Значение и использование

4.1 Purpose of Guide G88—The purpose of this guide is to furnish qualified technical personnel with pertinent information for use in designing oxygen systems or assessing the safety of oxygen systems. It emphasizes factors that cause ignition and enhance propagation throughout a system's service life so that the occurrence of these conditions may be avoided or minimized. It is not intended as a specification for the design of oxygen systems.

4.2 Role of Guide G88—ASTM Committee G04’s abstract standard is Guide G128, and it introduces the overall subject of oxygen compatibility and the body of related work and related resources including standards, research reports and a video³ G04 has developed and adopted for use in coping with oxygen hazards. The interrelationships among the standards are shown in Table 1. Guide G88 deals with oxygen system and hardware design principles, and it is supported by a regulator ignition test (see G175).Other standards cover: (1) the selection of materials (both metals and nonmetals) which are supported by a series of standards for testing materials of interest and for preparing materials for test; (2) the cleaning of oxygen hardware which is supported by a series of standards on cleaning procedures, cleanliness testing methods, and cleaning agent selection and evaluation; (3) the study of fire incidents in oxygen systems; and (4) related terminology.

TABLE 1 Role of Guide G88 with Respect to Other ASTM G04 Standard Guides and Practices and their Supporting Test Methods^A, ^B

G128 Guide to Control of Hazards and Risks in Oxygen-Enriched
    Systems

 G88 Designing Systems for Oxygen Service

  G175 Evaluating the Ignition Sensitivity and Fault Tolerance of
      Oxygen Regulators

 

 G63 Evaluating Nonmetallic Materials

  D2512 Compatibility of Materials With Liquid Oxygen
       (Mechanical Impact)

  D2863 Measuring the Minimum Oxygen Concentration to Support
       Candle-Like Combustion (Oxygen Index)

  D4809 Heat of Combustion of Liquid Hydrocarbon Fuels by
       Bomb Calorimeter (Precision Method)

  G72 Autogenous Ignition Temperature of Liquids and Solids in
      High-Pressure Oxygen Enriched Atmospheres

  G74 Ignition Sensitivity of Materials to Gaseous Fluid Impact

  G86 Determining Ignition Sensitivity of Materials to Mechanical
      Impact in Pressurized Oxygen Environments

  G114 Aging Oxygen-Service Materials Prior to Flammability
      Testing

  G125 Measuring Liquid and Solid Material Fire Limits in Gaseous
      Oxidants

 G94 Evaluating Metals

  G124 Determining the Combustion Behavior of Metallic Materials
      in Oxygen Enriched Atmospheres

 G93 Cleaning Methods for Material and Equipment

  G120 Determination of Soluble Residual Contamination in
      Materials and Components by Soxhlet Extraction

  G136 Determination of Soluble Residual Contaminants in
      Materials by Ultrasonic Extraction

  G144 Determination of Residual Contamination of Materials and
      Components by Total Carbon Analysis Using a High
      Temperature Combustion Analyzer

  G127 Guide to the Selection of Cleaning Agents for Oxygen
      Systems

   G122 Test Method for Evaluating the Effectiveness of
       Cleaning Agents

    G121 Preparation of Contaminated Test Coupons for the
        Evaluation of Cleaning Agents

  G131 Cleaning of Materials and Components by Ultrasonic
      Techniques

 G145 Studying Fire Incidents in Oxygen Systems

 G126 Terminology Related to the Compatibility and Sensitivity of
     Materials in Oxygen-Enriched Atmospheres

Manual 36 – Safe Use of Oxygen and Oxygen Systems: Guidelines for Oxygen System Design, Materials Selection, Operations, Storage, and Transportation

^A ASTM D2863 is under the jurisdiction of Committee D20 on Plastics, and D4809 is under the jurisdiction of Committee D02 on Petroleum Products and Lubricants but both are used in the asessment of flammability and sensitivity of materials in oxygen-enriched atmospheres.^B ASTM Manual 36 – Safe Use of Oxygen and Oxygen Systems can be used as a handbook to furnish qualified technical personnel with pertinent information for use in designing oxygen systems or assessing the safety of oxygen systems. However, Manual 36 is not a balloted technical standard.

4.3 Use of Guide G88—Guide G88 can be used as an initial design guideline for oxygen systems and components, but can also be used as a tool to perform safety audits of existing oxygen systems and components. When used as an auditing tool for existing systems, Guide G88 can be applied in two stages: first examining system schematics/drawings, then by visually inspecting the system (that is, “walking the pipeline”). Guide G88 can be used in conjunction with the materials selection/hazards analysis approach outlined in Guides G63 and G94 to provide a comprehensive review of the fire hazards in an oxygen or oxygen-enriched system (1).⁵

Область применения

1.1 This guide applies to the design of systems for oxygen or oxygen-enriched service but is not a comprehensive document. Specifically, this guide addresses system factors that affect the avoidance of ignition and fire. It does not thoroughly address the selection of materials of construction for which Guides G63 and G94 are available, nor does it cover mechanical, economic or other design considerations for which well-known practices are available. This guide also does not address issues concerning the toxicity of nonmetals in breathing gas or medical gas systems.

Note 1—The American Society for Testing and Materials takes no position respecting the validity of any evaluation methods asserted in connection with any item mentioned in this guide. Users of this guide are expressly advised that determination of the validity of any such evaluation methods and data and the risk of use of such evaluation methods and data are entirely their own responsibility.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

1.3 This standard guide is organized as follows:

Section Title

Section

Referenced Documents

2

 ASTM Standards

2.1

 ASTM Adjuncts

2.2

 ASTM Manuals

2.3

 NFPA Documents

2.4

 CGA Documents

2.5

 EIGA Documents

2.6

Terminology

3

Significance and Use

4

 Purpose of G88

4.1

 Role of G88

4.2

 Use of G88

4.3

Factors Affecting the Design for an Oxygen or Oxygen-
 Enriched System

5

 General

5.1

 Factors Recognized as Causing Fires

5.2

  Temperature

5.2.1

  Spontaneous Ignition

5.2.2

  Pressure

5.2.3

  Concentration

5.2.4

  Contamination

5.2.5

  Particle Impact

5.2.6

  Heat of Compression

5.2.7

  Friction and Galling

5.2.8

  Resonance

5.2.9

  Static Electric Discharge

5.2.10

  Electrical Arc

5.2.11

  Flow Friction

5.2.12

  Mechanical Impact

5.2.13

  Kindling Chain

5.2.14

  Other Ignition Mechanisms

5.2.15

Test Methods

6

System Design Method

7

 Overview

7.1

 Final Design

7.2

 Avoid Unnecessarily Elevated Temperatures

7.3

 Avoid Unnecessarily Elevated Pressures

7.4

 Design for System Cleanness

7.5

 Avoid Particle Impacts

7.6

 Minimize Heat of Compression

7.7

 Avoid Friction and Galling

7.8

 Avoid Corrosion

7.9

 Avoid Resonance

7.10

 Use Proven Hardware

7.11

 Design to Manage Fires

7.12

 Anticipate Indirect Oxygen Exposure

7.13

 Minimize Available Fuel/Oxygen

7.14

 Avoid Potentially Exothermic Material Combinations

7.15

 Anticipate Common Failure Mechanism Consequences

7.16

 Avoid High Surface-Area-to-Volume (S/V) Conditions
  where Practical

7.17

 Avoid Unnecessarily-Elevated Oxygen Concentrations

7.18

 Anticipate Permutations from Intended System Design

7.19

 Avoid Designs and Failure Scenarios that can Introduce
  Potential Flow Friction Ignition Hazards

7.20

 Use Only the Most Compatible of Practical Materials
  and Designs

7.21

 Provide Thorough Safety Training for All Personnel
  Working with Oxygen or Oxygen-Enriched
  Components or Systems, including Design,
  Cleaning, Assembly, Operations, and
  Maintenance as Applicable to Personnel

7.22

 Miscellaneous

7.23

Examples

8

Key Words

9

References