WCB 11060 (PDF Format)
10
© Copyright Eaton Corp., 1998. All rights reserved
June, 1998
Table 6
Air inlet size
Model
Thread Size
18 WCB
1/2-14 NPT
24 WCB
1/2-14 NPT
36 WCB
3/4-14 NPT
2.4
Air System
Maximum allowable air pressure is
150 PSIG (10.3 bar). Application of
pressure exceeding maximum
allowable may result in damage to
the tensioner.
2.4.1
All pipes should be free of metal chips,
cutting compound and any other foreign
matter. Pipe ends should be reamed after
cutting to eliminate possible restrictions.
A minimum of bends and elbows should
be used.
2.4.2
Air inlets for the WCB are on the face of the
cylinder (19). See table 6. Use only clean,
filtered air (a 50 micron filter or better is
recommended) which is free of excess
moisture.
2.5
Coolant System
Maximum allowable water pressure
is 40 PSIG (2.7 bar). Application of
pressure exceeding maximum
allowable may result in damage to
the tensioner.
2.5.1
Coolant supply connections to the tensioner
should provide a parallel flow through each
section of the tensioner. Series flow is not
generally recommended, contact Airflex for
specific applications. Inlet and outlet coolant
manifolds must be provided with flexible
connecting hose to each tensioner coolant
section. Coolant supply connection to the
tensioner must be flexible to allow axial
travel of the pressure plate and reaction
plate during tensioner operation. Coolant
and coolant supply lines should be free of
foreign material (a 500 micron water filter
is recommended). Reductions in the
recommended line diameter should be
avoided. Avoid loops and bends in the
lines which may create air pockets, which
substantially reduce the flow of coolant.
Figure 7 illustrates a typical closed loop
liquid to liquid coolant system. The heat
exchanger and temperature control would
be replaced with a radiator, fan and motor
in a liquid to air system.
2.5.2
Figure 7 shows the flow control valve settings
for each type of element depending on the
number of friction surfaces to be cooled.
Make sure that the water inlets and
outlets are at the 6 o’clock and 12
o’clock positions, respectively. This
will ensure that there will be no air
pockets in the water cavity during
operation, which would allow the
tensioner to overheat.
2.5.3
The coolant supply and discharge pipe
sizes, along with minimum flow rates for
the tensioner rated horsepower, are given
in Table 7.
2.5.4
Each coolant cavity of each WCB tensioner
has been statically tested at the factory
before shipment. If leakage is suspected,
a static or dynamic test may be made as fol-
lows:
Static Pressure Test:
First, bleed all air from within the coolant
cavity. Air bleeding must be accomplished by
running coolant through the cavity with the
tensioner secured in its operating position.
After the air has been removed, install
a pipe plug in the outlet and apply 40 PSIG
(2.7 bar) coolant pressure measured at the
inlet to the water cavity. Maintain this
pressure for 30 minutes. Check for leakage
at O.D. and I.D. seal areas.
Do not apply air pressure to the
cylinder of the tensioner during
static coolant pressure testing.
Surge pressures exceeding 40 PSIG
(2.7 bar) could be developed within
the coolant cavities which will cause
damage to the seals.
