Abstract: Fault diagnostics utilize an embedded tracking digital twin of a valve assembly physical part in a microprocessor system of the valve positioner. The digital twin has simulation model parameters including a fault-related simulation model parameter. The digital twin receives a control signal representing a real control of the at least part of the valve assembly, and generates simulated measurements relating to the simulated control result. The digital twin compare the simulated measurements with real measurements that relate to the real control result, to track an error between the results of simulated operation and the real operation of the valve assembly to adjust the fault-related simulation model parameter in a sense that the error is decreased. The fault-related simulation model parameter relates to a specific physical fault in the physical part of the valve assembly, and it is detectable and identifiable based on the simulation model parameter adjusted value.

Abstract: A valve sealing arrangement, including a valve body, and a closing member including a closing member contact surface, and a seat, having a center axis, and provided with a sealing portion with a first sealing surface for making contact with the closing member and a back sealing portion with a second sealing surface for making contact with a surface of the valve body. The seat also includes a bellows between the first sealing surface and the second sealing surface wherein the bellows including bellow members wherein adjacent bellow walls form either inwardly open fold or outwardly open fold and wherein one or more of the bellow members extends in a direction that is oblique to the center axis of the seat.

Abstract: A valve sealing arrangement, including a valve body, and a closing member including a closing member contact surface, and a seat, having a center axis, and provided with a sealing portion with a first sealing surface for making contact with the closing member and a back sealing portion with a second sealing surface for making contact with a surface of the valve body. The seat also includes a bellows between the first sealing surface and the second sealing surface wherein the bellows including bellow members wherein adjacent bellow walls form either inwardly open fold or outwardly open fold and wherein one or more of the bellow members extends in a direction that is oblique to the center axis of the seat.

Abstract: The invention relates to a valve having an inlet and an outlet, and a closure member. The closure member comprises an inlet area with a plurality of inlet openings and an outlet area. Main flow channels extend from initial openings in the inlet area through the closure member to openings in the outlet area, said initial openings are located in an initial flow inlet area of the inlet area which is first subjected to fluid from the inlet of the valve when the closure member is rotated from a fully closed position towards an initially open position.

Abstract: The invention relates to a valve having an inlet and an outlet, and a closure member. The closure member comprises an inlet area with a plurality of inlet openings and an outlet area. Main flow channels extend from initial openings in the inlet area through the closure member to openings in the outlet area, said initial openings are located in an initial flow inlet area of the inlet area which is first subjected to fluid from the inlet of the valve when the closure member is rotated from a fully closed position towards an initially open position.