IEC 60534-2-4:2009 pdf downlaod – Industrial-process control valves – Part 2-4: Flow capacity – Inherent flow characteristics and rangeability
1 Scope
This part of IEC 60534 applies to all types of industrial-process control valves. It defines how to state typical control valve inherent flow characteristics and inherent rangeabilities. It also defines how to establish criteria for adherence to manufacturer-stated flow characteristics.
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 or the referenced document (including any amendments) applies.
IEC 60534-1 :2005, Industrial-process control valves – Part 1: Control valve terminology and general considerations
IEC 60534-2-3, Industrial-process control valves – Part 2-3: Flow capacity – Test procedures
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60534-1 and the following apply.
3.1
flow coefficient
(see IEC 60534-1 , 4.6)
3.2
rated flow coefficient
(see IEC 60534-1 , 4.6.3)
3.3
relative flow coefficient ( Φ )
Φ 0 is the relative flow coefficient at 0 % relative travel
[IEC 60534-1 , 4.9 modified]
3.4
travel
(see IEC 60534-1 , 4.5.2)
3.5
rated travel
(see IEC 60534-1 , 4.5.3)
3.6
relative travel (h)
(see IEC 60534-1 , 4.5.4)
