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English (US)
8.3 Pump mounting
8.3.1 Recommended installation torques
8.4 Suction pipe
The suction pipe should be adequately sized and run as straight
and short as possible to keep friction losses to a minimum
(minimum of four pipe diameters straight run prior to the suction
flange). Avoid using unnecessary fittings, valves or accessory
items. Use butterfly valves in the suction line only when it is
necessary to isolate a pump because of a flooded suction
condition. This would occur if the water source is above the
pump. See fig. 5 and fig. 6. Flush piping prior to pump installation
to remove loose debris.
Fig. 5 Flooded suction
Fig. 6 Suction lift*
* The suction pipe should have a fitting on it for priming. CRN-
SF pumps cannot be used for suction lift.
8.4.1 Suction pipe sizes
The following recommended suction pipe sizes are the smallest
sizes which should be used with any specific CR pump type.
Verify the suction pipe size in each installation to ensure that
good pipe practices are being observed and excess friction
losses are not encountered.
High temperatures may require larger diameter pipes to reduce
friction and improve NPHSA.
8.5 Discharge pipe
We suggest to install a check valve and a isolating valve in the
discharge pipe.
Pipe, valves and fittings should be at least the same diameter as
the discharge pipe or sized in accordance with good piping
practices to reduce excessive flow velocities and friction losses in
pipes.
Before installing the pump, pressure check the discharge piping
to at least the maximum pressure the pump is capable of
generating or as required by codes or local regulations.
Whenever possible, avoid high pressure-loss fittings, such as
elbows or branch tees directly on either side of the pump.
The piping should be adequately supported to reduce thermal
and mechanical stresses on the pump.
According to good installation practices, clean the system
thoroughly and flush it of all foreign materials and sediment prior
to pump installation. Furthermore, never install the pump at the
lowest point of the system due to the natural accumulation of dirt
and sediment. If there is excessive sediment or suspended
particles, we recommend that a strainer or filter is used.
Grundfos recommends that pressure gauges are installed on
suction and discharge flanges or in pipes to monitor pump and
system performance.
Warning
CR, CRI, CRN pumps are shipped with covered
suction and discharge ports. Remove the covers
before the pipes are connected to the pump.
Pump type
Recommended
foundation torque
[ft-lbs]
Recommended
flange torque
[ft-lbs]
CR, CRI, CRN 1s/1/3/
5 and CRT 2/4
30 37-44
CR, CRI, CRN 10/15/
20 and CRT 8/16
37 44-52
CR, CRN 32/45/64/90/
120/150
52 52-59
TM05 9273 3613
TM05 9274 3613
Strainer
Reservoir
Butterfly
valve
Check
valve
Expansion joints
Butterfly
valve
Eccentric
reducer
Butterfly
valve
Suction
pipe
Foot valve
Reservoir
Check
valve
Pump type Min. suction pipe size
CR, CRI, CRN 1s, 1, 3;
CRT 2
1"
Nominal diameter acc. to
ANSI schedule 40
CR, CRI, CRN 5; CRT 4 1 - 1/4"
Nominal diameter acc. to
ANSI schedule 40
CR, CRI, CRN 10, 15, 20;
CRT 8, 16
2"
Nominal diameter acc. to
ANSI schedule 40
CR, CRN 32 2 - 1/2"
Nominal diameter acc. to
ANSI schedule 40
CR, CRN 45 3"
Nominal diameter acc. to
ANSI schedule 40
CR, CRN64, 90 4"
Nominal diameter acc. to
ANSI schedule 40
CR, CRN 120, 150 5"
Nominal diameter acc. to
ANSI schedule 40
The pressure rating of pipes, valves and fittings
must be equal to or greater than the maximum
system pressure.
Warning
To avoid problems with water hammer, do not
use quick-closing valves in CRN-SF applications.
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