Compact manifold ball valve

摘要

A compact manifold ball valve having a valve body defining a valve chamber and having first and second ends and a first flow passage intersecting the valve chamber a cylindrical sealing surface defining a bonnet and valve stem passage also intersecting the valve chamber. A seat and ball retainer is threaded into the second end of the valve body and provides for support and positioning of a pair of trunnion support elements and a pair of seat assemblies. A valve ball having opposed trunnions is rotatable between open and closed positions within the valve chamber and is supported by the trunnion supports. A valve stem and bonnet assembly is secured and sealed to said valve body and is actuated to rotate the valve ball for opening and closing thereof. The valve seats are capable of metal-to-metal sealing with the valve ball in the event of heat destruction of said face seals to provide the valve with a fire-safe character. The seats incorporate high temperature graphite filament seals for fire-safe sealing between the valve seats and valve body in the event of heat destruction of said back seals. Other internal metal surfaces are arranged for metal-to-metal fire-safe sealing in the event the primary seals are destroyed by heat.