5
Expansion Tank Installation
Mount the expansion tank so it is the highest point in
the system and if possible at least 15 feet (5m) above
the height of the pump. Connect the fluid level sight
glass to the expansion tank. To safeguard employees
and equipment, run the vent line either out of the build-
ing or down into a 55 gallon drum. The vent line piping
should match the port size on the expansion tank.
To avoid possible rupture of expansion tank
due to pressure, vent line should be checked
on a regular basis to be sure it is always open
to the atmosphere. Failure to do so may result
in rupture of the expansion tank or other parts
of the system causing injury or hazard.
Note: If the expansion tank cannot be mounted above
the highest point in the system, or if the system is going
to operate above the boiling temperature of the heat
transfer fluid, the expansion tank will have to be pres-
surized. This eliminates the possibility of heat transfer
fluid flashing into vapor in the heater, at the point of
high velocity in the system, at the suction of the pump
or causing the pump to vapor lock due to insufficient
NPSH (net positive suction head). This pressure should
be 5-10 PSI (0.34 - 0.69 bar) above the vapor pressure
of the heat transfer fluid at its operating temperature.
If expansion tank is to be pressurized, then it
must be equipped with safety relief valve(s). If
this pressure exceeds 15 PSIG, then the heat
transfer system and expansion tank should be
ASME certified.
DO NOT mount expansion tank directly on top of
system
unless absolutely necessary. If mounted on
system, provisions must be made for cooling of the
expansion tank line. Maximum safe operating tempera-
tures are reduced when expansion tank is mounted on
system unless positive suction pressure of 2 to 3 psig
(0.14-0.21 bar) is maintained on pump.
Pump Motor
The pump/motor is a close-coupled centrifugal pump
rated for 300˚F (149˚C). Pump and motor mounts should
be checked and tightened if loosened during shipment.
DO provide for expansion and contraction of process
piping and connections to the system. Piping strains
can cause pump and motor misalignment, excessive
wear on pump body, bearings and stuffing box packing
or mechanical seal and will eventually cause failure of
the pump and system.
Piping should be properly supported so pump can be
removed without changing the position of the piping.
If piping moves when the pump is removed, pump
malfunction is probably due to stresses and twisting
caused by the piping. These stresses will multiply when
the system is hot due to thermal expansion.
Refer to graphs for pump performance curves.
50-150 kW Unit (3 hp)
18
PER HOUR
CUBIC METERS
4
9
14
U.S. GALLONS
PER MINUTE
6
9
12 17
20
40
18 26
24
30
35
43
60
80
100
37 52
43 61
120
140
20
40
60
80
27
22
120
100
60 Hz
MTRS
TOTAL HEAD
PSI FEET
3500 RPM
70°F
1.0 S.G.
20
10
0
N
P
S
H
R
F
E
E
T
0
0
NPSH REQ.
5.25
50 55 60 65
70
70
65
60
3 HP