Flowserve Worthington WXB - Manual (Page 16)

WXB USER INSTRUCTIONS ENGLISH - 07/14
Page 16 of 51
strainer of 40 mesh.
Piping for corrosive liquids shall be arranged to allow
pump flushing before removal of a unit.
4.5.2 Inlet Piping Requirements *
Inlet flow disturbances, such as swirl, unbalance in
the distribution of velocities and pressures, and
sudden variations in velocity can be harmful to the
hydraulic performance of a pump, its mechanical
behavior, and its reliability.
The minimum required straight pipe length (L2)
before pump suction inlet is specified in Table 01.
The straight pipe section is to be the same diameter
as that of the pump section nozzle.
Table 01
Fitting*
Number of pipe diameters (ØD2)
Long radius ** Short radius **
90° elbow 4 5
Reducing elbow with
<30% area reduction
3 4
Reducing elbow with 30
to <50% area reduction
2 3
Reducing elbow with
>50% area reduction
0 1
Reducers Concentric Eccentric
-) 1 pipe size reduction 0 (<10°) 0 (<20°)
-) 2 pipe size reductions 0 (<20°) 1 (<30°)
-) 3 pipe size reductions 1 (<20°) 2 (<30°)
-) 4 pipe size reductions 2 (<20°) 3 (<40°)
-) 5 pipe size reductions 3 (<30°) 4 (<40°)
* excerpt from ANSI/HI 9.6.6-2009
** according to ASME B16.9-2003
4.5.3 Vent
All WXB pump casings provide self venting through
top discharge nozzle arrangement. A small bore at
the top of the seal chamber ensures venting of the
same.
4.5.4 Drain
This connection is used for total drainage of the pump
casing. A flanged drain is standard and can be
optionally equipped with various kinds of valves.
Refer to GA drawing for details of the drain
connection.
By pumping toxic or explosive
media, provide the necessary security actions, e.g.
flushing with nitrogen.
4.5.5 Warm up requirements
A warm up arrangement is a means for maintaining
an idle pump at approximate uniform temperature.
We recommend a warm up procedure for liquid
temperatures above 150°C (302°F).
Most commonly this arises when the pump is in boiler
feed service. The pump which is started first will
experience a gradual increase in water temperature
after the boiler is fired and the unit warms up.
However, when a second pump is to be put on the
line, it is desirable to first bring it nearly to the
prevailing feed water temperature by circulating water
through it before it is started. Likewise, when a pump
has been in operation and is taken off the line and
shutdown, it is essential that water be circulated
through it to maintain a uniform temperature.
Otherwise it results in distortion of the close-running
parts. If such a pump is started, rubbing would occur
inside the pump.
A general arrangement of warm up piping is
illustrated below.
Warm up flow:
2WXB: 2 m
3
/h (8,8 gpm)
3WXB: 3 m
3
/h (13,2 gpm)
4WXB: 4 m
3
/h (17,6 gpm)
6WXB: 5 m
3
/h (22 gpm)
Direction of
Fluid Flow