is it really effective against a hydraulc leak thru pin hole.
2006-09-12 16:50:23 · 4 answers · asked by canard63 1 in Cars & Transportation ➔ Aircraft
A Hydraulic Fuse or any fuse in a liquid system is in case of pressure overload so it has a way to vent instead of blowing a component.
A Check Valve is a component that makes sure there is no reverse flow. Like say a line blows, the check valve prevents any fluid upstream from coming back and venting form the leak area.
So in layman's terms a hydraulic fuse is just like an electrical circuit breaker. It is meant to go off so no internal component damage will occur in case of a power spike, in this case a pressure surge.. For the most part they can be reset mechanically.
In either case Michael_I is also correct. There are some flow limiter fuses installed in hydraulic systems to prevent massive fluid loss. I know the brake systems on some aircraft have them but none directly on the landing gear, as in the extention and retraction actuators.
Now are they effective vs pinhole leaks? nope. Pinhole leaks will not set either a fuse or a check valve off. All you get is a leak and a nice fine mist spray which gets everything all full of fluid.
2006-09-12 17:14:20 · answer #1 · answered by Tegeras 4 · 2⤊ 0⤋
A hydraulic Fuse is also called a lockout deboost valve. It has nothing to do with a system overload, that's what relief valves are for. The Hydraulic fuse is meant to protect against excessive fluid loss, most often these lockout-deboost valves are used in a Hydraulic Brake system just in case there is a leak on the brake side of the valve in order to keep from dumping an entire system of fluid onto a runway.
2014-01-29 21:59:34 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Fuse (hydraulic)
From Wikipedia,
In hydraulic systems, a fuse is a component which prevents the sudden loss of hydraulic fluid pressure. It is a safety feature, designed to allow systems to continue operating, or at least to not fail catastrophically, in the event of a system breach.
The term "fuse" is used here in analogy with electrical fuses which perform a similar function.
Hydraulic systems rely on high pressures (usually over 7000 kPa) to work properly. If a hydraulic system loses fluid pressure, it will become inoperative and components such as actuators may collapse. Obviously this is an undesirable condition in safety-critical applications such as aircraft or cranes. Hydraulic fuses help guard against catastrophic failure of a hydraulic system (for instance, by line breakage or component failure) by automatically isolating the defective branch.
When a hydraulic system is damaged, there is generally a rapid flow of hydraulic fluid towards the breach. Most hydraulic fuses detect this flow and seal themselves if the flow exceeds a predetermined limit. There are many different fuse designs but most involve a passive spring-controlled mechanism which closes when the pressure differential across the fuse becomes excessive.
Hydraulic fuses are not a perfect solution to fluid loss. They will probably be ineffective against slow, seeping loss of hydraulic fluid, and they may be unable to prevent fluid loss in the event of a catastrophic system failure involving multiple breaches to hydraulic lines. Also, when a fuse activates it is likely that the system will no longer function as designed.
Depending on the system, hydraulic fuses may reset automatically after a delay, or may require manual re-opening.
2006-09-12 23:56:27 · answer #3 · answered by michael_lovin 5 · 3⤊ 0⤋
Just some more info, on the 707 they are called Lockout-Deboost Valves. The lockout portion is the hydro fuse. The deboost lowers system pressure from 3000 psi to 1000 psi for the brakes.
2006-09-13 09:08:50 · answer #4 · answered by sc0tt.rm 3 · 0⤊ 0⤋