Witt GP 41 - 8.3 Preparation of Commissioning

- Installation and application - 34
8.2.1 Flange allignment
GP pumps are designed with a grooved (female) flange on the suction side and a tongue
(male) flange on the delivery side. It is important to ensure the pump connection flanges are
properly aligned before tightening.
Do not use the flange bolts to align or "stretch" the pipe. Using flange bolts to pull together a
too large gap will cause undue stress in the pipework or distort the pump or the flange. Do not
use the mounting bolts to pull down the pump on to the channel framework, the cast iron
mounting foot pads will fracture.
Prior to mounting the pump it should be correctly aligned in height by the use of chim material.
The screws of suction- and delivery flange need to be tightend with a torque of 210 Nm.
8.2.2 Coupling protection
If the pump was not supplied with a motor you have to install a coupling protection
(see right photo).
8.3 PREPARATION OF COMMISSIONING
 The refrigeration system must be pressure tested, vacuum tested and be fully charged with
refrigerant.
 The suction- and discharge valves must be fully open.
 The valves of the pressure differential control, if fitted, must be fully open.
 The pressure differential switch, if fitted, must be set at a difference of at least 20 kPa above
the system static height (static height means "liquid column + pressure difference between
cooler inlet and separator").
 A sufficient volume of refrigerant must be present in the separator or low-pressure receiver
for a minimum running time of approximately 2-3 minutes.
 The electrical control system including all safety controls must be pre-tested prior to starting
the pump.
 Check whether the coupling protection is in place.