The DB5500 double block and bleed plug valve, dual expanding plug valve and non-friction double tight shut-off valve in both the up and down stream. No maintenance and the valve reduces space. There are two seated surfaces (slips). When the valve is in the closed position each individual seal is fully isolating, now allowing any leakage from downstream, upstream, nor from the body cavity. A thermal relief vents/bleeds the body cavity when overpressure occurs so the downstream pipeline is fully isolated from upstream pressure without there being pressure balancing.
DB5500 Series Brochure