GB3446-2026
Siamese connection
消防水泵接合器
GB 3446-2026 is an upcoming mandatory Chinese national standard for Siamese connection. It appears in the Environment compliance cluster with a product safety focus and has an implementation date of Feb 1, 2027.
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
GB 3446-2026 applies to various fire pump siamese connections (also known as fire department connections) installed in fire protection piping systems. It covers above-ground, underground, wall-mounted, and multi-purpose installation types. This standard is mandatory for manufacturers producing fire protection equipment for the Chinese market. It specifically targets systems with nominal outlet sizes of DN100 and DN150, and rated working pressures of 1.6 MPa, 2.5 MPa, and 4.0 MPa.
Technical requirements
This standard specifies comprehensive technical requirements for the structural design, materials, and operational performance of fire pump siamese connections. The structure must ensure that residual water can be completely drained after use, and the internal minimum flow area shall not be smaller than the total flow area of the inlet fire interfaces. Regarding materials, the standard mandates specific metals based on the rated working pressure. For instance, bodies rated for 1.6 MPa must use grey cast iron (HT200 as specified in GB/T 9439), while higher pressure ratings of 2.5 MPa and 4.0 MPa require ductile iron (QT400-18 and QT450-10 respectively). Critical components like valve seats and stems must utilize copper alloys to ensure corrosion resistance and mechanical integrity. The standard also details requirements for sealing performance and hydrostatic strength. Connections must remain completely leak-free under their rated working pressure, and all castings must withstand 1.5 times the rated pressure without damage or leakage. Additionally, it sets precise criteria for safety valve opening pressures, handwheel dimensions, and the compatibility of fire interfaces.
Testing methods
The standard outlines specific testing procedures to verify compliance. Key tests include the sealing performance test, which evaluates leak resistance at rated working pressure for a duration of 2 minutes. The hydrostatic strength test subjects the unit to 1.5 times the rated pressure for 2 minutes to ensure structural integrity. Furthermore, it details the safety valve opening pressure test, which requires a slow and uniform pressure increase (not exceeding 0.01 MPa/s) to measure the valve's opening and closing pressure differential. Dimensional inspections for threads, handwheels, and opening heights are also conducted using precision instruments like vernier calipers.
FAQs
What products are regulated under GB 3446-2026?
This standard regulates various siamese connections used in fire protection piping systems, including above-ground, underground, wall-mounted, and multi-purpose types.
Are there any updates from the previous version of GB 3446?
The 2026 version introduces several major updates, including changes to the types, specifications, and model numbering of siamese connections. It also adds new requirements for connection methods, handwheels, and opening heights, while updating structural, material, and sealing performance criteria.
How does GB 3446-2026 differ from ISO standards?
The standard references several Chinese national standards (GB series) for materials, threads, and fire interfaces. Engineers should review the full translation to understand how these domestic requirements align with or differ from international ISO standards.
The summary above provides a high-level overview of GB 3446-2026. 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 3446-2026 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 3446-2013 (Current)