Test Procedures for Determining Air Brake Valve Input-Output Characteristics
J1859_198904
This SAE Recommended Practice establishes uniform test procedures for determining input-output characteristics for those pilot-operated and mechanically actuated, modulating-type valves and through-type valves used in the service brake control system.
Input-Output Characteristics
Crack (opening) pressure or force
Pressure differential (input-output)
Hysteresis (increasing-decreasing pressure)
Pilot-Operated Modulating-Type Valves
Relay Valve
Ratio relay valve
Decaying ratio relay valve
Booster relay valve
Relay Valve with two-way check valve
Relay Emergency
Mechanically Actuated Modulating-Type Valves
Dual service brake valve
Through-Type Valves
Quick release valve
Tractor protection valve
Limiting valve
Gladhand with quick release valve
Modulator Valve (ABS)
Tractor protection valve with two-way check valve(s)
Purpose
This document is intended as a guide toward standard practice but may be subject to frequent change to keep pace with experience and technical advances, and this should be kept in mind when considering its use. This document provides a uniform definition of input-output characteristics of pneumatic valves designed to operate in 862 kPa (125 psi) nominal pressure air brake systems and establishes uniform test procedures to determine these characteristics. This document serves as a supplement to SAE J1409.