Goulds Pumps 3311 - IOM - Manual (Page 8)

8
3.1.2 Suction or feed line
A suction line should rise to the pump and a feed line
should slope gradually downward towards the pump.
Feed operation suction operation
Reducers mounted must be eccentric to eliminate the
possibility of air pockets being formed.
Eccentric reducer
If the liquid is contaminated, a filter should be fitted
upstream from the pump whose free-space sectional area
should be three times the pipe cross-sectional area.
CAUTION
• The strainer is for starting purposes only. Solids which
are smaller than the mesh size will not be retained by
the strainer.
• However, such small particles may collect in the
lateral area of the impeller near the clearances, in
particular if their concentration is high.
• In order to prevent clogging, it is recommended that
the customer provide a sedimentation tank or a larger
flushable fine strainer upstream from the pump.
Design:
Conical strainer with perforated plate support body with
external fine screen, mesh size 0.5 mm, of corrosion-
resistant material. The fine screen can be removed after
several months of operation, once there are no more
deposits.
For new conical strainers supplied by Gould’s Pumps the
pressure loss can be calculated as follows:
Hv
g 2
2 v
• = ζ
in m
v = medium flow velocity in reference cross-section,
in m/s
ζ = 4, loss coefficient for new conical strainers
1 Pump suction nozzle / flange
2 Pipe section for strainer
3 Conical strainer
(installed with its tip against flow direction)
4 Feed line
5 Differential pressure measuring instrument
Feed line with conical strainer