Pump maintenance suggestions speak to how to maintain pumps and pump maintenance procedures and to understand what a pump is and its function.
A pump is a device used to move fluids (liquids or gases) or sometimes slurries by mechanical action. Pumps can be classified into three major groups according to the method they use to move the fluid: direct lift, displacement, and gravity pumps.
Pumps must have a mechanism which operates them, and consume energy to perform mechanical work by moving the fluid. The activating mechanism is often reciprocating or rotary. Pumps may be operated in many ways, including manual operation, electricity, an engine of some type, or wind action.
The most common and widely used pumps are known as positive displacement.
Thus, positive displacement pumps produce a constant flow. However due to a slight increase in internal leakage as the pressure increases, a truly constant flow rate cannot be achieved.
A positive displacement pump must not be operated against a closed valve on the discharge side of the pump, because it has no shut-off head like centrifugal pumps. A positive displacement pump operating against a closed discharge valve will continue to produce flow and the pressure in the discharge line will increase, until the line bursts or the pump is severely damaged, or both.
A relief or safety valve on the discharge side of the positive displacement pump is therefore necessary. The relief valve can be internal or external. The pump manufacturer normally has the option to supply internal relief or safety valves. The internal valve should in general only be used as a safety precaution. An external relief valve installed in the discharge line, with a return line back to the suction line or supply tank, is recommended.
A positive displacement pump can be further classified according to the mechanism used to move the fluid:
Rotary-type positive displacement: internal gear, screw, shuttle block, flexible vane or sliding vane, circumferential piston, flexible impeller, helical twisted roots or liquid ring vacuum pumps.
Reciprocating-type positive displacement: piston or diaphragm pumps.
Linear-type positive displacement such as rope pumps and chain pumps.
These suggested maintenance procedures apply to both hot water circulating pumps as well as chilled water circulating pumps.
Suggested pump maintenance
Annual hot water circulating pumps maintenance
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