The QSB quarter swing valves are compact, quick acting, high conductance isolation valves. The QSB valves have a polished, stainless steel, ISO flanged body with fluoroelastomer ‘O’ ring sealed valve plate and shaft. The valve plate ‘O’ ring groove is vented to help maintain a stable high vacuum. The valve shaft ‘O’ rings and bearings are lubricated with Fomblin® grease to prevent gas bursts from behind the shaft seals.
 
This valve is supplied with a trapped ‘O’ ring.