of the valve body which is configured to connect a conduit of a system incorporating the valve.   
     
     
         23 . The expansion valve according to  claim 22 , wherein the check valve and bypass flow passage are arranged to provide hermetic sealing in which any leakage past the check valve does not escape to an external environment outside of the valve and/or system in which the valve is incorporated. 
     
     
         24 . The expansion valve according to  claim 22 , wherein the bypass check valve is at least partially arranged in-line with the first main flow passage. 
     
     
         25 . The expansion valve according to  claim 22 ,
 wherein the first main flow passage includes an upstream portion this is upstream of the metering orifice when the valve is operating in the forward flow expansion mode,   wherein the bypass flow passage includes a downstream portion that is downstream of a check valve seat that the bypass check valve engages when closed, and   wherein at least a portion of the upstream portion of the first main flow passage and at least a portion of the downstream portion of the bypass flow passage are a commonly shared passage in the valve body.   
     
     
         26 . The expansion valve according to  claim 22 ,
 wherein the bypass check valve is inserted into a vertical bore having an opening in a bottom of the valve body, wherein at least part of the bore is plugged; or   wherein the bypass check valve is inserted into a vertical bore having an opening in the second main flow passage; or   wherein the bypass check valve is inserted into an inclined bore having an opening in a sidewall of the valve body; or   wherein the bypass check valve is inserted into a bore having an opening in a recessed portion of the common external connection port of the first inlet of the first main flow passage and the outlet of the bypass flow passage.   
     
     
         27 . The expansion valve according to  claim 22 ,
 wherein the first main flow passage includes a downstream portion this is downstream of the metering orifice when the valve is operating in the forward flow expansion mode,   wherein the bypass flow passage includes an upstream portion that is upstream of a check valve seat that the bypass check valve engages when closed, and   wherein the upstream portion of the bypass flow passage is fluidly separated from the downstream portion of the first main flow passage.