This SAE Aerospace Standard (AS) establishes Type classification for those hose assemblies commonly used in aerospace fuel, lubricating oil, and hydraulic fluid systems.

Purpose:

The purpose of this document is to create a common Classification (Type) system for the aforementioned hose assemblies. This is to facilitate determining comparability within a Type, offer a consolidated listing of active hose assembly types with performance references including fire resistance properties, and incorporate periodic fire testing of fire proof/resistant hose assemblies (see also Section 6).

Product Classification:

Hose assemblies are classified (Type) (see Figure 1 for examples).

Basic Performance (Using Roman Numerals): Each basic type is identified by performance in accordance with a military, SAE or other industry specification(s) based upon pressure rating, temperature rating, and application(s).

Fire Resistance (if applicable):

Suffix using lowercase Letters "a", "b", or "s" to indicate fluid flow rate:

a. "a" indicates a fluid flow rate of 5 × ID² [generally fuel and lube oil applications]

b. "b" indicates a fluid flow rate of 1 × ID² [generally hydraulic (pressure and return) applications]

c. Special "s" designates no flow but fluid filled

d. No suffix indicates no requirement/qualification for fire resistance

NOTE: TSO-C75 lists various flow rates based on type, size, and pressure (see 3.2).

Suffix using upper case letters "A" or "B" to indicate fire test duration requirement (if applicable):

a. "A" indicates AS1055 Class A (5 min) fire resistant (same as fire resistance of TSO-C53a and TSO-C75)

b. "B" indicates AS1055 Class B (15 min) fireproof

c. No suffix indicates no requirement/qualification for fire resistance

Identification must include, as minimum:

a. AS150 "Type___" (per Table 1)

b. Flow "a", "b", or "s", if fire resistant (If applicable)

c. Duration code "A" or "B" (If applicable)

d. Example "Type laB"

A further special case is a single performance (pressure rating) standard, such as AS1227 or MIL-DTL-25579, with two or more temperature classes. The temperature limit must be stated.

Application:

Section 6 describes the shortcomings of current classification systems in adequately providing for the variety of hose (assembly) materials, operating pressures, temperatures, and fire resistance.