The 1986 standard delineates specifications for pitch-treated fibre pipes and associated fittings chiefly utilized in drainage systems, encompassing perforated variants for subsurface drainage. It details the criteria for materials, dimensions, joint configurations, mechanical and chemical testing protocols, and marking standards to guarantee performance, leak-proof joints, and adaptability for diverse drainage needs. The guideline serves manufacturers, engineers, and quality assurance personnel responsible for the manufacturing, installation, and evaluation of drainage piping.
Overview
The 1986 standard delineates specifications for pitch-treated fibre pipes and associated fittings chiefly utilized in drainage systems, encompassing perforated variants for subsurface drainage. It details the criteria for materials, dimensions, joint configurations, mechanical and chemical testing protocols, and marking standards to guarantee performance, leak-proof joints, and adaptability for diverse drainage needs. The guideline serves manufacturers, engineers, and quality assurance personnel responsible for the manufacturing, installation, and evaluation of drainage piping.
Audience
Contents
Structure
Overview of IS 11925 detailing key specifications and tabulated data.
Material requirements for polypropylene fittings include black isotactic polypropylene polymers or copolymers with stabilizers, lubricants, and fillers. Minimum body wall thickness values are stipulated in a dedicated table.
Summary of vital tables covers taper coupling joints, snap ring joints, 'O' ring joints, and spigot and socket joint dimensions with nominal bore ranges and corresponding key measurements.
This standard governs the dimensional, material, and tolerance requirements for polypropylene pipes and fittings designed for pressure-based drainage applications.
Includes detailed tables specifying material composition, pipe dimensions, and joint parameters such as coupling length, pipe joint length, initial gap, and wall thickness for varying nominal bores.
Clarification of terms related to pipe fittings, joint types, and material composition.
Defines polypropylene fittings as black components manufactured from isotactic polypropylene polymers or copolymers with additives to enhance performance.
Includes summary tables outlining critical dimensions for taper coupling joints, snap ring joints, 'O' ring joints, and spigot and socket fittings.
Describes material requirements for polypropylene fittings, emphasizing black isotactic polypropylene or copolymer materials with stipulated minimum wall thickness.
Dimensional data tables specify coupling lengths, pipe joint lengths, initial contact gaps, and coupling wall thicknesses across various nominal bore sizes.
Details test requirements for mechanical strength including load and deflection parameters.
Specifies pipe internal diameter limits ensuring circular cross-section conformity.
Details taper coupling joint dimensions including coupling length, pipe joint length, initial gap, and coupling wall thickness specific to polypropylene fittings for each nominal bore.
Outlines snap ring joint dimensions for nominal bores between 75 and 150 mm.
Details taper coupling joint measurements such as length, joint length, gap, and wall thickness for both impregnated fibre and polypropylene fittings.
Provides snap ring joint dimension specifications including socket and throat diameters for nominal bores ranging from 75 to 150 mm.
Specifies material composition and body wall thickness requirements for fittings based on nominal bore size differentiating between below and above ground use.
Includes taper coupling joint dimensional data covering coupling length, pipe joint length, initial contact gap, and coupling wall thickness for impregnated fibre components.
Summarizes key mechanical tests for pipes and fittings including beam strength and deflection tests performed at controlled speeds and temperatures.
Describes flattening resistance tests with oven conditioning and diameter change limits.
Details impact test procedures for complete fittings and weld line tensile strength assessments.
Outlines marking requirements mandating manufacturer identification and batch numbers on pipes, couplings, and fittings.
Explains regulatory framework for using the BIS standard mark under the Bureau of Indian Standards Act, including licensing procedures and contact details for regional offices.
Includes summary of flattening test loads and acceptance criteria.
Provides comprehensive dimensional tables for various joint types including taper coupling, snap ring, and 'O' ring joints.
Lists precise measurements for coupling lengths, pipe joint lengths, initial gaps, and coupling wall thicknesses for different nominal bore sizes.
Frequently Asked
IS 11925 (1986) specifies that the pipes are made from a preformed felted fibrous base impregnated with pitch, bitumen, or other suitable compounds that fulfill performance criteria outlined in the standard. This impregnation ensures the pipes are water-resistant and chemically durable, suitable for drainage applications.
The standard encompasses soil pipe 'O' ring joints, snap ring joints, spigot and socket or rebated joints, among others. Water-tightness is guaranteed through the use of compliant rubber seals like 'O' rings and snap rings, plus rigorous hydrostatic testing under a 6-meter water head for one hour, including static head, straight draw, deflection, and shear resistance tests without leakage.
Mechanical verification involves crushing strength tests on dry, wet, and kerosene-conditioned specimens, static head and straight draw tests for joints, deflection tests under angular displacement, shear resistance tests, and weld line tensile strength assessments. These tests ensure the components meet or exceed minimum load and deflection criteria specified for each nominal bore.
Chemical resistance is evaluated primarily through immersion tests in kerosene for ten days followed by mechanical strength testing. Adhesives used in fittings must resist chemical attack and boiling water, verified through specific tests. Additionally, heat resistance tests ensure no distortion or exudation occurs at elevated temperatures, confirming stability under chemical and thermal stresses.
The standard mandates a pipe length tolerance of ±10 mm per meter, measured on the inside curve with a 1-meter straight edge. Coupling dimensions such as length, pipe joint length (±0.25 mm), initial contact gap, and wall thickness have defined minimum and maximum limits varying by nominal bore. Spigot lengths have a tolerance of +2.5 mm. These tolerances ensure proper fit and sealing performance.
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