Rettberg® relief / check valve, core NS 19/26

with side glass stopcock 3 mm overpressure / check valve, core NS 19/26, with side glass stopcock 3 mm bore, borosilicate glass 3.3. A spring-loaded spherical ground joint serves as overpressure valve, whereby a higher viscosity sealing liquid ensures tightness. The spring pressure is adjustable. Maximum overpressure 0.1 bar. As a check valve, the device can be used under vacuum, and a recessed riser tube prevents contamination by sealing liquid. For particularly aggressive media, the spring can also be covered with inert liquid.