These are also know as ‘Hose’ pumps & are a simple flexible hose inside a circular casing that is progressively ‘squashed’ by a rotating shoe or roller. The fluid inside the hose is forced along the hose to the discharge end much like squeezing toothpaste from a tube.
They are relatively simple pumps that have been known to outperform progressive cavity pumps moving abrasive liquids.
Can pass solids
Can process air with the liquid
Few moving parts
Low flow rates at Pressures to 12bar
Good for dosing viscous additives
Lower speeds for abrasive liquids
Low service requirement
Many hose types for good chemical compatibility
Relatively easy to repair
Limited flow rates
Will not tolerate operator misuse
Hoses are Expensive with little inter brand compatibility
Limited fluid temperatures with special hoses required
Hose Life dependant on operating speed.
Expensive in larger sizes
Common brands serviced include;
Bredel, Graco, Watson Marlow, Reddit, Verderflex, Raggazini, and Prominent.