Connecting The Piping - Boulton Pumps ESK Series Instruction For Operation And Maintenance

2.3.5. Connecting the Piping

2.3.5.1. General
Never use the pump as an anchorage point or as a carrier for the piping.

The pipes should be supported very near the pump (Fig. 5). It must be checked that any weight, stress or strains on
the piping system should not be transmitted to the pump. Therefore after completing the piping installation, the bolt
and connection on the suction and discharge nozzles must be loosened to ensure that there is not any stress on the
piping system to the pump.

The nominal sizes of the pump suction and discharge nozzles are no guide to the corrects sizes of the suction and
discharge piping. The nominal bores of the pipes should be same as or greater than those of the pump nozzles. Never
use pipes or accessories which have smaller bore than the pump nozzles. Particularly foot valves, strainers, filters
and non return valves must be preferred with larger free transition areas. In general the flow velocities should not
exceed 2 m/s in the suction piping and 3 m/s in the discharge piping. Higher flow velocities will result in higher
pressure drops, which could cause cavitation conditions in the suction piping and excessive friction losses in the
discharge piping.

Pipe joints should be by means of flanges with flange gaskets of proper size and material. Flange gasket must be
centered between the flange bolts in a such way that there is no interference with the flow of the liquid.

Thermal expansions of the pipework and excessive vibrations should be accommodated by suitable means so as not
to impose any extra load on the pump.

Prevent impurities such as welding beads, scale, sand and tow might be left in pipes while production of the piping
system harms the pump. Seal the pump nozzles by means of blind gasket to stop impurities get in the pump. After
assembling the system all the piping parts must be disassembled, thoroughly cleaned, painted and reassembled
again. If a strainer is used on the suction side of the pump, it must be cleaned after several days of operation.
Fig. 5a. Suction Lift
2.3.5.2. Suction piping (Fig. 5, 6)

The suction piping must be absolutely leak-tight and not present any features likely to promote the formation of air
pockets. Suction piping therefore should have a slight downward slope towards the pump in the case of suction head
installation (e.g. flooded suction) and slight upward slope towards the pump in the case of suction lift installation.

In order to keep the pipe friction losses as low as possible it is essential to avoid any sharp bends and abrupt changes
of direction or cross-section and the suction pipe should be kept as short as possible. If it is necessary to change the
cross-section of a piping laid almost horizontal, an eccentric reducer, with top horizontal, should be used.

A positive suction head piping should incorporate an isolating valve with the valve stem in the horizontal position.
This valve should always remain fully open while the pump is running and must not be used to regulate the flow.
Fig. 5b. Suction Head
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