GB 3446-2026Siamese connection (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. This document replaces GB 3446-2013 "Fire Pump Connection". Compared with GB 3446-2013, the main differences are structural adjustments and editorial changes. In addition, the main technological changes are as follows:

a) The type and specifications of the fire pump connection have been changed (see 4.1,.2013 edition of 4.1);

b) The model designation for fire pump connections has been changed (see 4.2,.2013 version 4.2);

c) The structural requirements and test methods for fire pump connections have been changed (see

5.1 and 6.1,.2013 editions of

d) The material requirements and test methods for fire pump connections have been changed (see

5.2 and 6.2,.2013 editions of

e) The appearance quality requirements for fire pump connections have been changed (see 5.3,.2013 version 5.3);

f) The thread and flange size requirements and test methods for fire pump connections have been changed (see

5.4 and 6.4,.2013 edition of

5.4 and 6.4). 6.4);

g) Added requirements for the connection method of fire pump connections (see 5.5);

h) Added requirements and test methods for the handwheel of the fire pump connection (see

1 Scope

GB 3446-2026 is the Chinese national standard on siamese connection, in the field of environment and health protection, safety. It carries no /T suffix, which in the Chinese system means compliance is mandatory: a product or a practice within its scope has to meet it to be lawfully made, sold or carried out in China. It was issued on 28 January 2026 by the State Administration for Market Regulation; Standardization Administration of China, and takes effect on 1 February 2027. Classification: ICS 13.220.10, CCS C84. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This document defines the terminology for fire pump connections, specifies their classification, technical requirements, inspection rules, marking, and packaging, and describes the corresponding... The experimental method. This document applies to various fire pump connections in fire protection pipelines.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 197 Tolerances for Standard Threads

GB/T 1176 Cast copper and copper alloys

GB/T 1348 Ductile Iron Castings

GB/T 1804-2000 General tolerances - Tolerances for linear and angular dimensions without specified tolerances

GB/T 4423 Copper and Copper Alloy Drawing Rods

GB 5135.11 Automatic sprinkler systems - Part

3 Terms and Definitions

The following terms and definitions apply to this document.

3.1 Fixed outside the building, used by fire trucks or motorized pumps to deliver fire-fighting water and other liquids to the building's fire water supply system. Connecting devices for propellants.

Note. This document is referred to as the connector.

11 Grooved pipe fittings

GB/T 7307 55° Non-sealing pipe thread

GB/T 9124.1 Steel pipe flanges - Part 1: PN series

GB/T 9439 Gray Cast Iron Parts

GB 12514 (all parts) Fire Protection Connections

GB/T 17241.1 Cast iron pipe flanges - Part 1: PN series JB/T 7273.3 Handwheel