Universal Air Tools UT150 (HP150) - Manual (Page 2)

Operating
The output of the impact wrench in prime working condition is
governed by mainly three factors
a) the input air pressure
b) the time the impact wrench is operated on the joint. Normal
time for joints of average tension requirement 3 to 5 seconds
c) the setting of the air regulator for a given joint at a given
pressure operated for a given time.
The air regulator item (12) can be used to regulate the output of
the impact wrench if no other control means is available. It is
strongly recommended that an external pressure regulator
ideally as part of a filter/regulator/lubricator (FRL) is used to
control air inlet pressure so that
the pressure can be set to help
control the tension required to
be applied to the threaded
fastener joint.
There is no consistent reliable
torque adjustment on an
impact wrench of this type.
However, the air regulator can
be used to adjust torque to the
approximate tightness of a
known threaded joint. To set
the tool to the desired torque,
select a nut or screw of known
tightness of the same size,
thread pitch and thread
condition as those on the job.
Turn air regulator to low
position, apply wrench to nut
and gradually increase power (turn regulator to admit more air)
until nut moves slightly in the direction it was originally set. The
tool is now set to duplicate that tightness, note regulator setting
for future use. When tightening nuts not requiring critical torque
values, run nut up flush and then tighten an additional one-quarter
Dismantling & Assembly Instructions
Disconnect tool from air supply.
Clamp handle of impact wrench in a vice with square drive
upwards. Unscrew four cap screw (48). Take out impact housing
C.P. (45). Turn anvil (36) from hammer wheel (34) and place hole
in anvil to nearest position to
the marking on the wheel.
Take out anvil by hand. If anvil
is difficult to take out by hand,
put a bar into opposite side of
spline hole of the wheel and hit
bar softly with a hammer and
push the anvil out. When the
rotation of the anvil is difficult
because of any internal
damage, hold the wheel with a
vice, turn anvil to a rotatable
direction and dismantle as
above. Take out bushing (42),
plunger A (39), plunger B (41),
spring (40), cam (38), anvil
piece (37) and retainer (35)
from anvil. Clamp motor case C.P. (32) of impact wrench.
Unscrew four cap screws (23). Take out handle C.P. (1) and
motor housing gasket (24). Set motor case C.P. on a workbench.
While lightly tapping on end of rotor (28) with a plastic hammer,
take out rotor and rear end plate (26). Take out rear end plate
from rotor.
Reassembly
Always clean every part and coat every part with a thin film of oil
before reassembly. Apply a film of O-ring lubricant to all O-rings
before final assembly. Insert ball bearing (25) to rear end plate
into the inlet bushing 2 teaspoonfuls (10ml) of a suitable
pneumatic motor lubricating oil preferably incorporating a rust
inhibitor. Reconnect tool to air supply and run tool slowly for a
few seconds to allow air to circulate the oil. If tool is used
frequently lubricate on daily basis and if tool starts to slow or lose
power.
It is recommended that the air pressure at the tool whilst the tool
is running is 90 p.s.i./6.3 bar. The tool can run at lower and
higher pressures with the maximum permitted working air
pressure of 100 p.s.i./7.0 bar. For a lower air pressure the tool
will give a lower output for a given setting of the air regulator set
for 90 psi operation and an increased output for higher
pressures. Hence it is possible that changes in supply pressure
can give situations where the fastener is under or over tightened.
For changes in pressure, the regulator position and application
should be reassessed.
Page No 2
to one-half turn (slight additional turning is necessary if gaskets
are being clamped). For additional power needed on
disassembly work, turn regulator to its fully open position. This
impact wrench is rated a 2" bolt size. Rating must be down
graded for spring U bolts, tie bolts, long cap screws, double
depth nuts, badly rusted conditions and spring fasteners as they
absorb much of the impact power. When possible, clamp or
wedge the bolt to prevent springback.
Soak rusted nuts in penetrating oil and break rust seal before
removing with impact wrench. If nut does not start to move in
three to five seconds use a larger size impact wrench. Do not use
impact wrench beyond rated capacity as this will drastically
reduce tool life.
Note: Actual torque on a fastener is directly related to joint
hardness, tool speed, condition of socket and the time the tool is
allowed to impact.
Use the simplest possible tool-to-socket hook up. Every
connection absorbs energy and reduces power.