GB 20826-2021Code of safety for the use of high pressure water jetting equipment by divers (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB 20826-2007 "Safety Regulations for Diver High Pressure Water Jet Operations", compared with GB 20826-2007, except for editing In addition to the changes, the main technical changes are as follows:

--- Deleted the terms and definitions of unloading water guns and intercepting water guns (see

2.4 of the.2007 edition);

---Modified the terms and definitions of high-pressure water jet and high-pressure water gun (see

2.2 of the.2007 edition);

---The terms and definitions of ultra-high pressure water jets have been added (see 3.2);

---Modified the requirements of environmental conditions (see Chapter 4, Chapter 3 of the.2007 edition);

---Modified the equipment requirements for high-pressure hoses, spray booms and high-pressure water guns (see

5.2 and 5.3, 4.2,

4.3 and the.2007 edition 4.4);

---Added the requirements for the provision of divers (see 6.1.1.2);

---Modified diving supervision requirements (see 6.1.2,

5.1.1 of the.2007 edition);

---Modified the requirements for training and operation protection (see

1 Scope

GB 20826-2021 is the Chinese national standard on code of safety for the use of high pressure water jetting equipment by divers, in the field of services and company organization. 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 10 August 2021 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 March 2022. Classification: ICS 03.220.40, CCS R54. 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 standard specifies the environmental conditions, equipment requirements, personnel requirements, operating procedures, and maintenance guarantees for divers to implement underwater high-pressure water jet operations. Raising and storage, injury and emergency treatment. This standard applies to underwater high-pressure and ultra-high-pressure water jet operations performed by divers in the field of rescue and salvage.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 24555-2009.200m helium-oxygen saturation diving operation requirements

GB 26123 Air diving safety requirements

GB 28396 Safety requirements for mixed gas diving

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 Highpressurewaterjetting The working pressure is 10MPa~170MPa, and high-speed water streams of different shapes are formed by the nozzles.

3.2 Ultrahighpressurewaterjetting The working pressure exceeds 170MPa, and high-speed water streams of different shapes are formed by the nozzles.

3.3 Highpressurejettinggun A water jet device composed of a control valve, a gun barrel and a nozzle assembly (including one or more nozzles).

Note. According to the type of control valve, the high-pressure water gun can be divided into two types. unloading type and intercepting type. When the control valve is closed, the high-pressure water is released and divided through the overflow port of the safety valve The water jet device that goes to the water environment is called an unloading water gun (dumpgun); when the control valve is closed, the high-pressure water remains in the water supply pipe of the water jet system The water jet device in the line is called a shutoff gun.

3.4 Flexiblebuckle A ring-shaped connection is made at the end joints of two connected hoses with flexible materials such as short steel wire ropes or cables.

4 Environmental conditions

4.1 Self-contained air diving underwater high-pressure water jet operations should meet the requirements of GB 26123.The water flow speed should not be greater than 0.5m/s, Beaufort The wind level should not be greater than level 4 (wind speed 5.5m/s~7.9m/s, wave height 1.0m).

4.2 Surface-supplied air diving high-pressure water jet operations, when entering the water through the diving ladder, should meet the requirements of GB 26123.Water flow speed should