3
Eng
lish (US
)
chapter discard.fm Page 3 Tuesday, June 7, 2011 9:29 PM
HS 100, HS 125, and HS 150
HS 150
(2 and 3 hp)
(5 and 7 1/2 ph)
FIGURE 1: Bolt hole centers
Pipework
The use of pipe compound or teflon tape on all male threads
is acceptable as a means of providing a positive seal at the
pump port conditions. Avoid using unnecessary fittings,
valves or accessory items, especially in the vicinity of the
pump suction and discharge ports. The piping should be
adequately supported to reduce thermal and mechanical
stresses on the pump.
Good installation practice recommends the system be
thoroughly cleaned and flushed of all foreign materials and
sediment prior to pump installation. If possible, the pump
should not be installed at the lowest point in the system
due to the natural accumulation of dirt and sediment. If
there is excessive sediment or suspended particles present,
it is advised a strainer or filter be used to prevent its entry
into the pump.
Suction pipe
The suction pipe should be adequately sized and run as
straight and short as possible to keep friction losses to a
minimum. This would generally dictate that the suction
piping, fittings, valves and accessories be at least as large
as the suction port connection of the pump. These should
be larger if the distance to the water source is great.
Care should be taken to provide a means of pump isolation
(e.g., gate or butterfly valves) in applications where the
pump is in a pressurized or flooded suction condition.
If the pump is installed in a suction lift application, hori-
zontal suction piping must rise gradually from the source
to the pump and contain no high spots which allow air
pockets to form.
Discharge piping
It is suggested that a check valve and isolation valve be
installed 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
fluid velocities and pipe friction losses. Pipe, valves and
fittings must have a pressure rating equal to or greater
than the maximum system pressure. Before the pump is
installed, it is recommended that the discharge piping be
pressure checked to at least the maximum pressure the
pump is capable of generating or as required by codes or
local regulations.
The standard discharge position for Grundfos Series
HS pumps is vertical (upward). To simplify pumping
connections, however, the pump volute may be rotated to
optional positions. The HS 100, HS 125, and HS 150 (2 HP
and 3 HP) models may be rotated to any of four positions
while the HS 150 (5 HP and 71⁄2 HP) may be rotated to any of
six positions. (See Figure 2).
HS 100, HS 125
HS 150
HS 150 (2 hp and 3 hp)
(5 hp and 7 1/2 hp)
(4) discharge positions
(6) discharge positions
FIGURE 2: Piping connection positions
(viewed from suction end)
Reposition the pump volute as follows:
1. Loosen and remove each of the cap screws that attach
the pump volute to the motor stool.
2. Carefully lift the pump volute off of the motor stool
and rotate it to the required position. Check that the
o-ring is properly seated.
3. Apply teflon sealant to the cap screw threads.
4. Reinstall the cap screws and tighten diagonally and
evenly.
Bypass
A bypass or pressure relief valve should be installed in the
discharge pipe if there is any possibility that the pump may
operate against a closed valve in the discharge line. Flow
through the pump is required to ensure that adequate cool-
ing and lubrication of the pump is maintained. See Table A
on page 4 for minimum flow rates.
