Vb85 unloader valve 280 bar. Dynamic seals made up of O-ring and runner in Teflon. Optimised internal passages that guarantee reduced pressure loss. Anti-rotation device of the piston positioned inside the valve and obtained by an hexagonal sector of the piston itself. O-rings of the fittings positioned upstream to the thread : no risk of fittings ejected in case of over pressure. Double feed connection. Version with knob fitted with lock-nut for minimum working pressure adjustment.