GB/T 48043.1-2026Thermoplastic piping systems - Preliminary evaluation of the resistance to chemicals - Part 1: Test method (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents".

Drafting.

This document is Part 1 of GB/T 48043 "Preliminary evaluation of chemical resistance of thermoplastic piping systems". GB/T 48043 has been...

The following sections were published.

---Part 1: Test Methods;

---Part 2: Polyolefin Pipes and Components;

---Part 3: Rigid Polyvinyl Chloride (PVC-U), High-Impact Polyvinyl Chloride (PVC-HI), Modified Polyvinyl Chloride (PVC-M), Oriented Polyvinyl Chloride Polyvinyl chloride (PVC-O) and chlorinated polyvinyl chloride (PVC-C) pipes and components;

This document is modified to adopt ISO 4433-1:1997 "Thermoplastic pipes - Classification of resistance to liquid chemicals - Part 1: Immersion test".

Law".

This document has undergone the following structural adjustments compared to ISO 4433-1:1997.

---Chapters 3 and 9 have been added.

The technical differences between this document and ISO 4433-1:1997, and the reasons therefor, are as follows.

---The term "thermoplastic pipes" has been changed to "thermoplastic pipes, fittings, sheets/plates and valve components" (see Chapter 1) for better accuracy.

The practical application scope of this document;

---The soaking temperature has been changed, and "PA-U, ECTFE, PFA, PTFE" has been added, simplifying PE (LD, MD, HD) materials to...

PE, PVC(U,HI) is simplified to PVC (see Table 1, 8.4). The material list in the table only lists the major material categories, which is more in line with the classification.

Logicality;

---Generally, at least 4 mL of liquid should be used per square centimeter of the total sample area, or at least 60 mL of liquid per sample, to ensure adequate absorption.

The larger value shall prevail. This should be changed to "If the sample does not contain extractable or easily corrosive components, the volume of the test medium can be determined based on the total surface area of the sample." Calculate that at least 4 mL is used per square centimeter, or at least 30 mL per sample (whichever is greater). If at the test temperature...

If the chemical medium is gaseous, the air in the container should be purged first, and then the test medium should be added until the pressure reaches one standard atmosphere.

"Press." (See 8.6) to increase operability;

---Change "replace at least every 7 days" to "replace at least every 30 days" (see 8.8) to improve operability;

---The testing speeds for PA-U, ECTFE, PFA, and PTFE have been increased (11.3) to adapt to my country's technical conditions and enhance operability.

Actual nature;

---The statement "Different groups of samples should be used for tests a) and b)" has been revised (see 11.3) to improve logical coherence and operability;

---Added "c) Dimensional information of the specimen; g) Appearance changes;" (see Chapter 12), improving the test results and increasing operability.

Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents.

This document was proposed by the China National Light Industry Council.

This document is under the jurisdiction of the National Technical Committee on Standardization of Plastic Products (SAC/TC48).

Introduction

Thermoplastic piping systems are widely used and frequently need to transport or come into contact with various substances and their vapors, such as chemical products, fuels, and lubricants.

Under the influence of these chemical fluids, plastic piping systems may undergo two changes simultaneously. physical changes, such as the pipe walls absorbing the liquid.

The liquid swells, and soluble components in the pipe wall may be extracted into the liquid; chemical reactions may also affect the performance of the plastic piping system.

Significant changes may occur. These physical or chemical changes can also be caused by the internal and external stresses of the pipes, fittings, sheets, or valves used to transport the product.

It varies depending on the individual.

Stress refers to the stress per unit area caused by internal or external factors (such as temperature, changes, internal pressure, bending, and internal stress).

While cracking can occur, it can also induce cracking in products subjected to stress; this phenomenon is called environmental stress cracking. GB/T 43316 (all parts) establishes...

A method has been developed to evaluate the environmental stress cracking susceptibility of materials. This method can also be used to evaluate the environmental stress cracking resistance of polyolefin pipes.

GB/T 19279.

GB/T 11547 provides a test procedure applicable to the evaluation of chemical resistance of various plastic materials, but this method is not specific to thermoplastics.

Evaluation methods for pipes, fittings, sheets/plates, and valve components. Because the application conditions of plastic piping systems vary greatly, how to evaluate them...

It is very important to use simple and direct testing methods to make a preliminary judgment on its chemical resistance.

GB/T 48043 "Preliminary evaluation of chemical resistance of thermoplastic piping systems" is proposed to include the following 5 parts.

---Part 1: Test Methods. The aim is to establish preliminary methods for the chemical resistance of plastic pipes and their components.

---Part 2: Polyolefin Pipes and Components. The aim is to establish grading criteria and preliminary assessment of the chemical resistance of polyolefin pipes and components.

Evaluation methods.

---Part 3: Rigid Polyvinyl Chloride (PVC-U), High-Impact Polyvinyl Chloride (PVC-HI), Modified Polyvinyl Chloride (PVC-M), Oriented Polyvinyl Chloride Polyvinyl chloride (PVC-O) and chlorinated polyvinyl chloride (PVC-C) pipes and components. The purpose is to establish the pipes and components made of the aforementioned materials.

Grading criteria and preliminary evaluation methods for the chemical resistance of components.

---Part 4: Fluoropolymer Pipes and Components. The aim is to establish a classification standard for the chemical resistance of pipes and components made of the above materials.

Then and preliminary evaluation methods.

---Part 5: Rigid Polyamide (PA-U) Pipes and Components. The purpose is to establish the chemical resistance of pipes and components made of the above materials.

Grading criteria and preliminary evaluation methods.

This document is Part 1 of GB/T 43316 and is applicable to pipes, fittings, plates/sheets, or valve components manufactured under no-pressure or no-stress conditions (e.g., not subject to pressure).

This provides preliminary information on the suitability of transporting chemical media under soil loading, no dynamic stress, and internal stress conditions. The above evaluation results are applicable to pipe...

S (resistance to corrosion), L (limited resistance to corrosion), NS (not resistant to corrosion). Evaluation results for some plastics can be found in ISO/T R10358.

The above preliminary evaluation results are relatively reliable when the pipe wall stress is not high. However, if the pipe or fittings show preliminary chemical resistance to a certain substance...

The evaluation result is S or L. To further evaluate its chemical resistance when delivering the substance under pressure or other stresses, it is necessary to conduct further research.

Further testing, such as in the case of conveying pressurized fluids, can be performed using applicable test methods such as DIN 16463 to determine the effect of the chemical medium on the fluid.

The influence of long-term hydrostatic pressure strength on pressure plastic pipes.

This document does not take into account the effects of chemical media on the fatigue strength, impermeability, and resistance to rapid gas depressurization of the piping system.

Chemical resistance of thermoplastic piping systems Preliminary Evaluation Part 1: Test Methods Warning---Personnel using this document should have practical experience working in a formal laboratory. This document does not address all possible safety issues.

Users are responsible for taking appropriate safety and health measures and ensuring compliance with relevant national laws and regulations.

1 Scope

This document describes the preliminary chemical resistance assessment of thermoplastic pipes, fittings, sheets/plates, and valve components used for conveying chemical media.

The regulations specify the materials, testing instruments, specimens, immersion tests, tensile property tests, and test reports.

This document applies to pipes, fittings, plates/sheets, or valve components in the absence of pressure or stress (e.g., not subject to soil load, no dynamic stress, and...).

Preliminary evaluation of chemical resistance under internal stress conditions.

Note. Test methods for evaluating the compatibility of plastic materials with liquids, gases, gas-liquid mixtures or multiphase fluids under high pressure are specified in GB/T 34903.1.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are listed below.

For references to this document, only the version corresponding to that date applies. For undated references, the latest version (including all amendments) applies.

GB/T 1040.1 Determination of tensile properties of plastics - Part 1: General principles GB/T 1040.2 Determination of tensile properties of plastics – Part 2: Test conditions for molded and extruded plastics GB/T 8804.1 Determination of tensile properties of thermoplastic pipes – Part 1: General test methods GB/T 11547 Determination of the resistance of plastics to liquid chemical reagents GB/T 39812 Machining preparation of plastic specimens

3 Terms and definitions, abbreviations