GB18435-2007
Breathing gases for divers and their determination methods
潜水呼吸气体及检测方法
GB 18435-2007 is a current mandatory Chinese national standard for Breathing gases for divers and their determination methods. It appears in the Machinery compliance cluster with a product safety focus and has an implementation date of Aug 1, 2007.
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 breathing gases for divers, specifically regulating the purity of compressed air, oxygen, nitrogen, and helium used in diving operations. It also sets maximum allowable limits for pollutants in saturation diving chamber environments. It is applicable to air diving, mixed gas diving, and saturation diving operations. Furthermore, it covers the design, manufacturing, and maintenance of associated diving systems, equipment, and breathing apparatus.
Technical requirements
Chapter 3 of this standard is mandatory and establishes strict purity thresholds for various gas sources. It specifies the required volume fractions of primary components and impurities, such as carbon monoxide, carbon dioxide, moisture (dew point), and oil mist, to ensure diver safety. Manufacturers and operators must strictly adhere to these purity parameters for all supplied breathing gases. The standard categorizes helium gas into two classes (Class A and Class B) based on purity levels. Class A is designated for conventional helium-oxygen diving and saturation diving at depths of 300m or shallower, while Class B is required for saturation diving exceeding 300m. Selecting the correct helium class based on operational depth is critical for compliance. Additionally, the standard defines the maximum allowable values for primary pollutant components in saturation diving chamber environments. This includes strict limits on toxic and hazardous gases such as ammonia, sulfur dioxide, hydrogen sulfide, and benzene. The standard emphasizes that the physiological impact of these pollutants depends on their partial pressure rather than just their concentration volume fraction, meaning concentration limits must be adjusted proportionally as diving depth and total pressure increase.
Testing methods
The standard outlines specific analytical procedures to validate gas purity and environmental safety. Key testing methods include gas chromatography for measuring carbon monoxide, carbon dioxide, and methane content. Moisture content is determined using the dew point method, while oxygen levels are analyzed using the copper-ammonium solution absorption method or specialized oxygen electrodes. For chamber environmental pollutants, the standard references various spectrophotometric methods, such as the methylene blue method for hydrogen sulfide and the Nessler reagent colorimetric method for ammonia. Testing for oil mist and particulate matter in compressed air must be conducted using the membrane sampling and gravimetric method detailed in the normative appendix.
FAQs
What products and applications are regulated under GB 18435-2007?
It applies to breathing gases used in air diving, mixed gas diving, and saturation diving. It also covers the design, manufacturing, and maintenance of associated diving systems, equipment, and breathing apparatus.
Which sections of GB 18435-2007 are mandatory?
Chapter 3, which specifies the purity requirements for breathing gases and the maximum allowable values for pollutants in saturation diving chambers, is mandatory. The remaining chapters and appendices are recommended.
Are there any significant updates from the previous version of this standard?
It replaces GB 18435-2001. The primary update is the addition of specific determination and testing methods for the breathing gases and chamber environmental pollutants, which were not fully detailed in the previous 2001 version.
The summary above provides a high-level overview of GB 18435-2007. To ensure complete compliance for your diving equipment and breathing gas systems entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 18435-2007 today to access all detailed parameter tables, testing procedures, and normative appendices.
Applicability hints
- Type
- Safety
- CCS
- R53
- ICS
- 03.220.40
- Competent department
- Ministry of Transport
- Technical committee
- Ministry of Transport
Relationships
Replaces:GB 18435-2001