This recommended practice establishes uniform performance requirements for pneumatic valves designed to operate at 125 psi nominal pressure in commercial air brake vehicles. This practice establishes minimum performance requirements for pneumatic valves when tested in accordance with the test procedure outlined in SAE J1409. The performance requirements will include: Input - output performance, Leakage test, Low temperature performance, Elevated temperature performance, Corrosion resistance performance, Endurance testing, and Structural integrity.