( f ) C o r r o s i o n . The external surfaces of air lines should be protected
by corrosion-proof paint or by adequate covering.
( g ) Operation of Associated Equipment. Ensure correct operation of
associated equipment, such as moisture traps, strainers, pressure reducing
s t a t i o n s , dehumidifiers, and auxiliary equipment, which are addressed
elsewhere in this manual.
I n s p e c t the following items.
2.2 Yearly Inspection of Aboveground Systems.
(a) Check for corrosion, leakage, loose joints, and damaged or missing
supports of piping systems.
( b ) Settling or shifting of poles, hangers, or other supporting
members. This can be determined by checking the grade of the lines.
( c ) Check valves for leakage, corrosion, defects in stems, packing
glands, handwheels, seats, bodies, flanges, and gaskets.
( d ) Valve pits for clogged vents, structural damage, missing covers, and
accumulation of dirt and debris.
(e) Condition of flanged fittings.
( f ) Condition of expansion joints, if any.
(g) Condition of hangers, guides, supports, and anchors.
( h ) Condition of traps, s t r a i n e r s , dehumidifiers, and moisture
( i ) Condition and adjustment of pressure reducing stations.
( j ) Setting of relief and safety valves.
( k ) Condition of air receivers.
( 1 ) Condition and calibration of instruments.
2.3 Inspection of Underground Systems. T h e applicable instructions in
paragraph 2.2 are also valid for inspections of underground systems. Refer to
i n f o r m a t i o n on inspection of steam distribution systems (ignore instructions
r e g a r d i n g insulation and telltales).
3 HYDROSTATIC TESTS. Test the distribution system with water pressure
f o l l o w i n g major repairs involving pipe welding or making up joints.
4 OVERHAUL AND REPAIRS.
Refer to chapter 3, section 4, paragraphs 3.1