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FTI's metal seal angle valves are intended for use in UHV or cryogenic applications where temperature extremes preclude the use of our elastomer seal valves. Approved for use in beamline facilities, these valves have a temperature operating range from 400°C to -250°C. Heater Jackets and controllers are available on request.
The pulled-port method is used for the fabrication of the stainless steel bodies resulting in higher conductance and better cleanliness.
The life of the copper poppet seal is dependent upon the temperature at which the valve is used. Maximum temperature bakeouts may require poppet seal replacement after 50 cycles, while hundreds of cycles are possible with moderate bakeouts. As many as 10,000 cycles have been obtained from the same seal during testing.
A dial indicator at the top of the valve indicates the proper torque for closure and also when the seal should be replaced. The copper poppet seal is easily replaced by opening the valve with a slotted screw driver. The seal is removed through the side port and a new one replaced in a like manner. After seal replacement the valve must be torqued to a higher value than during normal operation to make it seat. Do not exceed the maximum torque specifications. (See torque specifications table). After closing the valve to its normal torque value loosen the set screw below the closure nut, rotate the indicator to the furthest counter-clockwise line on top of the valve and retighten the set screw. The valve may be closed to this mark indefinitely. Periodic checks with a torque wrench will indicate seat wear and the proper mark to use for alignment. When the indicator has reached the last mark we recommend seal replacement.
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