3.9 Air hose. The air hose shall be the commercial heavy duty type 5/16 inch ID, with
minimum rated working pressure of not less than 200 psi. Unless otherwise specified (see 6.2),
the hose shall be not less than 50 feet long. Air hose couplings shall be internal swivel fitted,
having a l/4-inch, standard, straight-pipe thread and a 30-degree tapered seat and shall be fitted at
one end with an inflater gauge conforming to GG-G-91, type III, style 3.
3.10 Intake air filter and silencer. The compressors shall be provided with a dry-type
combination intake air filter and silencer and shall have a rainshield or a similar protective
3.11 Electromagnetic interference. Unless otherwise specified (see 6.2), the electromagnetic
interference requirements shall be in accordance with MIL-STD-461, group II of class C3.
3.12 Lubrication. All surfaces requiring lubrication shall be provided with a means of
3.12.1 Lubricants. The procedure for the selection of lubricants shall be in accordance with
MIL-STD-838, section 5. Lubricants selected shall be in accordance with MIL-HDBK-113,
chapter 2. When the specification of the lubricant selected includes a requirement for a Qualified
Products List (QPL), the lubricant supplied shall be from a source that is listed on the applicable
QPL (see 6.4).
3.12.2 Lubrication fittings. Lubrication fittings shall conform to MIL-F-3541, type I, II or
III. Fittings shall be located in protected positions. Fittings shall be accessible to a grease gun
conforming to MIL-G-3859, type II. Accessibility to fittings shall be provided without the
removal or adjustment of accessories or parts. Panels and plates equipped with hand-operable,
quick-disconnect fasteners may be removed to provide accessibility to lubrication fittings.
3.12.3 Pressure-release device. A pressure-release device shall be provided where the use of
pressure lubricating equipment will damage grease seals or other parts.
3.12.4 Enclosures with integral reservoir of lubricant. Enclosures, such as gear cases and
transmission housings which contain a reservoir of lubricants for lubrication of the parts
enclosed, shall be equipped with dipsticks, check plugs not less than 1/2-inch pipe size, or sight
gauges to determine the level of the lubricant. Each enclosure shall be equipped with a drain
plug. Each enclosure shall be equipped with a means for filling the enclosure with lubricant.
The drain plug shall be located so that removal of the drain plug will result in complete drainage
of the lubricant from the enclosure. Drain outlets shall be located to allow lubricant to drain to a
suitable container when the compressor is in its normal position. Integral tubes or troughs may
be used to convey drained lubricants from the drain plug to the drain outlet. Accessibility to the
drain plug, the filling means, and the lubricant-level checking device shall be obtained without
the removal or adjustment of accessories or parts. Engine-housing side panels and plates
equipped with hand-operable, quick-disconnect fasteners may be removed to facilitate this