Parker-Hannifin's General Valve Operation is introducing Series 99, a new line of miniature solenoid valves for vacuum applications. "There are no elastomers in the flow paths," says Aman Sharafi, senior applications engineer at General Valve. "It's unique that way."
The lack of elastomers in this type of vacuum valve is especially important in gas chromatograph and other analytical processes where gases are used, according to Sharafi. "Gases permeate rubber and elastomers, so the seals become compromised."
Sharafi explains that Series 99 valves have two points of sealing. "The first is an external seal called Gen-Lock," he says. The Gen-Lock seal is a gasket made from a choice of copper, nickel, or one of several plastics.
"The second seal is an internal, dynamic seal and is usually made from Teflonฎ or Vitonฎ materials," says Sharafi. He says the valves achieve leak rates of better than 1 ื 10-9 ATM-cc/sec Helium.
The valves have an opening response time of 5 msec and are available with orifice sizes from 50 microns to 2.9 mm. Their stainless steel construction withstands temperatures from -40 to 200C. Porting options for Series 99 valves include threaded ports, vacuum fittings, and compression fittings. The maximum operating pressure is 1,250 psi. The valves require no pressure for operation.
All valves are tested for leaks with mass spectrometers. Series 99 valves work with both gases and liquids. The 1.6-inch high by 1.91-inch wide by 1-inch long valve has a solenoid cable with a diameter that measures 0.63 inch. For more information about valves from General Valve: Enter 534