Air-operated double diaphragm pumps are a versatile option for a variety of applications. Some of the key features of diaphragm pumps are: No rotary or sliding seals in contact with the pumped liquid, reducing maintenance costs and allowing them to run dry without causing any damage. Speed is varied by the air inlet, so no variable speed drives are required and the output is infinitely variable. The pump discharge pressure can’t be more than the air pressure, so pressure rel

The impeller on a submersible pump makes a big difference in preventing blockages. Whether it’s for storm water or sewage, for high peak flows or just occasional use, choosing the right option will have long-lasting benefits. Every type balances the need for efficiency and the need to handle varying solids sizes and quantities. Each manufacturer has their own range of precisely designed versions, and the four main choices of submersible pump impeller are described below. V

Here are the basics of reading the key points on a pump curve. The pump curve used for this illustration is for a Grundfos in-line circulator pump, and the principles apply to most types of centrifugal pump. A The required ‘Head’ (output pressure) from the pump is set at 4 metres. This is a combination of the vertical distance the pump needs to push the water, and the extra pressure put on the pump by ‘friction losses’ (the effort of getting the water through the pipework,