What Are Air-Operated Pumps?
An air-operated pump is a positive-displacement reciprocating pump used for the general transfer of liquids, and it is driven by means of a compressed gas from an outside source. The compressed gas that is used within air-operated pumps is usually just air, and the directional flow of the internal process liquid is produced from suction and discharge check valves. These types of pumps are used in facilities of all sizes in a plethora of different industries, including petrochemical and food and beverage facilities, along with wherever else they are needed.
Types of Air-Operated Pumps
The category of air-operated pumps is commonly encompassed by four 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.
Air-Operated Diaphragm Pumps
An air-operated diaphragm pump contains a diaphragm connected to a reciprocating shaft. 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 many pumps of this model use only one diaphragm, ones with two diaphragms are better suited for transferring highly abrasive or viscous products. An example of an air-operated double diaphragm pump configuration can be seen in the figure below:
Air-Operated Bellows Pump
Alternatively, an air-operated bellows pump contains two bellows connected to a reciprocating shaft. One side of the bellows is in contact with the liquid and the other side is in contact with the compressed air. The figure below demonstrates a typical air-operated bellows pump:
Air-Operated Pump Standards
The above figures are from ANSI/HI 10.1-10.5: Air-Operated Pumps for Nomenclature, Definitions, Application, and Operation, the standard for defining important terms related to air-operated diaphragm pumps and bellows pumps. It covers air-operated diaphragm pumps and bellows pumps but not piston pumps and plunger pumps. The nomenclature covered within this standard serves as a common language for thosewho deal with the equipment, and the terms associated with their components are intended to foster a standard understanding of them and their purpose.
Air-operated pumps, whether diaphragm or bellows, can last an incredibly long pump life if they are properly manufactured. ANSI/HI 10.6-2016 – Air-Operated Pump Tests covers a 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.
Ultimately, the tests covered in ANSI/HI 10.6-2016 – Air-Operated Pump Tests allow for uniform, reliable testing of the pumps so that they can efficiently pump fluid.
Both of these documents were written and published by the Hydraulic Institute, an ANSI-accredited standards-developing organization. The Hydraulics Institute seeks to promote the advancement of the pump manufacturing industry and further the interests of the public by developing standards, advocating for the industry, and educating the marketplace.
Hydraulic Institute Standards are available on the ANSI Webstore.
1. Hydraulic Institute, Inc., ANSI/HI 10.6-2016 – Air-Operated Pump Tests (Parsippany: HI, 2016), 1.
2. Hydraulic Institute, Inc., ANSI/HI 10.6-2016 – Air-Operated Pump Tests (Parsippany: HI, 2016), 2.