© SPX FLOW, Inc.
Form No. 1000623
Rev. 6 Jan. 10, 2017
Torque Wrench Usage
To ensure reasonable life and performance from the torque wrench and system (pump and hoses),
these guidelines should be followed:
• Under normal use, the torque wrench should be limited to 75–80% of its maximum achievable torque
output.
• Under breakout conditions, because the bolt can suddenly break free and result in shock loads,
jumping/jolting, it is recommended to limit the wrench output torque to 60–70% of maximum
achievable torque output. It is also a good idea to have torque in reserve for the odd stubborn bolt/
nut.
• Once a corroded bolt has broken free, do not use a torque wrench to wind the nut from the bolt. This
can cause the nut to bind and lock onto the bolt and make it impossible to remove. It is preferred
that a nut runner or impact wrench be used to remove the nut following initial breakout by hydraulic
torque wrench.
• Occasional use of the torque wrench at full pressure/torque is acceptable, but unnecessary
continuous use at full pressure will reduce the life of the torque wrench and system.
• In elevated temperature environments, it is advisable to cool the torque wrench as much as practical
to maintain the sealing systems in good order. Depending upon the pressure applied to the wrench,
repeated use in temperatures in excess of 40°C (104°F) will affect the life of the hydraulic seals.
If the temperatures are likely to exceed 40°C (104°F), it is advisable to use a larger capacity wrench
so that the pressure to achieve the required torque is reduced. This will result in less temperature
buildup and less softening of the seals.
Seals should be replaced regularly because, at elevated temperatures, the extrusion resistance of
the seal is reduced.
Connecting the System
The hydraulic wrench head and power pack are connected by a 690 bar (10,000 psi) twin-line hose
assembly. Refer to the power-unit manufacturer's operating instructions for proper use.
Hydraulic Connections
•
Never connect or disconnect any hydraulic hoses or fittings without first unloading the
wrench and the pump.
•
Open all hydraulic controls several times to verify the system has been completely
depressurized.
•
If the system includes a gauge, double check the gauge to verify pressure has been
released.
•
When making connections with quick-disconnect coupling, verify the couplings are fully
engaged. Threaded connections such as fittings, gauges, etc., must be securely tightened
and leak-free.
Use of Sockets
Use high-quality, industrial impact sockets at all times. Verify that sockets are rated to accept the full
torque output of the torque wrench they are used with. Regularly check the socket for cracks and flaws.
If any sign of damage is evident, discard immediately. A damaged socket breaking under load can
cause equipment damage or operator injury.
Initial Setup continued