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8.5 Pump mounting
8.5.1 Recommended installation torques
8.6 Inlet pipe
The inlet 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 inlet flange). Avoid
using unnecessary fittings, valves or accessory items. Use
butterfly valves in the inlet line only when it is necessary to isolate
a pump because of a flooded inlet 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 inlet
Fig. 6 Inlet lift*
* The inlet pipe should have a fitting on it for priming. CRN-SF
pumps cannot be used for inlet lift.
8.6.1 Inlet pipe sizes
The following recommended inlet pipe sizes are the smallest
sizes which should be used with any specific CR pump type.
Verify the inlet 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.
8.7 Outlet pipe
We suggest to install a check valve and a isolating valve in the
outlet pipe.
Pipe, valves and fittings should be at least the same diameter as
the outlet 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 outlet 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 inlet and
outlet flanges or in pipes to monitor pump and system
performance.
WARNING
Pressurised system
Death or serious personal injury
- The pumps are shipped with covered inlet and
outlet 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
CRT 2/4
30 37-44
CR, CRI, CRN 10/15/20
CRT 8/16
37 44-52
CR, CRN 32/45/64 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. inlet 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, CRN 64 4"
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.
To avoid problems with water hammer, do not use
quick-closing valves in CRN-SF applications.
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