No fasting is required prior to this test. The test evaluates how your body processes sugar. A high level in your blood may indicate your body is not processing sugar effectively (positive test). If the results of this screen are positive, the woman may have the Glucose Tolerance Test performed.
A valve is a mechanism that opens and closes to control the flow of fluids. In a scientific context, fluids include both liquids and gases â any substance that can flow freely â and valves may use either. Valves control fluid flow in motors, plumbing, irrigation, pneumatic and hydraulic systems.
Valve face. (Mach.) that part of the surface of a valve which comes in contact with the valve seat. Valve gear. (Steam Engine) the system of parts by which motion is given to the valve or valves for the distribution of steam in the cylinder. For an illustration of one form of valve gear, see Link motion.