MIL-DTL-20176G
4.6.9 Flexibility.
4.6.9.1 Class 1. A length of hose selected from the lot shall be laid out on a surface and forced
into a curve drawn with a radius as specified in table III. The curved section shall attain the
curvature without kinking or flattening. Nonconformance to 3.6.3.1 shall constitute failure of this
test.
4.6.9.2 Class 2. A 50-foot (15 240 mm) hose assembly selected from the lot shall be wound
without a reel into a tight coil having a 3.25-foot (991 mm) diameter at a temperature of
60 °F ± 10 °F (16 °C ± 6 °C) (see 3.6.3.2).
4.6.10 Properties of rubber components. The properties of rubber components, except the
swelling in testing oil of the friction rubber on the reinforcing fabric, shall be determined on
longitudinal specimens prepared from the hose section obtained in accordance with 4.6.3. After
separating and buffing, smooth the tube and cover samples shall be permitted to rest not less than
30 minutes before preparing test specimens. The swelling in testing oil of the friction rubber shall
be determined using a vulcanized sample of the rubber friction used to impregnate the fabric
reinforcement. The sample shall be 6 by 6 inches (152 by 152 mm) by 0.08 ± 0.01-inch
(2 ± 0.3 mm), and shall be of the same composition and an equivalent cure as the friction used in
the hose. Nonconformance to the requirements of table I shall constitute failure of the tests.
4.6.10.1 Initial physical properties. Initial tensile strength and ultimate elongation shall be
determined by ASTM D 412 using specimens cut with die C.
4.6.10.2 Physical properties after immersion. Tensile strength and ultimate elongation shall be
determined after being subject to ASTM IRM903 Oil (formerly ASTM Oil No. 3) for 70 hours at
212 °F ± 4 °F (100 °C ± 2 °C) in accordance with the method specified in ASTM D 471. The
change in tensile strength shall be based on the original cross-section area of the sample.
4.6.10.3 Physical properties after oven aging. The tensile strength and ultimate elongation after
oven aging shall be determined in accordance with ASTM D 573, using specimens cut with
die III, except that the aging period shall be 70 ± 0.25 hours at 212 °F ± 4 °F (100 °C ± 2 °C).
4.6.10.4 Volume change after immersion. The change in volume in percent of the original
volume, after immersion shall be determined on samples of the tube, cover, and friction material.
Sample shall be immersed in ASTM IRM903 Oil (formerly ASTM Oil No. 3) for 70 ± 0.25 hours
at 212 °F ± 4 °F (100 °C ± 2 °C) in accordance with the method specified in ASTM D 471.
4.6.10.5 Initial adhesion. The adhesion of the tube and cover to the reinforcement, and of the
plies of reinforcement to each other, shall be determined in accordance with Machine Method of
ASTM D 413 and shall meet the requirement of 3.3.2.
10
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business