GB/T 42368-2023 (English Version)

Standard No.: GB/T 42368-2023
Language: Chinese, Available in English version
Release Date: 2023
Published By: General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
Latest: GB/T 42368-2023

Scope: This document describes the method for determining the explosion limits of a combustible mixture of combustible gas (vapor) and air under given initial temperature and initial pressure conditions. This document is applicable to the determination of the explosion limits of combustible gas (vapor) under the conditions of an initial temperature below 200 degrees Celsius, an initial pressure below 1.0 MPa (absolute pressure), and a maximum explosion pressure not greater than 15.0 MPa (absolute pressure). This document is not applicable to the determination of the explosion limits of chemically unstable gases or mixed gases whose components react with each other.

Introduction

1. Background of standard formulation and analysis of technological evolution

The determination of the explosion limit of flammable gases under high temperature and high pressure conditions is of great significance for the safe production of industries such as petrochemicals. With the advancement of industrial technology, traditional experimental methods have gradually exposed their limitations under complex working conditions. The formulation of GB/T 42368-2023 fills the gap in this field and provides a more accurate and safer testing solution.

2. Comparative analysis of standard frameworks

Standard dimensions	GB/T 42368—2023	Internationally accepted standard	Old standard (such as GB/T 12474)
Applicable temperature range	≤200°C	≤150°C	Normal temperature environment
Upper limit of test pressure	1.0MPa (absolute pressure)	0.5MPa (absolute pressure)	No clear restrictions
Explosion limit calculation method	Based on the percentage change of pressure increment	Direct determination of volume fraction	Single concentration point analysis

3. Practical application case analysis

Case 1: Methane gas test in a petrochemical enterprise

In actual operation, a petrochemical enterprise tests the explosion limit of methane under high temperature and high pressure conditions. According to the standard requirements, the experimental device uses a spherical stainless steel explosion tank (20L), the initial temperature is set to 180°C, and the initial pressure is 0.5MPa.

During the test, by gradually changing the methane concentration, the maximum pressure change after each ignition is recorded. Finally, it is concluded that under this working condition, the lower explosion limit of methane is 2.8% and the upper explosion limit is 45%.

4. Implementation recommendations

Equipment selection:Select an explosion reaction vessel of appropriate volume and material (such as 5L, 12L, 20L, etc.) according to specific test requirements. For high-risk gases, it is recommended to use a stainless steel container with a larger diameter.
Temperature control:Ensure that the temperature control unit can stably maintain the set temperature. It is recommended to use a thermal oil heating system to improve uniformity and smoothness.
Safety protection:Set up explosion-proof barriers and remote ignition devices in strict accordance with standard requirements. Operators should be located in a safe area and equipped with necessary emergency supplies.

GB/T 42368-2023 Referenced Document

GB/T 12474 Method for Determination of Explosive Limits of Combustible Gases in Air
GB/T 16425 Determination for minimum explosive concentration of dust clouds
GB/T 21844 Standard test method for concentration limits of flammability of chemicals(vapors and gases)

GB/T 42368-2023 history

2023 GB/T 42368-2023 Method for Determination of Explosive Limits of Combustible Gas (Steam) under High Temperature and High Pressure Conditions