What is a sealless magnetic drive pump?
A sealless pump is essentially a conventional centrifugal pump without packed glands or mechanical seals. The dynamic seal that would normally be used to seal the impeller shaft is instead replaced by a static containment shell, or shroud, to form a completely sealed liquid end or pressure boundary.
Prime mover energy is transmitted to the sealed liquid end by a bank of external magnets, which pass force through the containment shell to the impeller shaft.
Why is it sealless?
Mechanical seals are designed to maintain their sealing capability by leaking small amounts of fluid as a means to keep the seal faces lubricated. This leakage then reaches the environment as either liquid or vapour via a process referred to as fugitive emission.
According to a report by the United Kingdom Health and Safety Executive, mechanical seals are widely regarded as the weakest point in any pumping system using them. They account for 80% of all pump failures, the remainder being leakage through static seals such as gaskets / O rings and bearing failure. It follows that if you eliminate the problem, you eliminate the failures and save costs.
Sealless pumps don’t leak, meaning that they can help reduce process inefficiencies, maximise output and minimise the risks posed to your process environment by hazardous and volatile materials.
Furthermore, seals, like bearings, must wear. As they wear, the seal faces lose their effectiveness and liquid loss through the seal increases. These fugitive emissions can be costly, resulting in lost time and money, as well as decreased worksite safety.
Without these seals — which will ultimately fail, requiring expensive maintenance — our sealless magnetic drive pumps represent a cost-effective and highly reliable alternative to traditional sealed pump designs.
What else is different?
The containment shell of a HMD Pump is either of welded construction to ASME VIII pressure vessel standards and typically of 1.2mm thickness or the latest ZeroLoss® shell. This will improve efficiency and reduce equipment life cycle costs. Our competitors usually have hydroformed shells, which are much thinner and weaker than the HMD Kontro design. Rotating parts are dynamically balanced ensuring smooth, quiet operation and longevity.
HMD Kontro pumps are a modular cartridge, which can reduce maintenance time considerably. This method of construction means that there are many common components for each of the three frame sizes throughout the range, reducing the need for a large stock of spare parts in a multiple pump installation.
The outer magnet ring is fully encapsulated, meaning that the magnets are protected from being chipped on assembly and against corrosion from the pumped liquid in the event of containment shell breach. It also means that the component can be easily cleaned in usual workshop conditions.