Specifically intended for high vacuum service. Valves are supplied in either 316L stainless steel or brass, in 3.2mm (1/8") to 152.4mm (6") tube O.D., pipe thread or ISO KF and ISO LF end connections. Teflon seats and Viton seals are standard, however, other combinations are available on request.
Ball valves offer straight through flow providing maximum conductance, interchangeable end connections, unobstructed ports and low initial installation and maintenance costs.
Gas entrapment has been eliminated by drilling an evacuation hole in the shut-off side of the ball exposing the body cavity to either upstream or downstream pressure depending on installation. A further advantage is the rigid stem assembly which prevents lateral movement during actuation that has affected users of other valves in the past.
Stem seals are easily replaced and only three bolts need to be removed to service the seats and body seals.
Provisions are made to evacuate the area between the seat and the body up to the body seal.
Each valve is (mass spectrometer) helium leak checked and certified. Guaranteed leakage rate is less than 1 x 10(-9) std. cc/sec.
These ball valves available through Laser Support Services are machined from solid round 316L grade stainless steel bar. Experience has shown that for vacuum applications, cast ball valves are subject to voids, microscopic leak paths, porosity and inclusion in the material. This leads to virtual leaks, out-gassing, permeation and longer pump down times. In addition to this, the machined ball valves achieve faster pump down times and lower absolute vacuum pressure.
Please contact us for more information or to discuss your requirements.