Actuator valve of an air operated double diaphragm pump

An air operated double diaphragm pump (100) comprising:

• an inlet manifold (102) having an inlet port (104), the inlet manifold (102) is configured to receive a fluid via the inlet port (104);
• an outlet manifold (106) having an outlet port (108), the outlet manifold (106) is configured to exhaust the fluid via the outlet port (108);
• two chambers (112a, 112b);
• a central shaft (124) disposed between the two chambers (112a, 112b), the central shaft (124) is configured to reciprocate between the two chambers (112a, 112b);
• a diaphragm (130a, 130b) attached at each end of the central shaft (124), the diaphragm (130a, 130b) at each end is configured to divide the respective chamber (112a, 112b) into an air chamber (132a, 132) and a fluid chamber (134a, 134b);
• an actuator valve (136), the actuator valve (136) comprising:
• a valve housing (138);
• an inlet (142) for receiving air from an external source;
• a first set of ports (144a, 144b) for exchanging the air with each of the air chambers (132a, 132b);
• a second set of ports (146a, 146b) for exhausting the air received from each of the air chambers (132a, 132b) into the atmosphere;
• a valve piston (148) accommodated within the valve housing (148), the valve piston (148) is configured to reciprocally slide within the valve housing (138);
• and an end plate (156a, 156b) arranged at each end of the valve housing (138) for limiting the movement of the valve piston (148), wherein the valve piston (148) has a bore (152) at one end, and the valve piston (148) further comprises a secondary bore (154a, 154b) at each end in order to pressurize a space between each end of the valve piston (148) and the respective end plates (156a, 156b), to prevent stalling of the valve piston (148) and rotary motion of the valve piston (148), wherein the end plate (156a) has a boss (158) at the corresponding end, and wherein the boss (158) of the end plate (156a) is arranged to mate with the bore (152) of the valve piston (148), and the boss (152) of the end plate (156a) and the bore (152) of the valve piston (148) form a pressure tight seal while mating, wherein the boss (158) has a circular groove (162) at the distal end, and wherein a sealing member (160) is accommodated within the circular groove (162) and the sealing member (160) is an O-ring.