How to Avoid AODD Pump Failures

Air Operated Double Diaphragm (AODD) pumps are robust and adaptable instruments that are extensively employed in many industrial domains for the transfer of viscous liquids or those containing solid components. They have emerged as one of the go-to options for a variety of transfer applications because of their simple but effective design and simplicity of usage. They may, however, experience some problems during installation and use, just like any other mechanical equipment. Being aware of frequent issues and their related remedies is essential to ensuring optimal performance and maximising the lifespan of a double diaphragm pump. 

Utilise a Regulator For Optimal Pressure

A steady and regulated air pressure is necessary for AODD pumps to operate as intended. The diaphragm is kept from being overly stressed through the installation of an air pressure regulator to help maintain the proper pressure range. Because of the increased wear and tear caused by operating at extremely high pressures, diaphragm failure might occur prematurely. Installing a regulator and maintaining it within the advised pressure range will guarantee the pump's effective operation and prolong the diaphragm's life.

Inspect For Muffler Icings And Restrictions

Since diaphragm pumps can produce loud noises while operating at maximum capacity, installing a muffler is advised. Compressed air is necessary for the AODD air motor to function. Rapid temperature variations happen as the compressed air enters the air valve and travels through the pump centre portion before exhausting through the muffler. The air temperature at the muffler exhaust is below freezing, which might lead to icing problems, which are frequent in humid areas. Pump efficiency can be negatively impacted by icing-related problems, which can be identified by irregular pump operation, high moisture content in the incoming air, or visible frost outside the muffler. Here are a few tips to steer clear of these problems:

• Reduce the pump's air pressure.
• To run at lower rates (i.e., lower air pressure), increase the pump's size.
• Use an exhaust port tube to send exhaust air to a distant place.
• Use a drain for collecting condensation and install an air line filter and a water catcher.
• To get the exhaust air temperature above freezing, use an air line heater.
• Use an air compressor dryer to change the pressure dew point temperature.

Torque Settings

Strong and frequent stroke impacts are known to dislodge bolts in AODD pumps, which lowers pump pressure over time. Periodically retightening the bolts ensures that the sealing surfaces remain sealed. Since moulded plastic is softer and more prone to warping from internal tension, it is advised to reinforce plastic pumps with iron plates.

Utilize a Liquid Level Controller

Another add-on that can give AODD pumps a safe and affordable method of control (off/on/on functionality) is a liquid-level controller. The most common applications for liquid-level controllers are in chemical and water sump systems. They operate on a simple mechanic: As the liquid level rises and falls, a pneumatic float switch switches on and off the air to the pump. Liquid-level controllers and air filters/regulators extend the life of diaphragms and save energy costs. Most significantly, air pressure control can stop early failures that could result in product loss, expensive cleanup, and unscheduled downtime.

Opt For One-Piece Diaphragms

One-piece diaphragms provide notable mitigation of the risk of failure. Considering that one-piece diaphragms lack the joint or junction which two-piece diaphragms do, they are less likely to leak or rupture. They provide increased integrity and durability, particularly in applications where the pump handles abrasive fluids or is subjected to repeated cycles. 

Chemical Compatibility

All parts of the diaphragm pump that come into contact with the fluid, including balls and seats, need to be resistant to chemical damage and compatible with the diaphragms. When the diaphragm exhibits bubbling, cracking, or discoloration, it is an indication of a chemical attack and premature diaphragm failure. To avoid this problem, it is essential to carefully examine the application and choose materials that are compatible with chemicals. The chemical compatibility guide provided by the diaphragm pump manufacturer or contacting the manufacturer for technical assistance can be used to choose compatible materials. 

Avoiding Leakage Due To Defective Gaskets

A common tool for moving liquids between different industrial sectors is the double diaphragm pump. Leakage, however, is a frequent issue that these pumps may encounter and can result in a number of unfavourable outcomes. Defective gasket leakage can lower the pump's performance and efficiency, resulting in liquid waste and possible environmental harm. It is crucial to make sure that all gaskets are correctly tightened in accordance with the manufacturer's instructions during membrane pump setup and upkeep. To guarantee a tight seal, gaskets must be placed and fitted correctly. Leaks may originate from damaged or loose gaskets. One can significantly decrease the possibility of unexpected leaks by utilising PTFE gaskets that are placed correctly and replacing them on a regular basis. An effective pump that doesn't leak will ensure consistent transfer and minimise liquid waste.

Check Valve Failure

AODD pumps often use check valves in the ball form. The most common cause of these check valve failures is foreign objects getting in the way of the ball and seat, which prevents the valve from closing tightly enough to stop leaks. This likelihood will be decreased by using a strainer. Additionally, clearing the dirt from the check valves is generally achieved by cleaning the pump when you believe something is stuck. Leak routes are also caused by wear on the ball and seat. This wear may be the result of poorly chosen material for balls or seats, or it may be caused by sharp particles in the liquid.

Conclusion

AODD pumps are the go-to option in transfer applications because of their dependability. They are inexpensive and simple to use owing to their simple layout. End users need to install and use AODD pumps appropriately in order to get optimal performance. When properly maintained and cared for, pumps from top AODD pump suppliers, such as AYTC, may offer consistent and efficient fluid transmission for many years.

Ali Yaqoob Trading Co. (AYTC), an ISO 9001-certified business with its headquarters in Dubai, is a global leader in the distribution and repair of liquid, vapour, and gas handling equipment. Since 1986, they have served the chemical, petrochemical, oil, liquefied gas, tank truck, transport, liquid terminals, maritime, aviation, industrial, and military sectors with top-notch products and custom solutions. They offer polypropylene, PVDF or conductive acetal casing for their all-purpose plastic AODD pumps and aluminium, cast iron, stainless steel or alloy c for their metal casing pumps. Polypropylene can be applied to a broad range of chemical applications. PVDF is more abrasion and temperature-resistant than polypropylene, and it has superior chemical endurance against both acids and bases.