Abstract: A method for determining the performance of a control valve in a closed control loop by using a simulation model. A simulation model of a process control loop is provided, consisting of a unit process (2) including the flow equations of the valve, a process controller (4) and a process transmitter (3), to simulate a process with disturbances (6, 6'). The simulation model is connected to a real control valve (1), including a valve, an actuator and a positioner. The valve response is measured. The process variability during the process is determined.

Abstract: A valve and method for adjusting the flow of a valve and for forming a turbulence in the flow. The flow is led tangentially from the inlet passage (2) into the space inside the valve body (1) in such a way that a turbulent flow is formed inside the valve body, outside the closure member. The flow volume is adjusted before the flow is brought into turbulence.

Abstract: A method and a device for reducing the noise caused by throttling a gas flow in a flow channel (1), where after the throttling part (2) there is a wider part (3). The wider part (3) following the throttling part (2) of the flow channel (1) has at least one deviation of the cross-section (D) formed by a wall protrusion (5) in a short part (1) of the channel. The cross-section of the channel wall protrusion (5) taken length-wise of the channel tapers towards the central part of the channel. In a trans- or supersonic flow the protrusion causes a straight shock wave, a so-called Mach disk, in the flow, and this disk is made to occur and to remain within a wide pressure drop ratio range.

Abstract: A valve comprised of a valve body (1) incorporating a flow bore (2), of a check element (3) rotatably or pivotally adapted to said flow bore, said check element having the shape of rotational body or part of it, incorporating a flow port (4) and being supported by seat seals (5, 6), and of a driving stem (7). The stem is connected to the check element by means of a driver element (8) which is adapted to movably fit in a slot machined to the outside surface of the check element, said slot being aligned orthogonal to the longitudinal axis of the flow port of the check element. The driver element (8) is detachably joined to the stem (7). The end of the stem is adapted to a toothed, keyed or splined hole (12, 13) of the driver element (8) so as to render the joint a torque-transmitting capability.

Abstract: A control valve, which consists of a body (1) provided with flow-through channels (2, 3) and of a closing member (5) arranged rotatably in the body in an expansion (4) of the channel, the rotation shaft of which is eccentric in relation to the sealing surfaces of the closing member and the seal of the body. In an open position of the valve a circular flow is formed around the closing member between a wall of the body and the closing member (5), the main flow passage of which circular flow is located in a channel between the inner surface of the body and the upstream edge (16) of the closing member. The closing member (5) has an extension (17) in its upstream edge (16) in the open position, which extension in an initial phase of the opening reduces the cross-sectional area of the main flow passage.