What is the purpose of bypass valve?

What is the purpose of bypass valve?

Controlling pump output. Pressure bypass valves serve to control pressure in a system by diverting a portion of the flow. Typically they bypass fluid from the outlet of a pump back to the reservoir.

What is variable bleed valve?

Variable Bleed Valves are used on all turbine aircraft engines to increase efficiency and prevent possible stalls at starting, idling, and low speed operation. White Flexible Shafts drive the actuation of many of these VBV systems, ringing the engine circumference to drive the opening and closing of the valves.

What is the purpose of variable inlet guide vanes?

Variable Inlet Guide Vanes (VIGVs) regulate airflow into the Low-Pressure Compressor (LPC) to enhance turbine efficiency at part loads.

What do turbine engines use bleed air for?

Bleed air can be used to heat the engine inlets to prevent ice from forming, detaching and being ingested into the engine. Similarly, this warm air can be used to prevent ice build-up on the leading edges of the wings. Bleed air is also sometimes used for starting one of the aircraft’s engines.

How does a cold air intake bypass valve work?

On most systems, the valve installs along the upper portion of the inlet pipe. It shuts down induction at the filter when it becomes submerged. Air is routed through the bypass valve’s external diaphragm to keep water out and air flowing in.

What is the function of the bypass valve on the self contained breathing apparatus?

The Emergency Bypass valve bypasses the pressure demand system of the second stage regulator; it provides a constant flow of air to the inside of the face-piece whether the user is inhaling or not.

Where are the variable bleed valves located?

A variable bleed valve includes a variable bleed valve door disposed in a bleed inlet in transition duct and rotatable about an axis at or near a forward end of door. Valve is operable to open and close a bleed slot open to a booster bleed flowpath located outwardly of transition duct and having an airflow restrictor.

How do variable stator vanes work?

Variable stator vanes permit the angle of incidence of the exiting air onto the rotor blades to be corrected to angles which the rotor blades can tolerate without flow separation. This reduces the angle of incidence at entry to the blades and hence the tendency of them to stall.

Why do some turbine engines use variable inlet guide vanes?

The variable guide vanes (VGV) of gas turbine engines are commonly utilized to expand operating range and to improve efficiency of the compressor. Guiding air flow using the VGVs in the compressor prevents aerodynamic instability by making proper incidence angle to the blades.

What is bleed valve in turbine?

“Bleed valve” is another one of those poor American English terms for a valve which is meant to siphon off a portion of the flow from another system. A GE-design heavy-duty gas turbine employs compressor bleed valves to protect the axial compressor during start-up and shutdown against stalling and surging conditions.

How does a GTE produce engine bleed air?

Customer bleed air (Figure 1), extracted from the compressor’s 16th stage, provides gas turbine anti-icing, prairie and masker air, and start air for the other Gas Turbine Engine (GTE). Customer bleed air passes through the bleed air valve located inside the module. Bleed air then passes through the bleed air cooler.