MIL-DTL-24788A
TABLE III. Sampling for conformance inspections and tests.
Lot Size
Sample Size
5 - 20
5
21 - 100
10
101 - 500
35
501-2000
50
More than 2000
75
4.4 Visual and dimensional examination. Each semi-dry-break, quick-disconnect coupling assembly, male half
(nipple), and strainer shall be thoroughly examined for rough edges and castings, sharp edges where machining has
been performed, and for compliance to 3.3.1.1 and the manufacturer's drawings.
4.5 Test methods. CAUTION: Tests requiring the use of a flammable test fluid should be conducted in an area
where hot work (welding), smoking, and other activities that could produce sparks are prohibited.
4.5.1 Proof pressure. The mated male and female halves of the semi-dry-break, quick-disconnect coupling
assembly shall be subjected to an internal test pressure of not less than 120 PSI for not less than 1 minute using test
fluids specified in 3.3.2. Failure to meet the requirements of 3.10.1 shall be cause for rejection.
4.5.2 Operating force. With the male half (nipple) of the semi-dry-break, quick-disconnect coupling assembly
mounted on a solid support, the female half of the assembly shall be engaged and locked. The female half of the
assembly shall then be unlocked and disengaged. Failure to meet the requirements of 3.10.2 shall be cause for
rejection.
4.5.3 Leakage. The mated male and female halves of the semi-dry-break, quick-disconnect coupling assembly
shall be subjected to internal fluid pressures of minus 4 PSI to plus 4 PSI in 2-PSI increments and from 10 PSI to 60
PSI in 10-PSI increments using test fluids specified in 3.3.2 for positive pressures and air for negative pressures.
The pressures shall be maintained at each increment for not less than 1 minute. Failure to meet the requirements of
3.10.3 shall be cause for rejection.
4.5.3.1 Semi-dry-break leakage. With the male half (nipple) removed from the semi-dry-break, quick-
disconnect coupling assembly, the female half of the assembly shall be connected to a test fluid (see 3.3.2) pressure
source. Five and 60 PSI pressure shall be applied to the inlet of the female half and held for not less than 1 minute.
The outlet of the female half shall be observed for leakage. Failure to meet the requirements of 3.10.3.1 shall be
cause for rejection.
4.5.4 Extreme temperature. Semi-dry-break, quick-disconnect coupling assemblies (male half; 60-mesh
strainer; female half) shall be subjected to fuel resistance and extreme temperature testing as follows:
a.
The outlet of the male half of the semi-dry-break, quick-disconnect coupling assembly shall be connected
to a suitable blank plate to prevent fuel leakage.
b.
The inlet of the female half of the semi-dry-break, quick-disconnect coupling assembly shall be connected
to a 3-foot length of API 1529, Grade 2, Type C, semi-hardwall 3-inch diameter hose. Provisions shall be
made to seal the inlet of the hose during testing.
c.
The test unit (hose; semi-dry-break, quick-disconnect coupling assembly) shall be half filled with test fluid
(see 3.3.2) and placed in a suitable chamber. The temperatures, soak time, and order of testing shall be as
specified in Table IV.
4.5.4.4 Tests after each extreme temperature soak period. At the conclusion of each soak period, the semi-dry-
break, quick-disconnect coupling assembly shall be subjected to several tests at the temperature conditions
prescribed in Table IV. The semi-dry-break, quick-disconnect coupling assembly shall be disconnected and then
reconnected. Following this functional test, the assembly shall be subjected to a positive leakage test (see 4.5.3) (no
negative pressures). Failure to meet the requirements of 3.10.3 shall be cause for rejection.
9
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business