This Parker VQ series toggle valve is an inline valve placed directly on a pneumatic line for manual on-off control in moderate pressure and temperature applications. It has female National Pipe Taper (NPT) threaded connections on both ends. It is made of brass for resistance to corrosion and has a PTFE (polytetrafluoroethylene) stem seal for resistance to chemicals and high temperatures. This toggle valve has a maximum operating pressure of 300 pounds per square inch gauge (psig) and an operating temperature range of -20 to +200 degree F.
Needle valves are used for precise regulations of liquids or gases in a piping system by moving the tip on the valve stem (the needle) into and out of the flow. Both the shape of the stem tip and the fine threads on the valve stem help the needle to be placed at precise points between fully open and fully closed. A needle valve's material type determines its usage—for example, metal valves are suitable for high pressure environments, while composite valves can be used in light weight applications The bonnet on needle valves can be integral (forged or milled as part of the valve body for strength), threaded (for durable pressure-tight seals where removal or replacement is not needed), or union (fits over the valve stem and held in place with a ring nut for repeated removal and replacement). Hand wheels, lever, and T-bar handles are made from various composites and materials that can be color coded for quick identification. These valves are used as either stand-alone valves or as flow control valves for gauges or instruments that could be damaged by flow and pressure fluctuations. Needle valves are suitable for use in fine adjustment and regulated flow applications in industries such as gas, chemical, hot water heating, and in scientific labs and textile manufacturing.
Parker Hannifin manufactures electromechanical, hydraulic, and pneumatic motion technologies and systems for liquid handling, filtration, sealing and shielding, climate control, process control, and aerospace applications. The company, founded in 1918, is headquartered in Cleveland, OH.