Select a location for the pumping unit (pump, base plate, coupling and driver) that will be clean, well ventilated, properly drained and provide accessibility for inspection and maintenance (see outline drawing for dimension) Outdoor installations may require protection from the elements particularly freezing.
The suction supply system must provide the pump i.e. the suction tank location with its base or above the same elevation of the pump.
Foundation: Concrete, (reinforced as necessary or required) is most widely used for the foundation of fire pumps. In sufficient mass, it provides rigid support, which minimizes deflection and vibration.
It may be located on soil, structural steel or building floors, provided the combined weight of the pumping unit.
Fire Pump Mounting On Foundations
Use qualified personnel (riggers) to lift or move unit at any time. Never lift unit using hooks or slings on shafts Never place eye-bolts in tapped holes except for removal of a part to perform service work.
When the unit is received with the pump and the driver mounted on the base plate, it should be placed on the foundation and the coupling halves disconnected. The coupling should not be reconnected until the alignment operations have been completed. The base plate should be supported on rectangular metal blocks and shims or on metal wedges having a small taper. The support pieces should be placed close to the foundation bolts on large units, small jacks made of cap screws and nuts are very convenient. In each case the supports should be directly under the part of the base plate carrying the greatest weight and spaced closely enough to give uniform support.
Adjust the metal supports or wedges until the shafts of the fire pump and driver are level. Check the coupling faces as well as the suction and discharge flanges of the pump for horizontal or vertical position by means of a level. Correct the positions, if necessary, by adjusting the supports or wedges under the base plate as required.
Firefighting Pumps and drivers mounted on a common base plate are accurately aligned before shipment. Realignment is necessary after the complete unit has been leveled on the foundation and again after the grout has set and foundation bolts have been tightened. The alignment must be checked after the unit is piped and rechecked periodically. To facilitate accurate field alignment, do not dowel the pumps or drivers on the base plates before shipment.
Firefighting Pump Alignment
Reliable, trouble‐free, and efficient operation of a pumping unit requires correct alignment of pump and driver shafts. Misalignment may be the cause of:
- Noisy pump operation
- Premature bearing failure
- Excessive coupling wear
Factors that may change the alignment of the fire pumping unit are:
- Setting of the foundation
- Springing of the base plate
- Piping strains
- Settling of the building
- Shift of pump or driver on the foundation
Correct for excessive parallel and angular misalignment by slightly shifting the leveling wedges under the base plate. Tap tightly (in or out) with a hammer. Retest alignment after each shifting of a wedge. In some instances, for factory aligned pumping units, it may be necessary to change the shims under the pump or driver, or even relocate these factory‐positioned units on the base plate.
Make such changes only after it is certain alignment cannot be obtained by shifting of the wedges. If wedges are shifted or shims changed a substantial amount to obtain proper alignment, recheck the piping alignment and level of the shafts.
Firefighting Pump Piping Works
The suction and discharge piping should be arranged for the simplest, most direct layout, to be of sufficient size and be internally free of foreign material. The piping must never be pulled into position by the flange bolts. It must be independently fixed and arranged. The suction piping, if not installed properly, is a potential source of faulty operation. To achieve best performance:
- the suction lines ,when operation must be kept absolutely free from air leaks.
- A strainer should be installed in suction line . The screen must be checked and cleaned periodically. The opening in the screen must smaller than the sphere size allotted fro the impeller.
- Piping should be cleaned mechanically and chemically , and flushed prior to installing the pump. A large number of pump packing , mechanical seal and seizure troubles are due to improperly cleaned systems.
- The Pump should also be inspected internally for foreign matter that may have entered the pump.
- The suction pipe shall be sized such that pump capacity and minimum distance to be maintained from suction pump flange.