Maintenance is a word that sometimes takes on an “it can wait until it is scheduled” meaning. It is like a spare tyre in a car—never appreciated until it is needed. However, in mining, any slight interruption or even minor disruption to a harmonic production process can be the beginning of a potential costly death spiral to overall productivity. Dormant pumps mean valuable capital that was spent is not earning back its return on investment
(ROI). Whether above or below ground, there is a need for a robust, long-lasting and a volumetrically efficient workhorse.
Constant pump adjustments, frequent parts changes due to poor duty life, fickle and high-maintenance problems are signs of a “pump in a box” approach to a severe duty application that seldom works in a hot, dry, long life cycle maintenance program or unforgiving environment. Pumps in this kind of service are usually forgotten unless there is a problem. Then they suddenly become centre stage because many, if not all, processes come to a standstill.
The following are some advantages and disadvantages of a positive displacement piston-actuated diaphragm pump for both maintenance and operation:
Benefits of Piston-Actuated Diaphragm Pumps
The ability to have multiple diaphragms that split and share the hydraulic load
High volumetric pumping efficiency by nature
Pump fluids and slurries with a high temperature
Pump fluids and slurries with high solids content and suspended particulates
Pump at relatively high pressures
Work in either single- or double-acting design
Stroke adjustment for maximum efficiency, slow pump speed and low to no vibration
Low horsepower requirements
No seal problems because the diaphragm is the seal (technically hermetically sealed)
Most have integral pressure relief systems
The diaphragm is positioned to the side of the product being pumped and, therefore, is passive pumping
Can last for many years with less overall maintenance
The option of ball check valves, cone valves or flapper valves depending on the application characteristics
Cons of Piston-Actuated Diaphragm Pumps
Higher initial cost
Sometimes take up more space than other pump types. (This may be important in a constricted environment.)
Pump size needs to be increased if the pressure goes up
Higher average cost of spare parts
Longer production delivery times in some cases
Diaphragm pumps are not historically run in parallel or tandem
The piston-actuated diaphragm pump has earned its place in the pump pantheon over the last 40 years of service, but not as an off-the-shelf pump. It has become even less of a niche or custom pump these days as the requirements are ever-changing.
At its best, this kind of pump can earn back the capital investment in a short time due to the low maintenance, repair time, heavy-duty design and energy efficiency. The lack of packing, a mechanical seal, oilers or seal flush plans can make up for the initial higher cost. The diaphragm pump is efficient and often reliable—it can be a set it and forget it proposition.
Article and images courtesy of ABEL Pumps LP
IndustriTech is the Australian distributor for ABEL Pumps. ABEL develops and manufactures reciprocating positive displacement pumps for varying flow rates and pump pressures and specialises in diaphragm pumps. Depending on the design, they are suitable for abrasive, aggressive, and even shear-sensitive media.
IndustriTech can assist you in accurately identifying the best solution to optimise your plant's performance as well as supply a wide range of industrial pumps and compressors, seal supply systems, electric motors, industrial drives, and other industrial process equipment.