 |
|||
|
|
|||
| ||||||||||
|
|  MIL-C-52980B
3.19.3 Pressure tubing and fittings. All pressure tubing and fittings shall be rated to
withstand 1-1/2 times their normal working pressure.
3.19.4 Drive. The drive shall consist of matched multiple V-belts and grooved pulleys on
the power unit and compressor unit. Except for the winterized compressor (see 3.25.7), all drive
belts shall conform to ZZ-B-190. A means for belt removal and adjustment shall be provided.
3.20 Type II, rotary.
3.20.1 Compressor. The type II compressor shall deliver the capacities of free air specified
in table I at a pressure of 175 psig as determined by the ASME Performance Test Code 9. The
components of the compressor shall be balanced so that when the compressor is operating in
conjunction with the gasoline engine, vibration shall be minimized. The compressor shall not
exceed the contractor's recommended continuous operating speed. The compressor unit shall be
positive displacement and air-oil cooled. A means shall be provided to remove and recover the
oil from the discharge air. When a filter-type separator is used, it shall be accessible for
examination, cleaning and replacement without removal of other parts or components. To
prevent hydraulic lock upon starting, a means shall be provided in the stator assembly to allow
accumulated oil to pass into the sump. A pressure gauge shall be provided between the
compressor unit and the separator discharge to indicate the pressure in the compressor. A
nonreturn valve shall be provided either in the oil separator or in the discharge from the separator
to prevent reverse flow of air from the receiver.
3.20.2 Pressure tubing fitting. All pressure tubing and fittings shall be capable of
withstanding 1-1/2 times their normal working pressure.
3.20.3 Drive. The type II compressor shall be either direct drive or multiple V-belt drive.
The multiple V-belt drive shall conform to 3.19.4. When a direct drive is used, a flexible
coupling shall be installed between the power unit and compressor unit. The mounting base for
the power unit shall have a means for belt removal and adjustment when V-belt drive is used.
3.21 Class 1, tank-mounted. The compressor unit and power unit shall be mounted on a base
attached to the air-receiver tank.
3.21.1 Air-receiver tank. The air-receiver tank for the class 1 compressor shall be of the
horizontal type and shall be constructed in accordance with the ASME Boiler and Pressure
Vessel Code, section VIII. The receiver shall bear the ASME stamp and no welding or other
activation shall be permitted after the receiver has been certified. Unless otherwise specified
(see 6.2), the capacity of the air-receiver tanks for the 5-cfm compressors shall be not less than
60 gallons and for the 15-cfm and 25-cfm compressors shall be not less than 80 gallons. Unless
otherwise specified (see 6.2), the air-receiver tank fittings shall include a globe discharge valve,
a drain cock, and a 0 to 300-psig pressure gauge having 10 psig or smaller increments. The
air-receiver tanks shall include a pressure relief valve conforming to ASME Boiler and Pressure
12
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals