An air-operated pump is a positive displacement reciprocating pump utilized for the general transfer of liquids, and is driven by means of a compressed gas from an outside source. The compressed gas that’s used within an air-operated pumps is normally just air, and the directional flow of the internal process liquid is produced from suction and discharge check valves. Air-operated pumps are utilized in different industries, including petrochemical and food and beverage facilities, along with wherever else they are needed.

The category of air-operated pumps is usually encompassed by 4 types of pumps that transfer liquids and make use of compressed air as a power source; air-operated diaphragm pumps, bellows pumps, piston pumps and plunger pumps.

An air-operated diaphragm pump contains a diaphragm connected to a reciprocating shaft in which one side of the diaphragm is in contact with the liquid being pumped and the other side is in contact with the compressed air. While various pumps of this model use only one diaphragm, pumps with two diaphragms are better suited for transferring highly abrasive or viscous products.

Alternatively, an air-operated bellows pump contains two bellows connected to a reciprocating shaft which one side of the bellows is in contact with the liquid and the other side is in contact with the compressed air. Air-operated pumps, whether diaphragm or bellows, have an incredibly long pump life if properly manufactured. Their testing covers a wide variety of testing procedures for these two air-operated pump types, including a test to demonstrate mechanical integrity while the pump is in operation, performance test, net positive suction head testing, suction lift testing, hydrostatic testing of pressure-retaining components and noise measurement.