A hydraulic gas pump is a type of pump that uses gas as the power source to drive a hydraulic system. It consists of a gas engine, a hydraulic pump, a reservoir, a relief valve, and a directional control valve. How do hydraulic gas pumps work? When a hydraulic pump operates, it creates a vacuum at the pump inlet, which forces liquid from the reservoir into the inlet line to the pump and by mechanical action delivers this liquid to the pump outlet and forces it into the hydraulic system. Specification: Specially design for wooden fittings, Different forces for the same dimensions, High Durability, Long life, Oil incorporated for cushioning & seal lubrication different fixing end-connection. Application: For easy opening of all type of cabinet doors.