TB 55-4920-428-35
12. Pressure Gages.
a. Performance checks.
NOTE
Hydraulic oil MIL-M-5606 used in TI and Hydraulic oil MIL-L-7870A
used in dead weight tester are not compatible. TI pressure gages will have
to be cleaned out before and after calibration. If tee connectors are remov-
ed from TI pressure gages extreme care should be taken when tightening
and mounting gages back in hydraulic unit. (Position of tee connectors
should be observed when removing from mounting holes.)
(1) Observe that all TI switches are OFF and valves are in CLOSED position.
(2) Set TI SHUTOFF to OPEN.
(3) Remove the 12 (HEX) screws from TI panel and pull out hydraulic unit.
(4) Disconnect TI low pressure gage (0 - 600 psi) from hydraulic lines and remove from hydraulic
unit. (Remove front panel cover around gage for excess to mounting bolts.)
(5) Connect dead weight tester (A7) to the TI low pressure gage.
(6) Place enough weights (supplied with pressure gage tester) on the appropriate pressure piston to
obtain a pressure equal to 50 psi.
To avoid scoring the piston guide and damage to the dead weight
cylinder, constantly rotate the weights and piston when inserting or
removing the piston or when applying pressure. Do not remove weights
when pressure is applied to dead weight cylinder.
(7) Using the hand pump, apply pressure to dead weight cylinder until the piston is approximately
9/16 inch above the dead weight cylinder. TI low pressure gage will indicate between 45.0 and 55.0 psi.
(8) Visually inspect the equipment connections for leakage. If leakage appears, release pressure
and tighten or seal connections as required.
(9) Place appropriate weights on the dead weight tester to provide normal pressure correspon-
ding to 100, 200, 300, 400, and 500 psi. TI low pressure gage will indicate within + 5 psi of nominal
pressure generated by the dead weight tester for each indication.
(10) Disconnect dead weight tester from TI low pressure gage and reinstall in hydraulic unit.
(11) Disconnect TI high pressure gage (0 - 5000 psi) from hydraulic lines and remove from
hydraulic unit and connect dead weight tester to the TI high pressure gage. Remove front panel
cover around gage for excess to mounting bolts.)
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