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(888) 312-8812 Login SignupThe Williams Controls WM778A Air Brake Pressure Protection Valve helps portion air supply to auxiliary circuits by opening only after system pressure reaches its 70-psi threshold. Its 1/4" NPT configuration suits brake layouts where accessory functions must stay isolated until the primary brake reservoir reaches safe pressure levels. The valve’s internal layout helps keep secondary devices from drawing air too early, supporting consistent system order during cold starts or extended staging. Its compact form also fits neatly into tight brake-control clusters, and the threaded ports allow straightforward replacement without modifying the surrounding plumbing. If a vehicle depends on structured air management that prioritizes brake pressure first, the Williams Controls 118181 fits the task with steady performance.
| Port | 1/4" NPT |
| Nominal Pressure | 70 psi |
| Brand | Part Number |
|---|---|
| Euclid | E4324 |
| Phillips | 801002 |
| Velvac | 032086 |
| Williams Controls | 118588 |
| Muncie | 31M15759 |
| Ridewell Corp | 1234761B000 |
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