MIL-DTL-26521L
3.5.2 Cover material. The cover shall be constructed of a black, ozone resistant and fuel resistant
synthetic rubber material compounded to meet all the requirements of this specification. The cover
material shall be smooth, and free of pitting, blisters, depressions, grooves, holes, cuts, charge marks,
slits, porosity, and foreign material. Wrap impressions are acceptable.
3.5.2.1 Cover thickness. The cover thickness shall be not less than .06 inch (1.5 mm). The
dimensions shall be measured in accordance with 4.6.2.1.
3.5.2.2 Cover tensile and elongation. The cover material shall have a tensile strength of not less
than 1000 psi (6.9 MPa) and an elongation of not less than 200% when tested in accordance with 4.6.2.2.
3.5.2.3 Cover ozone resistance. The cover material shall not show signs of cracking when tested in
accordance with 4.6.2.3 and examined as specified in ASTM D1149.
3.5.2.3.1 Hazardous substances and ozone depleting chemicals. The ozone resistance test (see
4.6.2.3) may contain hazardous chemicals. This test shall be performed in accordance with Federal
regulations and guidelines. For further information about toxic chemicals and hazardous materials lists,
consult the Environmental Protection Agency web database at www.epa.gov/ebtpages/pollutants.html.
3.5.2.4 Cover volume change. The cover material shall not have more than 80% volume change
when tested in accordance with 4.6.2.4.
3.5.2.5 Cover low temperature resistance. The cover material shall not crack when subjected to
-40 ±2° F (-40°C ± 1.1°C) and tested in accordance with 4.6.2.5.
3.5.2.6 Cover material abrasion resistance. The quantity of material abraded shall not exceed 160
3
mm when tested in accordance with 4.6.2.6.
3.5.3 Reinforcement material. The reinforcement material shall be a synthetic yarn, cord, or fabric
that is braided, spiraled, or plied, and free of defects and geometrical irregularities. Two or more layers of
reinforcement laminated between synthetic rubber layers not less than .03 inch (0.8 mm) thick shall be
used in the hose construction. The reinforcement material weave construction shall be such that it will
allow the rubber layer on one surface to flow through the reinforcement and vulcanize with the rubber
layer on the other surface in such a manner as to encapsulate the reinforcement yarns with rubber. The
reinforcement material shall not exist within the liner or cover thickness areas.
3.6 Hose.
3.6.1 Hose inside diameter. The hose inside diameter shall be as specified in table II.
TABLE II. Hose dimensional and physical requirements.
Hose ID
Pressure psi (MPa)
inches (mm)
Maximum
Minimum
Minimum
± .06 (1.5)
Working
Proof
Burst
2.00 (50.8)
225 (1.6)
400 (3)
900 (6)
2.50 (63.5)
225 (1.6)
400 (3)
900 (6)
3.00 (76.20)
225 (1.6)
400 (3)
900 (6)
4.00 (101.6)
225 (1.6)
340 (2)
900 (6)
3.6.2 Length. The length of the hose shall be as specified, with a tolerance of ±1%. The length
measurement shall not include the couplings.
6
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business