Standard No.:	GB/T 13465.11-2025
English Name:	Test method of impermeable graphite materials—Part 11:Penetration coefficient
Chinese Name:	不透性石墨材料试验方法 第11部分：渗透系数
Chinese Classification:	G94    Non-metal chemical machinery equipment
Professional Classification:	GB    National Standard
Source Content Issued by:	SAMR; SAC
Issued on:	2025-8-29
Implemented on:	2026-3-1
Status:	to be valid
Target Language:	English
File Format:	PDF

GB/T 13465.11-2025 Test method of impermeable graphite materials—Part 11:Penetration coefficient English, Anglais, Englisch, Inglés, えいご This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered. ICS 71.120 CCS G 94 People's Republic of China National Standard GB/T 13465.11-2025 Test Method of Impermeable Graphite Materials - Part 11: Penetration Coefficient Issued on August 29, 2025; Implemented on March 1, 2026 Issued by State Administration for Market Regulation Standardization Administration of China Contents Foreword Introduction 1 Scope 2 Normative References 3 Terms and Definitions 4 Test Principle 5 Test Apparatus and Instruments 6 Test Specimens 7 Test Procedure 8 Result Calculation and Processing 9 Test Report Test Method of Impermeable Graphite Materials - Part 11: Penetration Coefficient 1 Scope This document describes the test method for measuring the penetration coefficient of impermeable graphite materials using the vacuum attenuation method. This document applies to the testing of the penetration coefficient of impermeable graphite materials with a penetration coefficient ranging from 1×10⁻⁶ mm²/s to 1 mm²/s under natural environmental conditions using air as the test gas. 2 Normative References The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, subsequent amendments (excluding勘误表) or revisions apply. For undated references, the latest edition of the document (including any amendments) applies. GB/T 13465.1 Test Method of Impermeable Graphite Materials - Part 1: General Principles HG/T 2059 Technical Requirements for Impermeable Graphite Tubes 3 Terms and Definitions The following terms and definitions apply to this document. 3.1 Penetration Coefficient The amount of gas permeation per unit time and per unit area through a certain volume and length of impermeable graphite tubular test specimen. 3.2 Vacuum Attenuation Method A method for calculating the gas penetration coefficient of a tubular test specimen by measuring the pressure difference before and after a certain period of standing in a natural environment after evacuating a sealed container to a certain pressure value. 4 Test Principle The measurement is performed using the vacuum attenuation method. The impermeable graphite tubular test specimen is installed on the test apparatus to form a sealed container. The container is then evacuated to a certain pressure value. After standing for a set time in a natural environment, the pressure difference before and after standing is measured to calculate the penetration coefficient of the impermeable graphite tubular test specimen.