RWH ROTARY SCREW COMPRESSOR UNITS
MAINTENANCE
070.620-IOM (DEC 12)
Page 39
SHUTDOWN DUE TO IMPROPER OIL
PRESSURE (HIGH STAGE and BOOSTER)
The compressor must not operate with incorrect oil
pressure.
1. Refer to CONTROL SETUP - "OIL SETPOINTS DISPLAY"
in publication 090.022O.
MOTOR and BARE COMPRESSOR
REPLACEMENT
Refer to publication 070.660SM.
SAE STRAIGHT THREAD O-RING FITTINGS
ASSEMBLY PROCEDURE
When performing maintenance or replacing the compres
sor, the hydraulic tubing may need to be removed and
reinstalled. The following procedure outlines the proper
installation of SAE straight thread ttings to SAE straight
thread ports.
The male and female ends of SAE straight thread Oring
ports have UN/UNF straight threads. An elastomeric Oring
is tted to the male end. On assembly, the Oring is rmly
sandwiched between the angular sealing surface of the fe
male port and the shoulder of the male end. Sealing is thus
affected and maintained by the Oring compression which
results from the clamping force generated by the tightening
action. The straight threads do not offer sealing action; they
provide the resistance (holding power) for service pressure.
1. Inspect components to ensure that male and female port
threads and sealing surfaces are free of burrs, nicks and
scratches or any foreign material.
2. If the Oring is not preinstalled to the tting on the male
end, install the proper size Oring.
3. Lubricate the Oring with a light coating of system oil or
petroleum jelly.
4. Screw the tting into the female port until the hex at
contacts the port face. Light wrenching may be necessary.
5. Tighten to the appropriate torque value shown in the
Assembly Torque Table.
ASSEMBLY TORQUE TABLE
Straight and Adjustable Fittings or Plugs (steel)
Fitting Size SAE Port Thread Size
Assembly Torque
Inch lb Foot lb
2 5/16 – 24 65 ± 5 5.5 ± 0.5
3 3/8 – 24 130 ± 10 11 ± 1.0
4 7/16 – 20 170 ± 10 14 ± 1.0
5 1/2 - 20 260 ± 15 22 ± 1.0
6 9/16 – 18 320 ± 20 27 ± 2.0
8 3/4 - 16 500 ± 25 42 ± 2.0
10 7/8 – 14 720 ± 30 60 ± 2.5
12
1Z\zn – 12
960 ± 50 80 ± 5.0
16
1B\zn – 12
1380 ± 75 115 ± 6.0
20
1B\, – 12
2700± 150 225 ± 12.0
24
1M\, - 12
3000 ± 160 250 ± 12.0