Identification. Teflon hose and hose assemblies, and fittings are identified in the following paragraphs.
Size. Bulk Teflon hose manufactured to requirement of MIL-H-27267 shall conform to
dimensions referenced In table 4-21.
(b) Appearance and markings. Hose construction shall be a smooth bore (firm, waxy feeling) inner
tube covered with corrosion-resistant steel wire braid. Hose shall be Identified by an identification band spaced at 3-foot
intervals, marked with specification number and manufacturer's code number as listed in Federal Handbook H4-1.
Fittings. All end fitting assemblies conforming to MIL-F-27272 are identified by an attached
cardboard disc marked with MS number, manufacturer's part number, name or trademark. All component parts of end
fitting assemblies conforming to referenced specification are impression stamped with MS numbers as listed in
paragraph 3 of the referenced specification.
To eliminate the possibility of hose failure by mismatch of similar type fittings, check each Item of the
assembly carefully to ensure that it conforms to the proper Military Standard (MS) prior to the assembly of
Hose assemblies. Factory fabricated Teflon hose assemblies are identified by a permanently
attached metal band marked with MIL-H-25579, operating pressure in psi, assembly part number, date of proof test and
hose manufacturer's code number. Locally manufactured or tested Teflon hose assemblies shall be identified by a metal
band made from Federal Specification QQ-A-250/8, 5052-0 aluminum alloy, 0. 020 Inch thick, 0 75 Inch wide, In
accordance with figure 4-42. The markings on the band may be impression stamped, etched or engraved to include date
of pressure test, Federal stock number or part number, operating pressure, and depot or unit code or name. If the
pressure test date is more than one year prior to installation in the aircraft or system, the assembly shall be retested and
banded prior to installation. Original manufacture date of all retested hoses shall be brought forward onto the new band,
Handling. Exercise extreme care when handling bulk Teflon hose and hose assemblies to prevent
injury to hands from the wire braid ends and damage to hose due to kinking. Kinking results when hose is bent to a
shorter radius than specified in table 4-21 and from twisting during installation. Teflon hose assemblies tend to conform
to the shape of installed positions on hot fluid lines; therefore, exercise care in handling and removing these lines to
prevent straightening which could result in kinking. A kinked Teflon hose must not be installed since this will result in a
failure at point of kink
Maintenance Inspection and Replacement Criteria. Inspect installed Teflon hose assemblies for
evidence of deterioration due to wire fatigue or chafing at the specified periods prescribed in the applicable aircraft
inspection or maintenance manuals and replace when any of the following conditions are found.
Leaking. Static leakage exceeding 1 drop per hour.
Excessive Wire Damage. Excessive wire damage consists of 2 or more broken wires in a single
plait, or more than 6 broken wires per assembly or per lineal foot whenever assemblies exceed 12 inches in length.
Broken wires where kinking is suspected are evidence by sharp dents or twisted wire braid.
Crossed reinforcing or random broken wires is not cause for replacement
Distortion. Any evidence of abrasion, kinking, distortion, bulging, or sharp bends.
Hoses from stock. Hose assemblies drawn from stock shall be inspected for defects such as
mishandling damage and proper banding Hoses that are suspected to have damage or are not banded will be proof-
tested and banded.
Hoses removed from aircraft. Hose assemblies removed from an aircraft shall be inspected,
proof tested, and banded.
Hose Assemblies and Pump Pressure Lines. Clean hose assemblies removed from installation for
reasons other than cited in paragraph 4-51 (8) and pump pressure lines removed by replacement schedule in