Turbine and Pack Bypass Valve Repair & Overhaul
754751-4 — Turbine and Pack Bypass Valve Repair & Overhaul
| Part number | 754751-4 |
|---|---|
| Nomenclature | Turbine and Pack Bypass Valve |
| Manufacturer | Hamilton Sundstrand |
| Aircraft make | Hamilton Sundstrand |
| Aircraft model | R70 |
| Capability | Pneumatic Valves |
FAA & EASA Part 145 repair & overhaul. We'll confirm turnaround and pricing.
Added to your quote. View quote →
Component Overview
A turbine and pack bypass valve is a pneumatic control valve in an air conditioning pack that regulates how much process air is routed through versus around the cooling turbine, modulating pack outlet temperature and protecting the air cycle machine during transient or low-demand conditions. By diverting a portion of airflow around the turbine, it controls cooling output and prevents turbine overspeed or overcooling, functioning within the system's pneumatic-valve capability. The valve typically combines a butterfly or poppet element with pneumatic or electro-pneumatic actuation and a control head. Degradation modes include actuator diaphragm and seal deterioration, butterfly-shaft bushing wear, seat erosion and leakage, spring fatigue, and contamination causing sticking or sluggish response. Out-of-tolerance scheduling, internal leakage, and erratic positioning drive overhaul, recalibration, and functional testing.
Aircraft Application
Part number 754751-4 (Turbine and Pack Bypass Valve) is installed on the Hamilton Sundstrand R70. QTC supports operators and MROs servicing this platform with certified repair and overhaul.
Our Repair Capability
QTC repairs and overhauls 754751-4 to the original manufacturer's specifications under our FAA and EASA Part 145 approvals. Our team — including former OEM pneumatic & air management engineers — performs teardown, inspection, cleaning, component replacement, functional testing, and certification, returning a serviceable unit with the appropriate airworthiness release. We also develop repairs for rejected and beyond-economic-repair (BER) hardware.
Related Parts
Other turbine and pack bypass valve part numbers we repair — view all Turbine and Pack Bypass Valve parts →
Frequently Asked Questions
Can QTC repair part number 754751-4?
Yes. 754751-4 (Turbine and Pack Bypass Valve) is within QTC's FAA & EASA Part 145 repair and overhaul capability. Request a quote to confirm current turnaround and pricing.
What aircraft is part 754751-4 used on?
754751-4 is used on the Hamilton Sundstrand R70.
What condition does QTC accept for 754751-4?
QTC accepts serviceable, unserviceable, and beyond-economic-repair (BER) units for evaluation. Our engineers determine the most cost-effective repair path after incoming inspection.
What is the typical turnaround time for turbine and pack bypass valve repair?
Turnaround depends on repair scope and material availability. Contact QTC for a current estimate.
Request a Quote for 754751-4
Send us the part number and condition and our engineers will respond with repair scope, turnaround, and pricing.