Burns Pressure Systems has introduced its Model 3" MBF fully internal relief valve, designed for transports and other storage vessels. Its flush-mount design prevents shearing in a rollover. The factory-set-and-sealed pressure setting is inside the tank to prevent tampering. Rated from 15 to 500 psi, the valve is rebuildable, and several materials are available. For more information, contact BPS Inc, 304 N Walnut, Broken Arrow OK 74012.