BOMBAS IDEAL RNI Series Use And Maintenance Instructions page 24

Bombas Ideal, S.A.
8.2.- Hydraulic system
The site for placing the pump should be as close as possible to the liquid level, thus avoiding excessively
long suction piping. Its position must meet the criterion that NPSH
For the pump to run properly, take into account that the layout and dimensional design of the suction
piping should meet the following requisites:
1. The suction piping should be short, with as few bends as possible, any such bends to have
a wide curve radius, the last section before the pump must be straight.
2. The diameter must be 1.5 to 2 times the diameter of the pump's suction flange.
3. The inlet cone must be eccentric when the pump works under depression. If it works under
load this cone can be concentric.
4. The piping should be upwards towards the pump, with a slope of at least 2%.
5. It must be properly sealed, preventing the admission of air.
6. When the pump has negative suction, in order to prime it, it should have a suitable foot
valve placed at the required depth (submergence) to prevent air intake through vortices
forming.
The delivery piping must meet the following requisites:
1. Being sealed.
2. Having the proper dimensions to avoid excessive head losses.
3. Having a delivery valve at the outlet of the pump.
4. Where necessary, a non-return valve should be installed between the pump and the
delivery valve as well as the appropriate devices tending to eliminate the harmful effects of
any possible water hammers.
TAKE CARE the pipes should be held on supports close to the pump body so that they do not
transmit any stresses on the pump flanges. Pump and pipe flanges must face each
other perfectly. It's also recommended to use rubber expansion joints to reduce stress
and isolate vibration both on suction and discharge branches.
1. Foot valve with strainer
2. Elbow with large radius
3. Rising pipe. Minimum slope
2%
4. Eccentric cone
5. Vent plug
6. Non-return valve
7. Delivery valve
8. Elastic coupling with spacer
9. Delivery pipe
is higher than the NPSH
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of the pump.
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