d. A bleed Valve need to be installed amongst the outlet isolation Valve and force-relief machine to permit the technique to become properly depressurized prior to undertaking routine maintenance. As outlined by API 6D “Specification for Pipeline Valves” standards, a double block-and-bleed valve is actually a “one valve with http://cruzyfsmn.tinyblogging.com/double-block-and-bleed-valve-An-Overview-27722918