Overview
ISO 7245:1984 establishes general specifications for acrylonitrile/butadiene/styrene (ABS) plastics used in the manufacturing of pipes and fittings through moulding and extrusion processes. Developed by ISO/TC 138 - the technical committee focusing on plastic pipes, fittings, and valves for fluid transport - this standard defines essential material properties to ensure consistent quality and performance in piping applications. It complements the ABS plastics designations and testing methods detailed in ISO 2580.
This standard is vital for manufacturers, contractors, and engineers working with ABS piping systems, providing a reliable framework for selecting materials based on their mechanical and thermal characteristics.
Key Topics
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Material Scope
Applies specifically to ABS plastics with acrylonitrile content ≥ 20% in the continuous phase. It excludes materials with more than 5% copolymers or flame retardants and those containing reinforcing fibers.
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Properties for Designation and Classification
The standard focuses on five key properties to classify and designate ABS plastics for pipes and fittings:
- Acrylonitrile content
- Vicat softening temperature
- Melt flow rate (hot fluidity index)
- Impact strength (Izod or Charpy notched test)
- Flexural modulus
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Testing Methods
Specifies standardized test methods referencing ISO standards such as ISO 178 (flexural properties), ISO 179 and ISO 180 (impact resistance), ISO 306 (Vicat softening temperature), and ISO 1133 (melt flow rate). Prescribed specimen preparation and conditioning ensure reliable and repeatable test results.
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Material Designation System
Includes a coding system identifying the ABS material by its physical properties suitable for piping applications, indicating properties like Vicat temperature range, melt flow rate limits, and mechanical strength grades.
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Physical and General Characteristics
Additional characteristics beneficial for application assessment include water absorption, thermal and weathering aging resistance, stress crack resistance, tensile properties, density (~1.06 g/cm³), thermal conductivity (~0.17 W/m·K), and coefficients of linear thermal expansion.
Applications
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Plastic Pipes and Fittings
ISO 7245:1984 guides manufacturers on selecting appropriate ABS materials for extruding or molding durable, reliable pipes and fittings used in water systems, drainage, ventilation, and industrial fluid transport.
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Quality Assurance in Production
Ensures materials meet minimum performance thresholds for temperature resistance, mechanical strength, and flow properties, leading to standardized products capable of withstanding typical service demands.
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Material Selection and Specification
Enables engineers and designers to specify ABS polymers with defined property ranges, streamlining procurement and ensuring compatibility with system requirements.
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Compatibility Considerations
Clarifies that identical material designations do not guarantee interchangeability, stressing the need for compatibility verification before mixing materials.
Related Standards
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ISO 2580 Series
Defines the designation and property determination methods specific to ABS plastics used in molding and extrusion, providing detailed testing protocols referenced by ISO 7245.
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ISO 178
Specifies methods for determining flexural properties of rigid plastics, critical for assessing ABS pipe material stiffness.
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ISO 179 and ISO 180
Describe impact testing methods for plastics using Charpy and Izod tests-essential for evaluating ABS toughness.
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ISO 306
Details the Vicat softening temperature test method, indicating the thermal resistance limit of ABS materials.
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ISO 1133
Provides the procedure for melt flow rate measurement, which informs processing parameters and material grade.
Summary
ISO 7245:1984 is an indispensable international standard that outlines the general specification for ABS plastics used in moulding and extrusion of pipes and fittings. By defining critical physical properties and standardized test methods, it ensures material consistency, mechanical integrity, and thermal performance-key factors for reliable ABS piping systems in various fluid transport applications. Awareness and application of this standard help manufacturers and engineers deliver high-quality, compliant plastic piping solutions worldwide.
Open preview (PDF)Pipes and fittings of acrylonitrile/butadiene/styrene (ABS) — General specification for moulding and extrusion materials