What does an isolation valve do?

What does an isolation valve do?

Isolation valves are devices that isolate a valve’s actuation mechanism from the media being moved. They can be configured as simple 2-way devices or as multi-port selector/diverters, and are typically used in applications where a simple on/off function is required without the need to gradually modulate flow.

What is aircraft isolation valve?

Valves in the fuel or hydraulic systems to separate and isolate subsystems in case of any failure. Similarly, in some aircraft, the hydraulic-isolation valve isolates the main systems, like those lowering the undercarriage and the flaps, from the operation of other hydraulically operated systems in case of any leaks.

How is landing gear retracted?

Retractable Landing Gear Functionality: A hydraulic landing gear retraction system utilizes pressurized hydraulic fluid to actuate linkages to raise and lower the gear. When the switch is moved to the UP position, hydraulic fluid is directed into the gear up line.

How does a landing gear system work?

A free-fall or gravity drop system uses gravity to deploy the landing gear into the down and locked position. To accomplish this the pilot activates a switch or mechanical handle in the cockpit, which releases the up-lock. Gravity then pulls the landing gear down and deploys it.

Can control valves be used for isolation?

Check valves, control valves and relief valves are not acceptable as isolation devices. Types of valve that can be used for single-valve isolation include: gate, ball, plug, and needle.

Is it easy to fit an isolation valve?

Fitting an isolation valve is a fairly simple process as long as you know what’s involved. if you want to remove a radiator to decorate behind it and you have isolation valves fitted to the pipes, it’s just a simple matter of turning the valve or valves to off, disconnecting them and then moving the radiator.

Can Ball Valves be used for isolation?

When the valve is open the lever handle should align with the pipe or flow and is perpendicular to the pipe when it is closed. Ball valves (as described) should only be used for isolation.

What is the best type of valve to use for isolation?

Gate valves, ball valves and plug valves are generally considered to provide tight and effective shut-off. Globe valves and Butterfly valves may not be tight shut-off due to wear on the plug or the seat, or due to their design, and may not be appropriate to provide effective isolation.

How does the landing gear isolation valve work?

The landing gear isolation valves will not close or open unless the pressure in that system is at least 100 psi. When the LG hyd isol vlv 1 switch is positioned to open , it allows hydraulic system 1 source pressure to the main landing brake control valves and to the normally closed extend valve.

Which is an example of landing gear retraction?

The correct operation of any aircraft landing gear retraction system is extremely important. Figure 4 illustrates an example of a simple large aircraft hydraulic landing gear system. The system is on an aircraft that has doors that open before the gear is extended and close after the gear is retracted.

How does the landing gear extension system work?

The emergency extension system lowers the landing gear if the main power system fails. There are numerous ways in which this is done depending on the size and complexity of the aircraft. Some aircraft have an emergency release handle in the flight deck that is connected through a mechanical linkage to the gear uplocks.

How does a manual gear retraction system work?

Manual systems work through direct linkage from the cockpit control handle, or lever to the individual gear legs using gears, universal joints and torque tubes. To aid in retracting the main landing gear, large springs (usually garage door springs) are hooked into the linkage.