Air operated double diaphragm pump with differentiated check valve sizing

Abstract

In one example, a displacement pump has a suction side including a suction check valve, and a discharge side including a discharge check valve. The discharge side and suction side are each configured for selective fluid communication with each other, and the suction check valve defines a flow area that is relatively larger than a flow area defined by the discharge check valve.

What is claimed is: 
     
         1 . A displacement pump, comprising:
 a suction side including a suction check valve; and   a discharge side including a discharge check valve, the discharge side and suction side being configured for selective fluid communication with each other, and the suction check valve defining a flow area that is relatively larger than a flow area defined by the discharge check valve.   
     
     
         2 . The displacement pump as recited in  claim 1 , wherein the displacement pump includes a displaceable element, and operation of the pump is effected by alternating movements of the displaceable element. 
     
     
         3 . The displacement pump as recited in  claim 1 , wherein the displacement pump is an air-operated displacement pump. 
     
     
         4 . The displacement pump as recited in  claim 1 , wherein the displacement pump is a diaphragm pump. 
     
     
         5 . The displacement pump as recited in  claim 1 , wherein the displacement pump is a bellows pump. 
     
     
         6 . The displacement pump as recited in  claim 1 , wherein the displacement pump is an air-operated double diaphragm (AODD) pump. 
     
     
         7 . The displacement pump as recited in  claim 1 , wherein a flow area of the suction side is relatively larger than a flow area of the discharge side. 
     
     
         8 . The displacement pump as recited in  claim 1 , wherein the suction check valve includes a suction check element, and the discharge check valve includes a discharge check element, and the discharge check element has an outside diameter that is smaller than an outside diameter of the suction check element. 
     
     
         9 . The displacement pump as recited in  claim 8 , wherein one or both of the suction check element and the discharge check element is a ball. 
     
     
         10 . A diaphragm pump, comprising:
 a suction side comprising an inlet bore configured for selective fluid communication with first and second suction check bores, each of the suction check bores housing a respective suction check ball, and each suction check bore and suction check ball forming part of a suction check valve; and   a discharge side comprising an outlet bore configured for selective fluid communication with first and second discharge check bores, each of the discharge check bores housing a respective discharge check ball, and each discharge check bore and discharge check ball forming part of a discharge check valve,   wherein the inlet bore has a larger flow area than a flow area of the outlet bore, the first and second suction check bores each have a relatively larger flow area than respective flow areas of the first and second discharge check bores, and the suction check balls are relatively larger in diameter than the discharge check balls.   
     
     
         11 . The diaphragm pump as recited in  claim 10 , further comprising:
 a pump body;   a pump head connected to the pump body; and   first and second diaphragms disposed between the pump head and the pump body, and one side of one of the first and second diaphragms is arranged for fluid communication with one or the other of the suction side or the discharge side.   
     
     
         12 . The diaphragm pump as recited in  claim 11 , wherein one or more of the following components substantially comprises plastic: the pump body, the pump head, the first diaphragm, the second diaphragm, the suction check valve, and the discharge check valve. 
     
     
         13 . The diaphragm pump as recited in  claim 11 , further comprising a union nut that releasably secures the pump head to the pump body. 
     
     
         14 . The diaphragm pump as recited in  claim 10 , wherein the diaphragm pump is an air-operated double diaphragm (AODD) pump.