The U.S. aircraft register, updated daily
Parts

Valve System

No failure report names the valve system. 3 FAA approvals let 1 company make a replacement valve system, Sargent Aerospace holding the most (3).

Approved replacement parts 3 parts manufacturer approvals

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

MakerPartReplacesFitsGrantedStatus
Sargent AerospaceValve System Steering 40001-005LASC 672435-127Lockheed L-1011-385-1, -385-1-14, -385-1-151993-01-18current
Sargent AerospaceValve System Steering 40001-502LASC 672435-119Lockheed L-1011-385-1, -385-1-14, -385-1-151993-01-18current
Sargent AerospaceValve System Steering 40001-004LASC 672435-121Lockheed L-1011-385-1, -385-1-14, -385-1-151993-01-18current

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.