Description
When pressure at 1 rises above the spring bias pressure, the poppet is lifted and flow allowed from 1 to 2. The valve is closed (checked) from 2 to 1. When sufficient pilot pressure is present at port 3, the pilot piston acts to hold the poppet on its seat and flow is blocked from 1 to 2. Precision machining and hardening processes allow virtually leak-free performance in the checked condition.