If there’s one thing a plant maintenance manager can’t tolerate, it’s downtime.
Production stoppages mean lost revenue. To avoid downtime, plant personnel must keep the plant’s systems and machinery running smoothly and handle all planned maintenance, upgrades and emergency repairs as quickly as possible.
Fortunately, one of the common pieces of equipment in plants—Air-operated double-diaphragm (AODD) pumps—is designed to make maintenance simple and cost-effective. Still, an experienced plant maintenance manager will look for ways to optimize AODD pump performance to keep downtime to a minimum and improve pump efficiency.
Before steps to increase reliability can be taken, it’s best to know the basic components of an AODD pump:
In this AODD pump diagram, A and B are the diaphragms, 1–4 are the ball valves and I and O the inlet and outlet ports. An AODD pump uses compressed air to power the repeated back-and-forth motion of the diaphragms, which are mounted on C, a connecting rod. This continuous motion forces liquid out of one chamber for discharge while the other chamber fills with liquid.
A pump's location within the system is critical to its performance and longevity. This is because AODD pumps can be used in three main ways:
AODD pump material selection will increase the reliability, performance and life of a pump, decreasing downtime and increasing profitability. However, these fluid characteristics must be considered before choosing a pump's material:
Understanding the pump's external environment is also critical to an AODD pump's longevity. For example, if its environment contains fumes, the entire pump, including the air side, must be compatible. If the pump will be exposed to UV light from the sun, plastic pumps may not be ideal. And, if you're pumping abrasive material, you may want to choose harder casting and seat materials. In every case, you should consult the pump's manufacturer for details.
According to the Hydraulic Institute, pumping systems account for over 40% of industrial energy use. Energy saved equals dollars saved when it comes to powering pumps.
AODD pump up-sizing is one strategy to reduce AODD pump energy consumption. When you increase the size of the pump for the same desired flow, it increases the pump's efficiency—ensuring the maximum volume of liquid is pumped per amount of compressed air consumed.
In other words, if a pump is running to the far right hand of the curve (i.e., the pump is running flat out) to produce the desired flow rate, going up one pump size can allow you to shift the performance point to the left on the curve. This means the pump will cycle less and you'll reduce energy consumption and extend pump longevity while getting the same desired output.
Displacement per stroke (or cycle) is also important to note, as there's a direct correlation in pump longevity and efficiency. In many cases, choosing a pump with greater displacement per stroke will reduce wear on the unit.
Using a larger unit can also reduce wear when pumping abrasive liquids, such as ceramic slip. By upsizing the AODD pump and running it slower, you reduce fluid velocity, which, in turn, reduces abrasive wear.
Air filters/regulators play a crucial role in the performance of AODD pumps by preventing wet and contaminated air from entering the pump. When outside air is drawn into the compressor, it naturally contains moisture that can freeze when it expands inside the pump. The resulting ice can cause the pump to stall. Air filters/regulators protect the air valve of the pump by removing solids and liquid contaminants from the air lines while providing additional precise pump control.
The air filter/regulator can also help you start the pump in a gradual "soft" manner, which creates less stress on the pump's components.
AODD pumps are designed to handle solids and slurries. When handling fluids containing settling solids, it's important to start the pump up slowly to allow the settled-out solids to evacuate prior to the pump being operated at full flow and pressure. If this doesn't happen, the settled solids can cause damage to pump components.
Installing diaphragm pump surge suppressors virtually eliminates undesirable pulsation from pumping. It also provides virtually pulse-free discharge flow for steadier pressure with less system vibration (vibration can cause damage to the discharge system and loosen connections) and noise.
Completely air-driven (i.e., pneumatic) and ATEX-approved for simple, safe pump control, liquid level controllers protect AODD pumps from inefficient dry running conditions. They essentially turn pumps on and off for intermittent applications.
Common applications for liquid level controllers are:
When in need of replacement parts, order directly from the pump's manufacturer. This reduces downtime and multiple maintenance sessions, as manufacturers make parts specifically to fit their own pumps. Using replacement parts from a different source also will invalidate your pump’s warranty.
AODD pumps are an investment that will pay off with proper installation and maintenance.
For almost 40 years, Versamatic has been one of the largest and trusted manufacturers of world-class, AODD pumps and replacement parts for a broad, global customer base.
Count on the consistency, reliability and trouble-free operation of Versamatic’s bolted metal, bolted plastic and clamped metal AODD pumps offered in a wide range of sizes and flow rates.
A full line of specialty products and support from a team of design and engineering experts with decades of pumping experience keeps your process running smoothly and efficiently. Reach out today or find the closest Versamatic AODD pump distributor.