P : 8 5 5 . M P S . S H I P
m a c l e a n p o w e r . c o m
4 8 1 M U N N R D S U I T E 3 0 0
F O R T M I L L , S C 2 9 7 1 5
RECOMMENDED PROOF TEST METHOD
Please refer to Drawing #E1012-A
To achieve the best accuracy of Load Locking and Proof testing, set the Bypass Valve
on the Jack to the required proof test value prior to Load Locking or proof testing. This
allows the operator to fully shift the valve to the extend position while monitoring
movement of the anchor without having to worry about controlling the load by
“feathering” the control valve. This method of load locking using the LL-1 results in a
load accuracy of +/- 10% in the range of 5000 to 20000 lbs. If greater accuracy is
required or if the application is critical, then the user should have the LL-1 FPM jack and
power source combination calibrated by an independent test Laboratory.
ADJUSTING THE BYPASS VALVE
WARNING: The bypass valve setting is dependent upon the input flow and pressure.
Care should be taken to ensure that the flow and pressure supplied by the hydraulic
power unit are the same as those that will be used in service.
1. Place the jack assembly on the floor, bench or ground without the base plate,
tapered jaws or adapter setting bar.
2. Connect the jack to the same hydraulic power source that will be used in service
for locking anchors.
3. Start the hydraulic power source and set the throttle at the same position that will
be used in service.
4. Extend the jack to the top of its stroke. Keep the control valve shifted fully to the
extend position. The bypass valve will now be limiting the hydraulic pressure.
You can usually hear a “screeching” sound when the bypass valve is operating.
Read the bypass setting directly off the force gauge.
5. If the by-pass setting is not correct, follow steps 6 through 10 to adjust it
6.
Relieve the bypass pressure by retracting the jack about 1”.
7.
Refer to Drawing 50141 Sheet 1
for the location of the bypass valve, adjusting
the screw on the control valve. Loosen the lock nut using a 13mm or adjustable
wrench.
8. Use the 5/32 hex driver provided in the Load Locking Kit to turn the adjusting
screw. Thread the adjusting screw in- (clockwise), to increase the bypass setting.
Thread the adjusting screw out- (counterclockwise), to reduce the bypass setting.
Repeat step t4 o read the new bypass setting.
9. Repeat steps 4-8 until the bypass setting is at the desired level.
10. Tighten the lock nut.
