IEC 60534-1-2005 pdf – Industrial-process control valves – Part 1: Control valve terminology and general considerations

IEC 60534-1-2005 pdf – Industrial-process control valves – Part 1: Control valve terminology and general considerations
1 Scope This part of IEC 60534 applies to all types of industrial-process control valves (hereinafter referred to as control valves). This part establishes a partial basic terminology list and provides guidance on the use of all other parts of IEC 60534. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60534 (all parts), Industrial-process control valves 3 Component terminology 3.1 control valve power-operated device which changes the fluid flow rate in a process control system. It consists of a valve connected to an actuator that is capable of changing the position of a closure member in the valve in response to a signal from the controlling system 3.1.1 control valve with a linear motion closure member 3.1.1.1 diaphragm valve valve in which a flexible closure member isolates the line fluid from the actuating mechanism and provides a seal to the atmosphere 3.1.1.2 gate valve valve whose closure member is a flat gate that moves in a direction parallel to the plane of the seat 3.1.1.3 globe (angle) valve valve in which the closure member moves in a direction perpendicular to the plane of the seat(s)
3.1.2 control valve with a rotary motion closure member 3.1.2.1 ball valve valve with a closure member that is a sphere with an internal passage. The centre of the spherical surface is coincident with the axis of the shaft. 3.1.2.2 segmented ball valve valve with a closure member that is a segment of a sphere. The centre of the spherical surface is coincident with the axis of the shaft 3.1.2.3 butterfly valve valve with a circular body and a rotary motion disk closure member, pivotally supported by its shaft. The shaft and/or closure member may be centred or offset 3.1.2.4 plug valve valve with a closure member that is cylindrical or conical, with an internal passage 3.1.2.5 eccentric plug valve valve with an eccentric closure member that may be in the shape of a spherical or conical segment 3.2 valve assembly forming a pressure retaining envelope containing a closure member for changing the flow rate of the process fluid 3.2.1 valve body part of the valve which is the main pressure retaining boundary. It provides the fluid-flow passageways and the pipe-connecting ends 3.2.2 bonnet portion of the valve which closes an opening in the body and through which passes the stem connecting the closure member to the actuator 3.2.3 end connection valve body configuration provided to make a pressure tight joint to the pipe carrying the fluid to be controlled 3.2.3.1 flanged ends end connections incorporating flanges which allow pressure seals by mating with corres- ponding flanges on the piping
3.2.3.3 threaded ends end connections incorporating threads, either male or female 3.2.3.4 welded ends end connections where valve body ends have been prepared for welding to the line pipe or other fittings. Such connections may be of the butt-weld or socket-weld types 3.2.4 valve trim functional components of the valve, excluding the body, bonnet and blind head (if present), which are in contact with the fluid 3.2.4.1 valve seats corresponding sealing surfaces within a control valve which make full contact when the control valve is in the closed position 3.2.4.2 seat ring part assembled in the valve body to provide a removable valve seat 3.2.4.3 closure member movable part of the valve which is positioned in the flow path to restrict the flow through the valve. A closure member may be a plug, ball, disk, vane, gate, diaphragm, etc. 3.2.4.4 valve stem (or shaft) component extending through the bonnet which connects the actuator to, and positions, the closure member. For rotary valves, the word shaft should be used in place of stem 3.3 actuator device or mechanism which transforms a signal into a corresponding movement controlling the position of the internal regulating mechanism (closure member) of the control valve. The signal or energizing force may be pneumatic, electric, hydraulic, or any combination thereof 3.3.1 actuator power unit that part of the actuator which coverts fluid, electrical, thermal or mechanical energy into actuator stem motion to develop thrust or torque 3.3.2 yoke structure which rigidly connects the actuator power unit to the valve. It can be an integral part of the bonnet or actuator