Key High's BA/BL series brass valves are bellows sealed valves with a machined valve body using ASTM B 16 material. This method eliminates porosity issues and virtual leaks. The rugged design and simple construction assure a high cycle life and ease of maintenance. The BA/BL Series valves feature short flow paths, which make the BA/BL series valves perfect foreline valves for inert gas applications.
BA/BL series valves are perfect foreline valves for inert gas applications. BA/BL Series valves are offered in right angle and inline versions and with three standard interfaces: NW flanges, Female NPT ports (1/8" to 1 1/2") and tube socket weld ports (3/8”" to 2 1/8" tube od). Socket weld valve bodies can be hard-soldered or soft-soldered into the foreline. When soldering the valve into the foreline, always remove the complete bellows assembly. The heat from soldering will damage the seals and actuator. After soldering, the valve body should be completely glass-beaded and polished to remove flux, oxidization, etc. During soldering, great care should be taken to protect the valve bonnet and seat.
The BA/BL Series valves are offered in two different poppet styles. The disk seal version features a Viton® washer on the poppet. Due to the larger sealing area, the disk design benefits from higher dirt-carrying ability. Also, the disk seal can be flipped over to double the seal's life. O-ring seal valves feature a Viton® O-ring incorporated into the poppet. The benefit of the O-ring seal is a minimum of elastomer located within the vacuum envelope.
Manual valves have an acme threaded stem, allowing quick valve opening and closing.
Pneumatic valves have a double-acting air cylinder and a 120/60 solenoid as the standard offering. Other voltages are available upon request. BA/BL series pneumatic valves require a compressed air supply of 60 to 100 psig. Key High’s pneumatic BA/BL series valves will close in the event of a power failure. Key High offers spring-loaded, normally closed air cylinders (fail safe/close). Reed switches are available as an option for double-acting air cylinders only. When ordering Reed switches, the voltage requirement must be specified at the time of order as the Reed switches are voltage specific.
BA/BL series valves are designed to operate in high vacuum systems at pressures as low as 5 x 10-8 torr. All BA/BL series vales are leak tested on a helium mass spectrometer before shipment 2 x 10-9 std cc/sec He.
