BS EN 736-1-2018 pdf free download.Valves – Terminology Part 1: Definition of types of valves
This European Standard specifies the denominations of valves to provide a uniform and systematic terminology for all types of valves.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 valve
piping component which influences the fluid flow by opening, closing or partially obstructing the passage of the fluid flow or by diverting or mixing the fluid flow
4 Types of valves related to design
4.1 Basic types
4.1.1 General
By reasons of classification of terms, Clause 4 provides definitions related to basic design characteristics.
Table 1 shows the basic types of valves.
They are distinguished by:
a) the type of motion of the obturator;
b) the direction of flow towards the seating surface.
4.1.2 Gate valve
A gate valve is a valve in which the obturator movement is linear and, towards the seating surface, at right angle to the direction of flow.
4.1.3 Globe valve
A globe valve is a valve in which the obturator movement is linear and, towards the seating surface, in parallel to the direction of flow.
NOTE This definition also applies to lift check valves and axial check valves.
4.1.4 Plug and ball valve
A plug and ball valve is a valve in which the obturator rotates about an axis at right angle to the direction of flow and, in the open position, the flow passes through the obturator.
4.1.5 Butterfly valve and eccentric plug valve
A butterfly and eccentric plug valve is a valve in which the obturator rotates about an axis at right angle to the direction of flow and, in the open position, the flow passes around the obturator.
NOTE This definition also applies to swing check valves.
4.1.6 Diaphragm valve
A diaphragm valve is a valve in which the fluid flow passage through the valve is changed by deformation of a flexible obturator.
NOTE This definition also applies to diaphragm check valves.
5 Types of valves related to function
5.1 General
Clause 5 defines terms related to the functional characteristics of valves.
5.2 Isolating valve
An isolating valve is a valve intended for use only in the closed or fully open position.
5.3 Regulating valve
A regulating valve is a valve intended for use in any position between closed and fully open.
5.4 Control valve
A control valve is a power operated device which changes the fluid flow rate in process control system.
It consists of a valve connected to an actuator with or without positioner that is capable of changing the position of an obturator in the valve in response to a signal from the control system.
5.5 Safety valve
A safety valve is a valve which automatically, without the assistance of any energy other than that of the fluid concerned, discharges a certified quantity of the fluid so as to prevent a predetermined safe pressure being exceeded, and which is designed to reclose and prevent further flow fluid after normal pressure conditions of service have been restored.
5.6 Bursting disc safety device
A bursting disc safety device is a non‑reclosing pressure relief device actuated by differential pressure and designed to function by the bursting of the bursting disc(s). It is the complete assembly of installed components including, where appropriate, the bursting disc holder.
5.7 Check valve
A check valve is a valve which automatically opens by fluid flow in a defined direction and which automatically closes to prevent fluid flow in the reverse direction.
NOTE Definitions of types of check valves are given in 4.1.3, 4.1.5 and 4.1.6.
5.8 Diverting valve
A diverting valve is a valve intended to influence the proportion of two or more output flows from a common input flow, by changing the position of the obturator.
5.9 Mixing valve
A mixing valve is a valve intended to influence the proportion of the two or more input flows to produce a common output flow by changing the position of the obturator.
5.10 Automatic steam trap
An automatic steam trap is a self‑contained valve which automatically drains the condensate from a steam containing enclosure whilst remaining tight to live steam or, if necessary, allowing steam to flow at a pre‑determined rate.
5.11 Bleed valve
A bleed valve is a valve equipped, upstream and/or downstream of the obturator, with branch to purge part of the upstream or downstream piping.BS EN 736-1 pdf download.