GB/T 12552-2023Maximal safety depths for commercial diving (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/T 12552-1990 "Maximum Safe Depth for Industrial Diving": Compared with GB/T 12552-1990, except for structural adjustments In addition to general and editorial changes, the main technical changes are as follows:

a) The terms "nitrox saturation diving", "helium saturation diving", "tour diving" and "jet recirculation helium oxygen heavy diving equipment diving" have been deleted: Terms and definitions (see 2:4, 2:5, 2:6, and 2:7 of the:1990 edition);

b) Added the term and definition of "open diving bell" (see 3:4);

c) Delete the content related to breathing oxygen during diving (see 3:1 of the:1990 edition);

d) Changed the maximum safe depth requirements for self-contained air diving (see 4:1, 3:2:2 of the:1990 edition);

e) The maximum safe depth requirements for surface supplied air diving have been changed (see 4:2, 3:2:1 of the:1990 edition);

f) Added the maximum safe depth requirements for surface-supplied air diving using diving cages or open diving bells (see 4:3);

g) Delete the maximum limit for nitrox diving, air circuit diving during helium saturation diving, and diving using jet regenerative helium heavy diving equipment: Safety depth requirements (see 3:3:1, 3:3:3 and 3:4:1 of the:1990 edition);

h) Added the maximum safe depth requirements for mixed gas diving (see Chapter 5);

i) Changed the maximum safe depth requirements for helium-oxygen saturation diving (see 6:3, 3:4:2 of the:1990 edition);

j) Relevant content on basic requirements for diving gear and equipment configuration has been deleted (see Chapter 4 of the:1990 edition): This document is proposed and administered by the Ministry of Transport of the People's Republic of China: This document was drafted by: Shanghai Jiao Tong University Marine and Underwater Engineering Science Research Institute Co:, Ltd:, Shanghai Salvage Bureau of the Ministry of Transport, People's Republic of China PLA Naval Medical University, Guangzhou Diving School: The main drafters of this document: Xue Liqun, Huang Xin, Sun Jian, Zhang Guoguang, Xiao Xiaoling, Chen Ruiyong, Li Zhili, Chen Shuikai, He Xiuxia: This document was first published in:1990 and this is the first revision: Maximum safe depth for industrial diving

1 Scope

GB/T 12552-2023 is the Chinese national standard on maximal safety depths for commercial diving, in the field of services and company organization. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 27 November 2023 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 June 2024. Classification: ICS 03.220.40, CCS R53. 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 specifies the requirements for the maximum safe depth for air diving and mixed gas diving, as well as the maximum saturation depth for saturation diving: This document is applicable to industrial diving operations:

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text: Among them, the dated quotations For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document:

GB 26123 Air diving safety requirements

GB 28396 Safety requirements for mixed gas diving

3 Terms and definitions

The following terms and definitions as defined in GB 26123 and GB 28396 apply to this document: 3:1 industrial divingcommercialdiving commercial diving Diving operations that directly serve the national economy:

Note: Excludes military, emergency rescue, public safety, leisure, sports, technology, scientific research and other diving: 3:2 saturationdiving saturationdiving A diving method in which a diver is continuously exposed to a certain depth or pressure, and the tissues of the body are saturated with inert gas, and then decompressed and released into the water: [Source: JT/T 1452-2022, 3:3:6, with modifications] 3:3 diving cage divingcage;divingbasket A frame-type cage-shaped vehicle that transports divers to and from the surface and underwater working locations: [Source: JT/T 1452-2022,3:2:20] 3:4 open diving bellopenbel wet diving bell wetbel A carrier equipment that transports divers to and from the surface and underwater working sites: The upper end has a compressed gas environment, and the divers can The part above the shoulders is placed in it, and the remaining part is exposed to the water: [Source: JT/T 1452-2022, 3:2:13, with modifications]

4 Air diving

1 The maximum safe depth for self-contained air diving should be 30m: