GB5135.4-2025
Automatic sprinkler system—Part4: Dry pipe valves and accelerator
自动喷水灭火系统 第4部分：干式报警阀、加速器
GB 5135.4-2025 is an upcoming mandatory Chinese national standard for Automatic sprinkler system—Part4: Dry pipe valves and accelerator. It appears in the Environment compliance cluster with a product safety focus and has an implementation date of Nov 1, 2026.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard applies to the design, manufacturing, and inspection of dry pipe valves and accelerators used in automatic sprinkler systems. It is specifically tailored for fire protection engineering and manufacturers producing components for dry-pipe fire suppression setups. It does not apply to wet pipe systems, deluge valves, or preaction devices covered under other parts of the GB 5135 series.
Technical requirements
The standard mandates strict material criteria, requiring valve bodies and covers to have corrosion resistance not lower than ductile iron, and seats not lower than bronze. It defines specific structural and clearance parameters to prevent debris jamming, alongside detailed drainage requirements for intermediate chambers. Manufacturers must ensure proper anti-reseat latch mechanisms are in place for specific differential ratios to prevent automatic return to the set position during operation. For operational integrity, the standard specifies rated working pressures of 1.2 MPa or 1.6 MPa. It outlines rigorous functional requirements, including differential values for differential-type valves and actuation times for valves equipped with accelerators. Valves must successfully initiate and transmit alarm signals without failure under varying pressure conditions. Additionally, the standard sets forth requirements for non-metallic components, demanding they withstand extensive air and warm water aging without deformation. It also includes specific provisions for hydraulic friction loss, impact resistance, and fire resistance, ensuring the valve assembly maintains integrity under extreme environmental and mechanical stress.
Testing methods
The standard outlines a comprehensive suite of evaluations, including air and warm water aging tests for non-metallic parts, and extended immersion tests for valve seal components. These procedures ensure long-term durability and prevent seal adhesion under thermal stress. Hydrostatic strength tests are conducted at 4 times the rated working pressure, while leak and deformation tests are performed at 2 times the rated pressure. The standard also details a functional test to measure actuation points, differential ratios, and alarm port pressures. Specialized tests for anti-reseat mechanisms, impact resistance, and an 800°C fire resistance test are also mandated to verify structural survivability.
FAQs
What products are regulated under GB 5135.4-2025?
This standard regulates dry pipe valves and accelerators used in automatic sprinkler systems. It specifically covers components designed for dry systems where the network piping is charged with pressurized air or nitrogen rather than water.
Are there any updates from the previous version of GB 5135.4?
The 2025 version is a mandatory combined revision replacing both GB 5135.4-2003 and GB 5135.8-2003. It introduces new requirements for anti-reseat mechanisms, impact resistance, and structural clearances, while updating the rated working pressure ratings to 1.2 MPa or 1.6 MPa.
How does GB 5135.4-2025 differ from ISO standards?
While it shares similarities in safety principles with international standards like ISO or NFPA guidelines, GB 5135.4-2025 is tailored specifically for the Chinese market. It mandates distinct testing procedures, such as specific hydraulic friction limits at 4.5 m/s and localized fire resistance testing at 800°C for 15 minutes.
The summary above provides a high-level overview of GB 5135.4-2025. To ensure complete compliance for your products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 5135.4-2025 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Safety
- CCS
- C84
- ICS
- 13.220.10
- Competent department
- National Fire and Rescue Administration
- Technical committee
- National Technical Committee on Fire Protection of Standardization Administration of China
Relationships
Replaces:GB 5135.4-2003 (Current) , GB 5135.8-2003 (Current)