Ensure your semi is Ready for the Road Ahead with safe air pressure levels, with the Sealco 3/8" NPT 70 psi Emergency Control Pressure Protection Valve. To prevent over pressurization, this replacement component monitors the internal pressure of the air brake system, releasing air pressure once it exceeds a certain level. Fashioned with innovative technology to reduce the chance of leaks and mechanical failures. FleetPride is your First Click in Heavy Duty .