What is ISO 23555‑2 - Documentation requirements for gas pressure regulators about?
ISO 23555 is a series on gas pressure safety and control devices for use in gas transmission, distribution, and installations for inlet pressures up to and including 10 MPa. A gas pressure safety and control device is a valve that controls the pressure of a fluid or gas to the desired value, using negative feedback from the controlled pressure. ISO 23555‑2 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).
ISO 23555‑2 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 such as natural gas, manufactured gas, biomethane or liquefied petroleum gas (LPG). ISO 23555‑2 is applicable to:
- Test methods that are intended for a product type tests, 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 integrate on the same body a second regulator, used as a monitor, complying with the requirements in ISO 23555‑2
- 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
Note: ISO 23555‑2 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 gas infrastructure to the point of delivery of the gas) with declared volumetric flow rate ≤ 200 m3/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.)
Who is ISO 23555‑2 - Documentation requirements for gas pressure regulators for?
ISO 23555‑2 on the documentation requirements for gas pressure regulators is useful for:
- Gas equipment manufacturers
- Gas regulator distributor
- Design engineers
- Quality control personnel
Why should you use ISO 23555‑2 - Documentation requirements for gas pressure regulators?
Regulators are used for gases and liquids and can be an integral device with a pressure setting, a restrictor and a sensor all in one body, or consist of a separate pressure sensor, controller, and flow valve. The gas pressure regulator is a device whose function is to maintain the value of the controlled variable within its tolerance field irrespective of disturbance variables. ISO 23555‑2 is designed to be used in combination with ISO 23555-1. ISO 23555‑2 together with ISO 23555-1 establishes the complete standard as it applies to the specific control covered by the ISO 23555 series. Where needed, this document adopts ISO 23555-1 by stating in the clause which includes “with the following modification”, “with the following addition”, “is replaced by the following”, or “is not applicable”.
In order to identify specific requirements that are particular to ISO 23555‑2 but not already covered by ISO 23555-1, ISO 23555‑2 can contain clauses or subclauses that are additional to the structure of ISO 23555-1. These subclauses are indicated by the introductory sentence: “Subclause specific to ISO 23555‑2.” Regulators do not have any continuous discharge of gas into the atmosphere. However, temporary discharges from auxiliary devices can occur. Regulators are designed so that the external tightness and internal sealing meet the requirements of ISO 23555‑2. If in the event of failure of the regulator (e.g., failure of a diaphragm) leakage to the atmosphere is possible, the breather is provided with a threaded connection of at least DN 10 to enable an exhaust line to be connected. This connection may be used for a specific device (e.g., a dumping device). For proper operation of the regulator, any exhaust line is designed in such a way as to prevent the ingress of foreign materials. Using ISO 23555‑2 you can specify safety, construction, performance, testing and documentation requirements for gas pressure regulators.
