12.1 Fluid path system requirements
A Watson-Marlow pump should be installed into a fluid path system with specific ancillary devices to ensure safe
operation. These requirements are detailed in the sections below.
All devices, connections or pipework must be:
l
Chemically compatible with the pumped fluid
l
Have a specification rating higher than that of the application.
12.1.1 Overpressure safety device
A Watson-Marlow pump operates by positive displacement. Should a blockage or restriction occur, the pump will
continue to operate until either of the following occur :
l
The pumphead tubing or element, or ancillary device may rupture, leak or otherwise fail
l
The fluid path pipework or ancillary device, rupture, leak or otherwise fail
l
The drive fails
Install an overpressure safety device which can automatically activate in an overpressure event. This device
should:
l
Be able to be set to a pressure which is lower than the pressure rating of the system
l
Be able to stop the pump or divert the fluid to a safe location upon being triggered
l
Have a fail safe feature
12.1.2 Non-return valve
Install a non-return valve in the
discharge
fluid path as close as possible to the pumphead. This is to prevent
pressurised chemical backflow in the event of a pumphead, tube or element failure. If the pump is to be operated
in reverse, the non-return valve will need to be bypassed during this operation, to avoid becoming a blockage.
12 INSTALLATION: PART 3 (FLUID PATH)
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