These valves are equipped with ball checks that prevent uncontrolled release of liquid in case of tubular glass breaking. They feature 1/2" male NPT vessel connections for Series Q170 and 3/4" male NPT vessel connections for Series Q175. They are for use with highly durable Pyrex glass tubes of 5/8" diameter for Series Q170 and 3/4" diameter for Series Q175. The actual service pressure rating depends on the length and wall thickness of the glass tubes. Guard rods and a round Plexiglas cover are available to protect the glass tube. These items also feature vent/drain plugs for emptying the liquid in the tube for maintenance or inspection. The vent/drain threaded openings can be used to attach a stopcock for convenience.
