GB5135.3-2025
Automatic sprinkler system—Part 3:Water spray nozzle
自动喷水灭火系统 第3部分:水雾喷头
GB 5135.3-2025 is an upcoming mandatory Chinese national standard for Automatic sprinkler system—Part 3:Water spray nozzle. 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 water spray nozzles used in automatic sprinkler systems. It covers various classifications, including open and closed water spray nozzles, utilizing either centrifugal or impact atomization mechanisms. Manufacturers of fire protection components must ensure their water spray nozzles comply with these updated national requirements.
Technical requirements
The standard specifies comprehensive physical and performance requirements for water spray nozzles. Key areas include flow coefficient tolerances, spray angle accuracy, and water distribution performance, ensuring the nozzle effectively atomizes water into droplets below a specific diameter threshold. The design and manufacturing process must guarantee that nozzles cannot be arbitrarily adjusted, disassembled, or reassembled by end-users. It mandates rigorous environmental and durability testing criteria. The nozzles must withstand extreme conditions, demonstrating resistance to stress corrosion (including ammonia and magnesium chloride environments), sulfur dioxide/carbon dioxide corrosion, and salt spray. Additionally, the standard outlines requirements for low and high-temperature endurance, vibration resistance, and mechanical impact resilience. For closed-type water spray nozzles, the standard incorporates additional criteria referenced from GB 5135.1, covering thermal sensitivity, operational loads, and dynamic thermal response. Compliance with these multifaceted requirements is mandatory to ensure reliable fire suppression performance.
Testing methods
The standard outlines specific testing procedures to verify compliance, including flow coefficient measurement at various pressures, spray angle photography, and water distribution testing using a grid of catchment devices. It also details environmental corrosion tests (ammonia, magnesium chloride, salt spray) and physical endurance tests for vibration, mechanical impact, and thermal extremes. Each test is designed to simulate harsh operational conditions and verify the long-term reliability of the nozzle.
FAQs
What products are regulated under GB 5135.3-2025?
The standard regulates water spray nozzles used in automatic sprinkler systems, encompassing both open and closed types, as well as centrifugal and impact atomization models.
Are there any updates from the previous version of GB 5135.3?
The 2025 version introduces overall requirements, updated model numbering, and new test methods for magnesium chloride stress corrosion, sulfur dioxide/carbon dioxide corrosion, and dust cap performance. Manufacturers previously certified under the 2003 version must update their compliance to meet these new mandatory parameters.
How does GB 5135.3-2025 differ from ISO standards?
While it shares similarities with international fire protection standards, GB 5135.3-2025 is tailored specifically for the Chinese market's regulatory framework. It references GB 5135.1 for certain closed nozzle specifications and mandates specific testing procedures and tolerance limits unique to the Chinese standard system.
The summary above provides a high-level overview of GB 5135.3-2025. 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 5135.3-2025 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Product
- 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 5135.3-2003 (Current)