12. Technical data
12.1 Operating conditions
12.1.1 Ambient temperature and altitude
See the instructions for the motor which are
supplied with the pump.
12.1.2 Maximum system pressure and liquid
temperature
The maximum permissible system pressure and
liquid temperature are stated on the nameplate
which is placed on the pump. For identification of
the nameplate data, see the section on the
nameplate.
12.1.3 Maximum permissible operating
pressure and liquid temperature for the
shaft seal
The operating range of a shaft seal depends on
the operating pressure, the liquid temperature and
the type of shaft seal.
The selection charts show which shaft seals are
suitable at a given temperature and a given
pressure.
See the figures below. The charts apply to clean
water.
∅
22 shaft seals for 15-75 HP (11-55 kW)
-40
-4
32
68
248 284
104 140 176 212
0
145
290
435
580
725
HQQE/V
HQBE/V
HQQE/V
HQQE
HQBE
HQQE
(50)
(40)
(30)
(10)
(20)
(-40) (-20) (0)
(20) (40) (60) (80) (100) (120) (140)
p [psi (bar)]
t [ F ( C)]
o
o
TM070324
Maximum permissible operating pressure and
liquid temperature for pumps with
∅
22 shaft
seal (≤ 75 HP (55 kW))
∅
28 and
∅
36 shaft seals for 100-300 HP
(75-224 kW)
0
HQQE/V
HQBE/V
HQQE/V
HQQE
HQBE
HQQE
145
290
435
580
725 (50)
(40)
(30)
(10)
(20)
-40
-4
32
68
248 284
104 140 176 212
(-40) (-20) (0)
(20) (40) (60) (80) (100) (120) (140)
p [psi (bar)]
t [ F ( C)]
o
o
TM070325
Maximum permissible operating pressure and
liquid temperature for pumps with
∅
28 and
∅
36
shaft ends (100-300 HP (75-224 kW))
12.1.4 Minimum inlet pressure
We recommend that you calculate the inlet
pressure "H" in these situations:
•
The liquid temperature is high.
•
The flow rate is significantly higher than the
rated flow rate.
•
Water is drawn from depths.
•
Water is drawn through long pipes.
•
Inlet conditions are poor.
To avoid cavitation, make sure that there is a
minimum pressure on the inlet side of the pump.
Hv
H
NPSH
Pb
Hf
TM0201
18
Schematic view of an open system with a CR
pump
Calculate the maximum suction lift "H" in ft (m)
head as follows:
H
= Pb - NPSH - Hf - Hv (result in ft)
(Pb x 10.2 - NPSH - Hf - Hv (result in m)
Pb = Barometric pressure in feet absolute
(bar).
Barometric pressure can be set to 33.46
ft (1 bar).
In closed systems, Pb indicates the
system pressure in ft (bar).
NP
SH
= Net Positive Suction Head in ft (m) head,
to be read from the NPSH curve in the
appendix at the highest flow the pump will
be delivering.
Hf
= Friction loss in the inlet pipe in ft (m) head
at the highest flow the pump will be
delivering.
Hv = Vapor pressure in ft (m) head. See the
appendix.
tm = Liquid temperature.
If the calculated "H" is positive, the pump can
operate at a suction lift of maximum "H" ft (m)
head.
If the calculated "H" is negative, an inlet pressure
of minimum "H" ft (m) head is required. There
must be a pressure equal to the calculated "H"
during operation.
30
English (US)
