- cross-flow valve
- A valve meant to bypass hydraulic fluid from the landing gear upline to the downline when the landing gear is being extended. The weight of the landing gear, when it is released, is so great that it falls very rapidly. Under these conditions, hydraulic fluid cannot fill the space behind the moving piston in the landing-gear actuating cylinder; hence, pressure is increased in the upline and on the opposite side of the piston. By having a cross-flow valve in the system, fluid is permitted to flow from the upside of the piston to the downside and thus allow the landing gear to drop with an even motion and with more ease. Cross-flow valves may be manually or automatically operated. The former is used only during the emergency operation of the landing gear, whereas the latter is used for the normal operation of landing gear.
Aviation dictionary. 2014.
Look at other dictionaries:
cross-feed cock — A cock in the aircraft fuel system plumbing to regulate the flow of fuel from one tank to another. The system that permits the engine to be fed fuel from any of the tanks is called a cross feed system. The fuel is regulated, in this case, by a… … Aviation dictionary
Valve — This article is about the flow control device. For the game developer, see Valve Corporation. For the electronic component, see Vacuum tube. For other uses, see Valve (disambiguation). These water valves are operated by handles. A valve is a… … Wikipedia
Cross-linked polyethylene — PEX redirects here. For other uses, see Pex (disambiguation). Cross linked polyethylene, commonly abbreviated PEX or XLPE, is a form of polyethylene with cross links. It is formed into tubing, and is used predominantly in hydronic radiant heating … Wikipedia
Artificial heart valve — An artificial heart valve is a device implanted in the heart of a patient with heart valvular disease. When one of the four heart valves malfunctions, the medical choice may be to replace the natural valve with an artificial valve. This requires… … Wikipedia
Choked flow — is a compressible flow effect. The parameter that becomes choked or limited is the velocity or the mass flow rate. Choked flow is a fluid dynamic condition associated with the Venturi effect. When a flowing fluid at a given pressure and… … Wikipedia
Check valve — Tilting disc inconel check valve … Wikipedia
Mitral valve — Anterior (frontal) view of the opened heart. White arrows indicate normal blood flow. (Mitral valve labeled at center right.) … Wikipedia
Directional control valve — Directional control valves are one of the most fundamental parts in hydraulic machinery. They allow fluid flow into different paths from one or more sources. They usually consist of a piston inside a cylinder which is mechanically or electrically … Wikipedia
Aortic valve area calculation — is an indirect method of determining the area of the aortic valve. The calculated aortic valve orifice area is currently one of the measures for evaluating the severity of aortic stenosis. A valve area of less than 0.8 cm² is considered to be… … Wikipedia
Bag valve mask — A bag valve mask (also known as a BVM or Ambu bag) is a hand held device used to provide ventilation to a patient who is not breathing or who is breathing inadequately. The device is a normal part of a resuscitation kit for trained professional,… … Wikipedia