D/BH Range


Installation, Operation & Maintenance Instructions


1. Installation Recommendations
At the system design stage consideration must be given to the provision for the installation of non-return, isolation or pressure relief values. All pipework should be independently supported.



a) For ease of maintenance the correct dismantling space must be allowed for. (Refer to the dimension sheet)

b) All bolts and nuts securing flanges and base mounting fixtures must be checked for tightness before operation.

c) To eliminate vibration, the pump must be correctly aligned with the drive unit.

d) All guards must be securely fixed in position

e) When commissioning the plant, all joints in the system must be checked thoroughly for leakage

f) Ensure suction pipework is clean to prevent tramp material from damaging the pump.

g) Ensure that footvalve and/ or strainer are suitable sized for the application

2. Duty Condition

Pumps should only be installed on duties for which Mono Pumps have recommended materials of constructions, flow rate, pressure, temperature speed etc. If the duty should be changed Mono Pumps' recommendations should be sought immediately in the interest of safety, plant efficiency and pump life.

3. Starting

Ensure  the correct rotation, preferably with the motor isolated from the pump (COUNTER-CLOCK LOOKING ON SHAFT). NEVER RUN THE PUMP IN A DRY CONDITION, EVEN  FOR A FEW REVOLUTIONS OR THE STATOR WILL BE IMMEDIATELY DAMAGED. Pumps must be filled with liquid before running. Plugs are provided for this purpose. This initial filling is not for priming purposes but to provide the necessary lubrication for the stator until the pump primes itself. When the pump is stopped, sufficiency liquid is normally trapped in it to provide lubrication on starting  again, but if the pump has been standing for some time or has just been moved to a new location or has been dismantled for examination, it must be filled with liquid and given a few turns by hand before starting. The pump is normally somewhat stiff to turn by hand on account of the close fit of the rubber stator. If when starting, the pump does not appear to operate correctly, it must be shut down immediately and the cause of the malfunction established before operation continues.

4. Rotation

The D/BH Range rotates in ONE DIRECTION ONLY. (COUNTER-CLOCKWISE FACING THE DRIVE SHAFT). Incorrect rotation will unscrew the threaded flexshaft possibly causing damage to both rotor and flexshaft. The correct rotation results in the branch at the driving end (GLAND) being the delivery i.e DELIVERY ON GLAND (D.O.G)

5. Gland Packing

All pumps are pre-packed prior to despatch. However, the gland must be adjusted once the pump has been started.

N.B. It is important that there is always a slight leak or drip from the gland

6. Routine Maintenance

a) GLAND PACKING if pump running continuous packing must be changed every three months

b) VEE DRIVE should be checked for belt tension and condition on a regular basis


The Mono Pumps is a Positive Displacement Pump. Therefore, provision must be made for a pressure relief or pressure switch valve on the delivery line should the possibility of a closed discharge condition occur