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frame. A fixed driveshaft transfers the forces directly into the
pump and PTO and will shorten the life of both considerably.
The yokes of the driveshaft universal joints must be positioned
as shown. Improper positioning will soon wear them out and
potentially destroy the bearings in the pump and PTO.
INLET PIPING should be as short as possible with minimum
restrictions so that the pressure drop is limited. Inlet Piping is not
generally required on the Z3200 or Z4200. These pumps are
bolted directly to the tank internal valve and must be installed in
accordance with the valve manufacturer's instructions.
The Outlet Piping Should Include the Following:
1. A pressure gauge should be installed in the pump outlet
or near it. A pressure gauge is necessary to determine
the efficiency of your pumping system.
2. A hydrostatic relief valve is required by most state laws
and for your own safety.
3. If a meter with a vapor eliminator is installed, pipe
the eliminator outlet to the top of your tank. Never
pipe the eliminator into the pump inlet piping or into
the liquid part of the system at any point.
4. The meter back-pressure valve may be piped into the
tank top or into the pump inlet piping.
5. The discharge piping should be at least the same size
as the meter.
The By-Pass System
The internal safety relief valve is intended as a safety device and
not as an operational by-pass valve. If the pump will be operated
regularly against a closed discharge hose or near the pressure
setting of the internal relief valve, a separate by-pass valve (such
as a 1-1/4" Corken T-166 Valve) must be installed in the discharge
piping system between the pump and the meter. The by-pass
valve should be set at a differential pressure lower than the internal
relief valve (which is set near 150 psid) and may be connected to
the truck tank at any convenient point, liquid or vapor.
Figure 1: Shaft Alignment
Power Take-off Drive Systems
Proper pump operation and long life are directly dependent
upon a good drive system. Many truck pumps utilize a power
train consisting of shafts and universal joints from a power
take-off shaft on the truck engine to the pump.
There are several basic principles that should be followed
in laying out a PTO drive. These principles should not be
violated. Following them will produce a workable power train
that results in long pump life and reduced drive wear.
First, the driver shaft and the driven shaft must be parallel to
one another within plus or minus one degree. Improper
alignment will cause jerking and back and forth "whip" to the
pump shaft, thereby imparting a surging pulsation to the liquid
flow, which results in noise, vibration and abnormal wear.
Second, the angle of the ''floating'' shaft should be within
the limits for the particular equipment being used (usually
a maximum of 15° at pump speeds up to 800 RPM). To
ensure that shaft expansion or contraction does not distort
the drive system, a splined slip joint should be placed
between the two universal joints. The drive shaft should be
of the "splined" or slip type to permit the shaft to adjust for
PTO movement and twisting of the truck frame. A fixed drive
shaft transmits the forces directly to the pump and PTO
which will shorten the life of both considerably.
Third, the yokes of the drive shaft universal joints must be in a
parallel position. Figures 1 and 2 illustrate the proper arrangement.
5
Figure 2: Universal Joint Alignment
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