FRBH, FRBHX AND FRBHS USER INSTRUCTIONS ENGLISH 71569178 20-08
Page 14 of 60
flowserve.com
®
3.4.2
Speed torque curves
To bring a centrifugal pump up to rated speed, the
driver must be capable of providing more torque at
each speed than required by the pump. The margin
between the available and required torque affects the
time it takes the unit to reach full speed. If the torque
required by the pump exceeds the torque capability of
the drive at any run-up speed, the unit will not
accelerate to full speed. Normally, this is not a problem
with standard induction or synchronous motors
provided the proper voltage is supplied at the motor.
For pumps started at shut valve conditions, 100 percent
full speed torque can be calculated by using the
formula:
Torque (N-m) = 9545 Shutoff Power (kW)
r/min
Torque (lbf-ft) = 5250 Shutoff Power (hp)
r/min
Torque required by the pump at any other speed during
start-up can be determined from the curve above. Note
that the driver manufacturer usually bases 100 percent
torque on the design power of the driver and
consequently the speed-torque curves should be
plotted in torque units (e.g. Nm) instead of percentage
torque to avoid confusion.
3.4.3
MAXIMUM WORKING PRESSURES -bar (psi).
Above ambient temperature these maximum pressures
shall be de-rated.
Do no conduct a hydro on the complete
pump set without the specific approval of Flowserve.
While the duty requirement will have been covered,
auxiliary items, flange drillings and suction pressure
limits may impose a reduced static and dynamic
pressure rating compared to that of the pump casting
rating itself.
Note: all flanges are dimensionally compatible with
ANSI 125 (Cast Iron or Ductile Iron-flat faced) or ANSI
150 (Stainless-raised face) unless otherwise stated. All
flange facings on the casings are 250 rms
–
circular
finish (Stock Finish)
CONSTRUCTION
CAST IRON AND C.I.S.S. FITTED
STAINLESS STEEL
316,317L, WORTHITE, ETC.
TEMPERATURE
O
C (
O
F)
UP TO 12”
DISCHARGE
14 TO 16”
DISCHARGE
18 TO 20”
DISCHARGE
UP TO 16”
DISCHARGE
18 TO 20”
DISCHARGE
-30 to 38 (-20 to100)
10.3 (150)
10.3 (150)
6.2 (90)
13.8 (200)
8.3 (120)
65 (150)
10.3 (150)
9.7 (140)
6.2 (90)
13.8 (200)
8.3 (120)
95 (200)
10.3 (150)
9.3 (135)
6.2 (90)
13.4 (195)
8.3 (120)
120 (250)
10.3 (150)
9.0 (130)
6.2 (90)
12.6 (185)
8.3 (120)
150 (300)
Consult factory for applications in this range. Cast
iron not recommended due to thermal shock risks.
12.1 (175)
8.3 (120)
175 (350)
11.0 (160)
7.6 (110)