3-1-618 Page 16
8.
Maintaining a slight amount of upward
tension on the fluid end, check the gap
beneath the fluid end supports.
9.
Select
the
proper
number
and
thickness of blocks and/or shims to fill
the gap under the supports.
10. With blocks and/or shims in place,
tighten the four bolts on the fluid end
supports using the appropriate torque.
POWER END LUBRICATION SYSTEM
Due to variety of applications and drive
arrangements, the power end lubrication
pump and applicable auxiliary hydraulic
equipment are not furnished with the triplex
pump. Therefore, the pump lubrication
system is designed and built by individual
customers for each particular application.
The lubrication system is very critical to the
triplex pump performance and therefore
should be professionally designed in
accordance
with
sound
engineering
practices developed for similar systems,
known otherwise as hydraulic power units or
HPU.
The
following
discussion
will
reemphasize some of the good practices
used in designing similar systems in the
past and comment on the system’s critical
components.
Lube System Pump
A positive displacement pump must be
used. Gear type pumps have demonstrated
reliable performance for similar applications
in the past. The pump should have the
largest suction port available for the
selected pump size to minimize losses in
the suction piping.
Lube Pump Suction Piping Sizing and
Requirements
In the past, failure to meet these
requirements has lead to pump damage
because of restricted oil flow in the lube
pump
inlet.
Therefore,
the
following
guidelines, developed as a result of long
experience, should be adhered to closely.
1.
The oil flow velocity through the suc-
tion piping should not exceed 2 ft/sec.
2.
At maximum operating speed the
vacuum reading at the lube pump inlet
must be no more than 8" hg or 4 psi or
0.28 bar.
3.
The suction strainer should be sized for
oil flow three (3) times larger than the
actual
flow
passing
through
the
strainer.
4.
Power End lubrication system should
be filtered with a minimum 25 micron
filter or finer per API specification
2.9.1.5.
5.
The suction pipe should be kept as
short as possible and free of bends.
6.
Warning devices to monitor lube oil
pressure and temperatures are highly
recommended.
The
triplex
pump
operates at very high rod loads and
pressures, and malfunction of the lube
system may result in serious damage
occurring in a very time. Therefore,
early warning devices are essential to
the successful operation and should be
set according to the following operating
limits:
NOTICE
Maximum lube system pressure
should be set at 135 psi (relief
valve setting).
Minimum
lube
oil
operating
pressure is 40 psi (with hot oil).
Approximate lube pump design
flow should be 40 gpm.
Maximum lube system vacuum at
lube pump inlet 8 Hg or 4 psi or
0.28 bar.
FIGURE 3-1 indicates API-GL5 oil grades
recommended for use in the pump power
end and the gear reducer lube system.
Crankcase operating temperature ranges
and minimum startup temperatures for each
