Abstract: A method for adjustment and/or indication of a liquid or gaseous pressure, and advice for utilization of the method, including the use of a piston member (7, 7'), movably arranged in a surrounding housing (1), said member having two towards each other acting piston areas with different area, said piston areas being made subject to a pressure from the liquid or gaseous medium, a mechanical load also being supplied to the smaller piston area, whereby the piston surfaces only perform a common movement when the media pressure exceeds a predetermined limiting value, which limiting value comprises of resulting force for the force developed by the smaller piston area under influence of supplied media pressure and added mechanical force, said movement, when predetermined limiting value is exceeded, being arranged to influence a flow restricting valve member and/or indicate the pressure of supplied media.

Abstract: A method for installing an adjustable flow restricting valve member in a tubular pipe, and a valve device for utilization of the method, including the steps of cutting a slot extending in the longitudinal direction of the tubular pipe, inserting a mainly plane valve member through said slot, said valve member being arranged with a stem extending through the slot and facilitating a rotary movement of the valve member from a position corresponding with the length axis of the tubular pipe to a position in contact with the internal wall surface of the tubular pipe, said stem also extending through a member arranged to prevent communication between a medium within the pipe and the outside atmosphere.