Abstract: A ball valve for controlling the flow of a fluid is provided having primary and secondary annular sealing seats which are disposed in the body cavity for the purpose of providing a seal between the valve body and a first hemisphere of a ball. An annular leak detection channel is defined between the primary and secondary annular sealing seat for collecting fluid that leaks past the primary sealing seat. A purge is defined in the valve body extending from the channel to the exterior of the valve body, for establishing fluid through-flow and for draining fluid away from the secondary sealing seat that collects in the channel. A third annular sealing seat sealingly engages a second hemisphere of the ball.

Abstract: A fluid control valve, which allows selective change of the flow rate of fluid through the valve in the face of high temperatures and high pressures without undue wear to the integral downstream sealing seat, includes a body, having a passageway which consists of a first section and a second section, and a ball disposed in the second section of the passageway. The ball is rotatable around a central axis and has a first through hole of one diameter and a second through hole having a minimum diameter which is smaller than the first diameter. A sacrificial annular upstream seat is disposed upstream from the ball and has an internal diameter smaller than both the diameter of the first through hole and the diameter of the first section of the passageway through the body.

Abstract: A pressure relief valve is disclosed that includes a ball valve and an electrically powered valve operator for opening and closing the valve in response to electrical signals. A conduit connects a piezoelectric pressure gauge to upstream pressure. The gauge sends opening and closing electrical signals to the operator when the pressure in the conduit reaches preselected amounts.