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IS 651:1992 is the Indian Standard (BIS) for salt glazed stoneware pipes and fittings. This standard provides specifications for the manufacture, dimensions, and testing of salt glazed stoneware pipes and fittings used for underground drainage and sewerage. Engineers use it to ensure proper quality control, hydraulic integrity, and structural strength of gravity sewer lines.
Covers requirements for salt glazed stoneware pipes and fittings primarily used for drainage and sewerage systems.
Overview
Status
Current
Usage level
Frequently Used
Domain
Environmental — Drainage, Sewerage and Sanitary Fittings
Consolidated list per BIS. For the text of each amendment, refer to the BIS portal link above.
salt glazed stonewareceramicsclay
International Equivalents
Similar International Standards
EN 295-1:2013CEN (Europe)
HighCurrent
Vitrified clay pipe systems for drains and sewers - Part 1: Requirements for pipes, fittings and joints
Covers requirements for vitrified clay pipes and fittings for gravity sewerage systems.
ASTM C700-21ASTM International (US)
HighCurrent
Standard Specification for Vitrified Clay Pipe, Extra Strength, Standard Strength, and Perforated
Specifies requirements for standard and extra strength vitrified clay pipes for gravity sewer lines.
BS 65:1991BSI (UK)
HighWithdrawn
Specification for vitrified clay pipes, fittings and ducts, also flexible mechanical joints for use solely with such pipes and fittings
Historically equivalent UK standard for vitrified clay pipes before adoption of European Norms.
AS 1741-1991Standards Australia (Australia)
HighWithdrawn
Vitrified clay pipes and fittings with flexible joints for sewerage applications
Former Australian standard for vitrified clay sewer pipes, now harmonized with EN 295.
Key Differences
≠IS 651 specifically mandates 'salt glazing', a particular manufacturing process. Modern standards like EN 295-1 and ASTM C700 are performance-based and specify surface characteristics (e.g., smoothness, impermeability) without mandating the glazing method, allowing for various ceramic glazes or even unglazed finishes.
≠Strength classification methods differ. IS 651 uses 'Grade A' and 'Grade AA'. ASTM C700 uses 'Standard Strength' and 'Extra Strength'. EN 295-1 uses a system of nominal crushing strengths (e.g., LN40, LN60) in kN/m, which is independent of pipe diameter.
≠The hydraulic pressure test (impermeability test) parameters are significantly different. IS 651 requires pipes to withstand 0.15 N/mm² (1.5 bar) for 5 seconds, whereas EN 295-1 specifies a test at a lower pressure of 0.5 bar but for a much longer duration of 15 minutes.
≠IS 651 is a comprehensive document covering pipes and a wide range of fittings (bends, junctions, traps). ASTM C700 focuses primarily on the pipes, with separate standards for testing (ASTM C301) and installation practices.
Key Similarities
≈All standards specify the same core material: vitrified clay, a ceramic material fired to a high temperature to achieve low water absorption and high chemical resistance.
≈The primary intended application across all standards is for the construction of gravity-flow drains and sewerage systems.
≈All standards mandate three fundamental performance tests: a crushing strength test for structural integrity, a water absorption/impermeability test for watertightness, and a chemical/acid resistance test to ensure durability.
≈All standards define dimensional and geometric tolerances for parameters like diameter, length, wall thickness, and deviation from straightness to ensure interchangeability and proper jointing.
Parameter Comparison
Parameter
IS Value
International
Source
Crushing Strength (min, for DN 150 pipe)
11 kN/m (Grade A)
20.4 kN/m (Standard Strength)
ASTM C700-21
Water Absorption (max, for pipes ≤300mm)
6.0%
8.0%
ASTM C700-21
Hydraulic Pressure Test
0.15 N/mm² (1.5 bar) for 5 seconds
0.05 N/mm² (0.5 bar) for 15 minutes
EN 295-1:2013
Acid Resistance (mass loss)
Max 3.0% loss
No simple % specified; must meet requirements when tested per referenced method (EN 12889).
EN 295-1:2013
Deviation from Straightness (max)
10 mm per 1000 mm length (e.g. 6mm for 600mm pipe)
10 mm per metre length
EN 295-1:2013
Strength Designation
Grade A, Grade AA
Standard Strength, Extra Strength
ASTM C700-21
⚠ Verify details from original standards before use