General Pump SK Owner Manual - Manual (Page 12)

GENERAL PUMP
A member of the Interpump Group
SK SERIES
Page 12
The power take-off can be taken from either side of the pump. Generally the pump is supplied with the PTO shank for
the right-hand side (see fig. 6). To get the power take-off from the left hand side, the shaft end cover must be taken off
and remounted on the right hand side of the pump (see 2.1.1 in the Repair Manual). Vice-versa, the lug must be
removed from the right hand side and inserted in the shank of the left hand side.
9.3 Hydraulic Connections
To isolate the plant from the vibrations produced by the pump, we recommend building the first section of hose
adjacent to the pump (for both intake and outlet) with flixible hose. The solidity of the intake section must be enough
to prevent deformation caused by the depression produced by the pump.
9.4 Pump Supply
SK pumps require a positive water head (NPSH
r
) of between 75-100 PSI (5-7 Bar) at the pump head entrance. The
booster supply pump must have a flow rate at least double that of the rated flow rate of the plunger pump, and a mini-
mum pressure of 75 PSI (5 bar). These supply conditions must be respected for any and all working regimes. The
booster pump must be run independent of the plunger pump.
The booster pump must always be started before the plunger pump. We recommend
installing a pressure switch on the supply line downstream of the filters, to protect the pump.
9.5 Suction Line
For the pump’s correct operation, the suction line must have the following characteristics:
1. Minimum internal diameter as indicated in the diagram in paragraph 9.8 and in any case equal or greater
than the pump head’s value. Along the duct, avoid localized diameter reductions that may cause pressure
drops with subsequent cavitation. Absolutely avoid 90 o elbows, connections with other hoses, bottlenecks,
counter-slopes, upside down “U” shaped curves, “T” connections.
2. With a layout that is set in such a way to prevent cavitation.
3. It should be perfectly airtight, and built in a way that guarantees perfect sealing over time.
4. Avoid pump emptying when stopping (even partial emptying).
5. Do not use hydraulic fittings, 3 or 4 way fittings, adapters, etc., since they may hinder the pump’s
performance.
6. Do not install Venturi tubes or injectors for detergent intake.
7. Avoid the use of standing valves, check valves, or any other type of one-way valves.
8. Do not connect the by-pass line from the valve directly to the pump suction line.
9. Provide appropriate baffle plates inside the tank in order to avoid water flows coming from both the by-pass
and feeding lines may create turbulance near the tank’s outlet port.
10. Make sure that the suction line is perfectly clean inside before connecting it to the pump.
11. The pressure gauge for checking booster pressure must be installed near the plunger pump’s outlet port, and
always downstream from the filters.
Ref 300792 Rev.C
06-12