9. Repeat step 8 for the remaining “first pass”
tensioners in the circuit.
10. Release the hydraulic pressure by SLOWLY
opening the pump pressure release (return
to tank) valve. Verify that the oil pressure
gauge indicates zero (0) psi/bar. See
Figure 10.
11.
Check the stroke indicator at each
tensioner in the circuit. If necessary, turn
down the threaded puller until the piston is
fully retracted into the tensioner body. See
Figure 11.
12. Repeat steps 5 through 11 a second time
(to pressure “A”).
13. Repeat steps 5 through 11 a third time (to
pressure “A”).
14. Move the tensioners to the remaining 50%
of the bolts (i.e. all bolts numbered “2”).
See Figure 13.
15. Determine the “second pass” pressure “B”
value. This value must be calculated by a
qualified engineer with bolting experience.
Note:
The pressure “B” value is typically
lower
than the pressure “A” value (see note after step
4 for additional information).
16.
Operate the pump and pressurize the
tensioners up to approximately 1000 psi
[70 bar]. Check for oil leaks.
17. If no leaks are found, continue pressurizing
the tensioners to the calculated “second
pass” pressure “B” value determined in
step 15. Continually observe the tensioner
stroke and hydraulic pressure at all times
during pressurization.
18. When the “second pass” pressure “B” is
reached, stop the pump. Recheck the oil
pressure gauge after pump has stopped.
Be sure the pressure remains stable (not
increasing or decreasing). Threads may
be visible between the nut and the joint
surface at each tensioner. See Figure 7.
19. While holding the pressure constant, use
a tommy bar to turn down the first socket
and nut by hand. Continue tightening until
the nut is firmly seated against the joint
surface. See figures 8 and 9.
20. Repeat step 19 for the remaining “second
pass” tensioners in the circuit.
21. Release the hydraulic pressure by SLOWLY
opening the pump pressure release (return
to tank) valve. Verify that the oil pressure
gauge indicates zero (0) psi/bar. See
Figure 10.
22.
Check the stroke indicator at each
tensioner in the circuit. If necessary, turn
down the threaded puller until the piston is
fully retracted into the tensioner body. See
Figure 11.
23. Repeat steps 16 through 22 a second time
(to pressure “B”).
24. Repeat steps 16 through 22 a third time (to
pressure “B”).
25.
As an optional check to determine
if an excessive load has been lost
in the first 50% of bolts tightened
(bolts numbered “1”):
B1
FIGURE 16, DETERMINING THRE “BREAK
LOOSE” PRESSURE
Note:
Try to turn up the nut while slowly raising the
hydraulic pressure. When the nut just begins to turn,
the “break loose” pressure (B1) has been reached.
B1 = Break Loose
Pressure
FIGURE 15, TURNING UP THE THREADED
PULLER
0
PRESSURE
RELEASE
OPEN
Gap = 1/2 turn
PRESSURE
RELEASE
CLOSED
12
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