Instruction Manual IM‐186
CUSTOMER'S INFORMATION BOX
CONTENTS ARE INDEPENDENT OF RIVERHAWK DOCUMENT CONTROL
215 Clinton Road
New Hartford, NY 13413
Tel: +1 315 768 4855
Fax: +1 315 768 4941
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REV
373A4016
GE DRAWING NUMBER
Revision E
Page 15 of 23
10.1 Thread Locking Using a Mechanical Locking Device
Mechanical Locknuts have two set screws located in the top face, see Figure 6. Before threading
the nut onto the stud check to be certain that the set screws are free to turn. Once the nut is
seated torque the set screws to the values specified in the following table. When seated and
torqued to the values specified the load created by the set screw displaces the thread of the
nut in the area of the web creating the desired locking action.
Nut Diameter
Set Screw Size
Torque
2‐1/4"
[58 mm]
1/4"‐28 UN
80 in∙lbs ‐ 90 in∙lbs
[9.0 N∙m – 10.1 N∙m]
11.0 Stud/Nut Removal
Sections 10.1 describes the procedures to be followed in removing nuts that have been
installed with the mechanical locking feature.
11.1 Removal of Assemblies with Mechanical Locknuts
For those assemblies which have been locked using mechanical locknuts, removal is
accomplished as follows:
1.
Using a wire brush and shop air clean the internal tapered thread of the stud to remove any
debris/deposits which may have accumulated during service. (see section 5.2.1)
2.
With an Allen‐wrench loosen the two locking set screws but do not remove from the nut
see Figure 6.
3.
Install the puller tool to the stud as described in Section 6.0. Apply the appropriate
hydraulic pressure per the Table below and using the spanner ring and spanner/pin
wrenches shown in Figure 7 loosen the nut, then release the pressure and remove the
puller tool.
Flange Stud Size Pressure
Turbine/Coupling 2.246 in. 17,000 psi
[57.05 mm] [1170 bar]
