It was delayed four times because of concern over shuttle valves.

The basic structure of a shuttle valve is like a tube with three openings; one on each end, and one in the middle.

When the compressor is operated the shuttle valves direct air to open the brake shoes.

Shuttle valves provide a logical or function.

Two shuttle valves in the pressure lines prevent fluid feedback between the pilot's and copilot's pedals.

A shuttle valve has several applications including:

The flight to the international space station was originally set for mid-February, but was delayed four times because of concern over critical shuttle valves.

A shuttle valve is a type of valve which allows fluid to flow through it from one of two sources.

Generally a shuttle valve is used in pneumatic systems, although sometimes it will be found in hydraulic systems.

When the compressor pressure is re-established, the shuttle valve shifts back and seals off the standby system until needed again.

Four additional shuttle valves connect the pneumatic system to the brake system for emergency braking.

In systems with multiple loads the load sensing line must be connect to all loads with the use of shuttle valves.

A pressure regulator delivers air at 33 bar, through a shuttle valve that pressurised first the catalyst tanks and then the propellant tank.

I can recall, when apprentice, drilling the shuttle of a Weirs shuttle valve on a pillar drill in the fitting shop.

Shuttle valves automatically connect the higher pressure inlet to the outlet while (in some configurations) preventing flow from one inlet to the other.

This consists of: a modified shuttle valve to replace the standard shuttle valve supplied.

Winch brake circuit: a shuttle valve provides brake control in pneumatic winch applications.

When the control valve is centered, the brake cylinder is vented through the shuttle valve, and the brake shoes are allowed to close.

If the compressor fails, the standby tank-regulated to slightly under the compressor supply-will shift the shuttle valve and take over the function.

The continued use of shuttle valve control via hydraulics has enabled us to retain piloted hydraulics as a secondary control mechanism.

Standby and emergency systems: compressor systems requiring standby or purge gases capability are pressure controlled by the shuttle valve.

(AP) - NASA has resolved a space shuttle valve problem and is aiming for a Friday night launch of Discovery.

Whilst performing an aerobatic manoeuvre, the shuttle valve in the engine oil system became stuck in the inverted position causing a reduction in the engine oil pressure.

Wiebel manufactures parts including activators, shuttle valves, landing gear components and regulator relief valves for other companies such as Goodrich, Orenda and Atlantic Turbines.

Shifting the four-way valve to either extreme position applies the air pilot through the shuttle valve, holding the two air-operated valves open and applying oil under air pressure to the corresponding side of the cylinder.