The U.S. aircraft register, updated daily
Parts

Disc Valve

No failure report names the disc valve. 1 FAA approvals let 1 company make a replacement disc valve, Allen Aircraft Products holding the most (1).

Approved replacement parts 1 parts manufacturer approvals

A parts manufacturer approval (PMA) lets a company other than the aircraft's maker make a disc valve and sell it as an approved part for the models named. These are the companies holding such approvals for a disc valve:

MakerPartReplacesFitsGrantedStatus
Allen Aircraft ProductsDisc Valve 12C112-1Israel Aircraft Industries MS29521-12AGulfstream Galaxy 1125 ASTRA ASTRA SPX2000-07-09current

Sources: the FAA's service difficulty reports since 1995 (a report is a part that failed and was fixed, as filed by an airline, repair station or owner; the count shows reporting as much as reliability) and the parts manufacturer approvals in the FAA's Dynamic Regulatory System. The part name is the reporters' and the approval holders' own words, reduced to the first plain words so that spellings meet.