Anti-Ice Valves Repair & Overhaul

Anti-ice valves control the flow of hot engine bleed air used to protect ice-prone surfaces from accumulation. Routing high-temperature bleed air to the wing leading edges, engine cowls, nacelles, and inlet leading edges, these valves are central to a flight-critical ice protection function: maintaining a thermal barrier that prevents ice formation where it would most degrade aerodynamic performance and engine operation.

The family includes wing anti-ice valves, cowl anti-ice valves, nacelle anti-ice valves, and inlet anti-ice valves, as well as cowl anti-ice PRSOV configurations that combine pressure regulation and shutoff with the anti-ice supply function. Designs generally pair a butterfly or poppet flow element with a pneumatic or electro-pneumatic actuator, allowing the valve to open the hot-air supply on demand and to close positively when anti-ice is not required.

Because these valves operate in a severe high-temperature, high-cycle environment and serve a safety-critical role, repair and overhaul are essential. Seat and seal wear, actuator and solenoid deterioration, contamination, and spring fatigue can cause leakage, slow or incomplete actuation, or failure to deliver adequate hot-air flow. Returning the valve to correct opening, closing, and flow performance preserves reliable ice protection across the flight envelope.

QTC overhauls anti-ice valves using a structured MRO process appropriate to their safety-critical role. The valve and its actuator are inspected and disassembled, with the flow element, seat, shaft, bushings, springs, seals, and any solenoid or regulator components evaluated against serviceable limits. Worn seats, seals, and bushings are replaced, and the actuator and any regulator or shutoff section are overhauled to restore correct operation in the high-temperature bleed-air environment.

Following reassembly, the unit is recalibrated where applicable and functionally tested to verify positive opening and closing, correct flow, and acceptable leakage performance. Flow, leak, and functional checks confirm that the valve delivers reliable hot-air control before it is certified and returned to service. All work is completed against the applicable maintenance data under QTC's FAA and EASA Part 145 approvals.