Watson-Marlow 620U - Manual (Page 16)

Watson-Marlow 620UN, 620U, 620SN, 620S User Manual 16
UN, U, SN, S
9 Good pump installation practice
9.1 General recommendations
Position
A correctly engineered installation will promote long tube life. Site the pump on a
flat, horizontal, rigid surface, free from excessive vibration, to ensure correct lubri-
cation of the gearbox. Allow a flow of air around the pump to ensure that heat can
be dissipated. Ensure that the temperature around the pump does not exceed 40C.
Do not stack other 620 pumps on top of this pump. It is, however, acceptable to
stack other equipment on the upper surface of the 620 (as long as the ambient tem-
perature does not exceed 40C).
Emergency disconnection
The pump’s mains plug is the disconnecting device (for isolating the motor drive
from the mains supply in an emergency). Do not position the pump so that it is dif-
ficult to disconnect the mains plug. The STOP key on the keypad will always stop
the pump. However, it is recommended that a suitable local emergency stop device
is fitted into the mains supply to the pump.
Valves
Peristaltic pumps are self-priming and self-sealing against backflow. No valves are
required in inlet or discharge lines. Valves in the process flow must be opened before
the pump operates. Users are advised to fit a pressure relief device between the
pump and any valve on the discharge side of the pump to protect against damage
caused by accidental operation with the discharge valve closed.
The pump may be set up so that the direction of rotor rotation is clockwise or count-
er-clockwise, whichever is convenient.
Tubing materials: run-in advice
Sta-Pure, Chem-Sure and Marprene TM tubing are hard to compress when new.
When using tubing made of these materials, the first five pumphead revolutions
should be at a speed of 10rpm or greater. If the pump is run slower, the safety
system built into pump drive’s software may cause it to stop and display an over-
current error message.
Pressure advice
In most circumstances, rotor and tube life are maximised if the pumphead is run
slowly, particularly when pumping at high pressure. However, to maintain
performance at pressures above 2 bar, avoid running the pumphead below 50rpm.
If low-flow, high-pressure operation is necessary, switching to a smaller tube is
recommended.