GB27790-2020

City gas pressure regulator

城镇燃气调压器

GB 27790-2020 es una norma nacional china obligatoria vigente: City gas pressure regulator. Sector: Construcción. Enfoque: Seguridad de productos. Entrada en vigor: 1 dic 2021.

La aplicabilidad depende del alcance del producto, la vía de certificación, los avisos de la autoridad competente y las reglas de transición. Solicite una traducción o verifique la fuente antes de usar esta ficha en una decisión de cumplimiento.

Resumen de cumplimiento

Este resumen está disponible por ahora solo en inglés.

Alcance y aplicabilidad

GB 27790-2020 applies to city gas pressure regulators with a maximum inlet pressure of 10.0 MPa, operating temperatures ranging from -20°C to 60°C, and nominal sizes up to DN400. This standard is mandatory for manufacturers producing regulators used in urban gas distribution networks. It does not apply to bottled LPG regulators or dimethyl ether regulators. The standard covers both direct-acting and indirect-acting regulator types, including those with integrated shut-off, monitor, and release units.

Requisitos técnicos

The standard specifies comprehensive requirements across several key areas: structural design and materials, including design pressure criteria for metallic pressure-bearing parts, metal diaphragms, and membranes, as well as material selection rules for cast steel, ductile iron, aluminum alloys, and rubber components. Manufacturers must ensure all pressure-bearing components meet specific elongation and impact toughness requirements, particularly for low-temperature applications below -10°C. Performance requirements cover static characteristics such as accuracy class (AC), lock-up pressure class (SG), and lock-up pressure zone class (SZ), each with defined tolerance bands. The standard also specifies flow coefficient ($C_g$) requirements, external and internal sealing limits, and durability requirements mandating 30,000 open-close cycles without performance degradation. Safety and functional requirements include fail-safe states (fail-open or fail-close behavior upon membrane failure or loss of driving pressure), performance criteria for integrated shut-off units, integrated monitor units, and integrated release devices. Meter pressure regulators (表前调压器) have additional requirements for anti-tamper measures, torsion resistance, and bending resistance. The standard also introduces new requirements for non-destructive testing of steel pressure-bearing parts (referencing NB/T 47013), including radiographic, ultrasonic, magnetic particle, and penetrant testing at specified sampling ratios based on design pressure and nominal size.

Métodos de ensayo

Testing methods include: Hydraulic strength testing of pressure-bearing parts at 1.5× design pressure; external sealing tests using leak detection fluid, water immersion, or pressure-drop methods; static characteristic testing across multiple inlet/outlet pressure combinations to determine accuracy class, lock-up pressure, and flow ranges; flow coefficient ($C_g$) determination under critical and sub-critical flow conditions; extreme temperature adaptability tests at -20°C and 60°C; durability testing with 30,000 cycles; fail-state verification through analysis or testing; and specialized tests for integrated safety units referencing CJ/T 335-2010 and CJ/T 180-2014.

Preguntas frecuentes

What products are regulated under GB 27790-2020?

GB 27790-2020 regulates city gas pressure regulators with inlet pressure ≤10.0 MPa, operating temperatures between -20°C and 60°C, and nominal sizes ≤DN400. It excludes bottled LPG regulators and dimethyl ether regulators.

What are the key updates from GB 27790-2011 to GB 27790-2020?

Key updates include: addition of meter pressure regulator special requirements, new non-destructive testing requirements for steel pressure-bearing parts, new requirements for fail states, integrated shut-off, monitor, and release units, modified membrane testing methods, and updated rubber material performance specifications in Appendix A.

Does GB 27790-2020 reference international standards?

The standard primarily references Chinese national standards (GB/T series) and industry standards (CJ/T, NB/T, JB/T series). While it does not directly adopt ISO standards, many of its technical concepts—such as flow coefficient $C_g$ and accuracy classes—are aligned with international gas regulator engineering practices.

The summary above provides a high-level overview of GB 27790-2020. To ensure complete compliance for your gas pressure regulators entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 27790-2020 today to access all detailed parameters, material tables, testing procedures, and inspection rules.

Indicaciones de aplicabilidad

Tipo: Seguridad
CCS: P47
ICS: 91.140
Organismo competente: Ministry of Housing and Urban-Rural Development
Comité técnico: Ministry of Housing and Urban-Rural Development

Relaciones

Sustituye a:GB 27790-2011