8.5 Pump mounting
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.
8.5.1 Recommended installation torques
Recommended
Pump type
foundation torque
CR, CRI, CRN 1s/1/3/5
CRT 2/4
CR, CRI, CRN 10/15/20
CRT 8/16
CR, CRN 32/45/64
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.
piping prior to pump installation to remove loose debris.
Butterfly
valve
Check
valve
Expansion joints
Fig. 5
Flooded inlet
Butterfly
Check
Eccentric
valve
valve
reducer
Fig. 6
Inlet lift*
* The inlet pipe should have a fitting on it for priming. CRN-SF
pumps cannot be used for inlet lift.
Recommended
flange torque
[ft-lbs]
[ft-lbs]
30
37-44
37
44-52
52
52-59
5
and fig. 6. Flush
Reservoir
Butterfly
valve
Strainer
Suction
pipe
Reservoir
Foot valve
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.
Pump type
CR, CRI, CRN 1s, 1, 3
1"
CRT 2
CR, CRI, CRN 5
1 - 1/4"
CRT 4
CR, CRI, CRN 10, 15, 20
2"
CRT 8, 16
CR, CRN 32
2 - 1/2"
CR, CRN 45
3"
CR, CRN 64
4"
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.
The pressure rating of pipes, valves and fittings must
be equal to or greater than the maximum system
pressure.
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.
To avoid problems with water hammer, do not use
quick-closing valves in CRN-SF applications.
Min. inlet pipe size
Nominal diameter acc. to
ANSI schedule 40
Nominal diameter acc. to
ANSI schedule 40
Nominal diameter acc. to
ANSI schedule 40
Nominal diameter acc. to
ANSI schedule 40
Nominal diameter acc. to
ANSI schedule 40
Nominal diameter acc. to
ANSI schedule 40
15