ISO 23555-2:2022 pdf – Gas pressure safety and control devices for use in gas transmission, distribution and installations for inlet pressures up to and including 10 MPa — Part 2: Gas pressure regulator.
1 Scope This document specifies safety, constructional, performance, testing and documentation requirements for gas pressure regulators for use in gas transmission and distribution installations (hereafter referred to as regulators). This document is applicable to regulators with operating pressures greater than 500 kPa and up to and including 10 MPa (100 bar) and nominal diameters up to DN 400 for use with fuel gases as natural gas, manufactured gas, biomethane or liquefied petroleum gas (LPG). This document is applicable to: — test methods which are intended for product type test, routine tests and product surveillance tests; — regulators which use the pipeline gas as a source of control energy unassisted by any external power source; — regulators integrating on the same body a second regulator, used as monitor, complying with the requirements in this document; — regulators integrating a safety shut off device (SSD) according to ISO 23555-3; — regulators incorporating a creep (venting) relief device and/or a vent limiter complying with the requirements in this document. This document does not apply to: — regulators upstream from/on/in domestic gas-consuming appliances which are installed downstream of domestic gas meters; — regulators designed to be incorporated into pressure control systems used in service lines (pipework from the main pipework in a gas infrastructure to the point of delivery of the gas) with declared volumetric flow rate ≤ 200 m 3 /h at normal conditions and declared inlet pressure ≤ 500 kPa (5 bar); — industrial process control valves, such as IEC 60534 (all parts); — regulators used in aggressive/sour gas environments (gas environments containing water and H2S are considered sour) or severely corrosive conditions; — regulators in service conditions with renewables (e.g. H2NG with hydrogen more than 10 %) and/ or waste gases (e.g. biogas etc.), if additional information is not provided (e. g. contaminant, liquid, etc.).
2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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. ISO 23555-1:2022, Gas pressure safety and control devices for use in gas transmission, distribution and installations for inlet pressures up to and including 10 MPa — Part 1: General requirements 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 IEC 60534-4, Industrial-process control valves — Part 4: Inspection and routine testing 3? Terms? and? definitions? and? symbols 3.1? Terms? and? definitions For the purposes of this document, the terms and definitions given in ISO 23555-1 and the following apply. ISO and IEC maintain terminology databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https:// www .org/ obp — IEC Electropedia: available at https:// www .electropedia .org/ 3.1.1 General terms 126.96.36.199 gas pressure regulator device whose function is to maintain the value of the controlled variable (188.8.131.52) within its tolerance field irrespective of disturbance variables 184.108.40.206 direct acting gas pressure regulator regulator in which the net force required to move the control member is supplied directly by the controlled variable Note 1 to entry: See example in Figure 1.
220.127.116.11 fail close regulator regulator whose control member automatically tends to close or close when failures occur Note 1 to entry: This definition is based on typical control failure modes. 18.104.22.168 fail open regulator regulator whose control member automatically tends to open or open when failures occur Note 1 to entry: This definition is based on typical control failure modes. 22.214.171.124 regulator size nominal size DN of the inlet connection Note 1 to entry: The preferred DN values are specified in ISO 6708. 126.96.36.199 series of regulators regulators with the same design concept but differing only in size 3.1.2? Terms? related? to? flow 188.8.131.52 flow? coefficient? in? critical? conditions Cg characteristic value for the flow capacity of regulator in critical conditions Note 1 to entry: Flow coefficient Cg is a non-SI regulator coefficient. Note 2 to entry: Numerically, Cg is represented as the number of normal cubic feet per hour of air flowing through a regulator in critical conditions with inlet absolute pressure 1 psia and with a reference inlet temperature t ur = 15 °C 1) . The numerical value in SI units is equal to the number of m 3 /h of air flowing through a regulator in critical conditions with inlet absolute pressure 243 kPa (2,43 bar) and inlet temperature of 15 °C. Note 3 to entry: IEC 60534-2-1:2011, Clause 7 and Appendix B deals with this flow coefficient.