A gauge valve valve is often a single shutoff needle valve, that isolates the gauge from the method. What is variance in 2 way manifold valve & gauge valve? I dunno why my standard manager explained that use gauge valve instead of 2 way manifold valve in stress gauge. plz http://double-block-and-bleed-va41616.jiliblog.com/24078664/not-known-details-about-gauge-valve