Including pump cap and pump seat; The pump cap is the part of the pump head, including the wire connection chamber, wire connection pipe assy, capacitor chamber, exhaust thread plug, check valve, air components, exhaust, and joint stress test, pipeline leak detection device (optional). The pump seat is the remaining part of the pump, including the pipeline entrance, wire connecting inlet, oil outlet, and tubing support line. Automatic exhaust gas eliminator, remove easily, maintain easily, more safety, equipped with manual relief valve.