Glazed Fire-Clay Sanitary Appliances: Part-1 General Requirements
1979 Edition

Overview (Clause 2.0)

• Defines key terminology related to vitreous china sanitary products.
• Applies to the manufacture and quality control of these appliances.

Defect and Performance Limits (Clause 8.1, Table 1)

• Warpage tolerance: ±2% of dimension or 10 mm max.
• Limits on spots, blisters, bubbles, pinholes, polishing marks with specified maximum counts depending on location.

Warpage Assessment (Clause 6.1)

• Use of feeler gauge equal to maximum allowed warpage.
• Appliance passes if gauge does not slide in without resistance.

Rounding Off Rules (Clause 0.3)

• Test results rounded following IS 2:1960 standards, preserving significant figures.

This section ensures dimensional and surface quality adherence as per IS 771 Part 1.

Definitions (Clause 2.0)

• Provides uniform terms for sanitary appliances, surface blemishes, defects, and performance standards.

Allowable Defects and Blemishes (Clause 8.1, Table 1)

• Specifies maximum permitted quantities for various defects by location, such as warpage, spots, bubbles, pinholes, polishing marks.

Testing and Rounding (Clauses 2.3 & 0.3)

• Sampling sizes depend on batch size.
• Test values rounded per IS 2:1960 norms.

This section standardizes defect terminology and quality control limits.

Material and Manufacturing Defects (Clause 8.1, Table 1)

• Warpage: ±2% or 10 mm max.
• Spots and blisters: Up to 6.
• Bubbles, pinholes, specks: Up to 8 in service areas.
• Polishing marks and exposed bodies: Up to 4.

Surface Finish Quality

• Wavy glaze or mottled appearance is unacceptable.
• Stain and burn resistance verified as per Appendix B.

Inspection and Testing (Clause 2.3)

• Sample sizes and compliance depend on lot size.
• Manufacturer must certify conformity.

Warpage Limit Formula:

Max Warpage = minimum of ±2% dimension or 10 mm.

This section ensures product quality through material and finishing standards.

Thickness Specifications (Clause 4.1)

• Minimum thickness for any part of the appliance is 8 mm.

Warpage Limits (Clause 6.1 & Table 1)

• Checked with feeler gauge; must not slide in without force.

Inspection Parameters (Clause 2.5)

• Checks include finish, thickness, dimensions, glazing, and warpage.

This ensures strength and dimensional accuracy in sanitary appliances.

Sampling and Testing (Clauses 2.3, 2.5, 1.1)

• Eight test specimens (≥75 x 25 x 8 mm) selected from glazed surfaces.
• One specimen retained as control.
• Tests include finish, thickness, dimensions, glazing quality, and warpage.
• Defects in any test render appliance defective.

Warpage Tolerance

• Maximum ±2% dimension or 10 mm.

Defect Limits (Clause 8.1, Table 1)

• Spots and blisters, bubbles, pinholes, polishing marks with specified maximum numbers depending on location.

This section ensures glazing uniformity and durability.

Defect Limits (Clauses 3.2 & 8.1, Table 1)

• Warpage: ±2% or 10 mm max.
• Spots and blisters: Up to 6 generally.
• Bubbles, pinholes, specks: Up to 8 in service spaces.
• Polishing marks and exposed bodies: Up to 4.
• Visible surfaces have stricter limits per pottery square.

Inspection Method

• Visual examination within specified viewing circle by trained observer without aids.

This section defines permissible cosmetic defects ensuring functionality and aesthetics.

Process Inspection (Appendix C, Clause 1.1)

• Continuous monitoring during production to maintain consistent quality.
• Sampling frequency varies with kiln type (continuous or intermittent).

Inspection Frequency Examples

• Visual and warpage checks on every unit.
• Thickness and dimension checks on periodic samples.
• Specialized tests like water absorption, crazing, chemical resistance done on defined sample sizes.

Documentation

• Manufacturer provides inspection data for purchaser acceptance.
• Statistical quality control recommended.

This ensures systematic quality assurance throughout production.

Inspection Techniques (Clause 7.1, Appendix C)

• Sampling based on lot size.

Chemical Resistance Test (Clause 8.5, Appendix A)

• Tests durability of glaze against specified chemicals.

Conformance Criteria (Clauses 2.3 & C-2.3)

• Number of tests depends on batch size.
• Covers finish, thickness, dimensions, glazing, warpage.

Permitted Defects Summary (Clause 8.1, Table 1)

• Warpage ±2% or 10 mm.
• Various defect types with maximum allowed counts.

This section outlines test procedures ensuring compliance with the standard.

Process Inspection (Appendix C, Clause 7.1)

• Visual examination and warpage on every unit.
• Dimensional checks on sample basis depending on kiln type.
• Water absorption, crazing, chemical resistance, staining, rupture modulus, and thermal shock tests performed at defined frequencies.

Defect Limits

• Warpage and blemish thresholds as per Table 1.

This section defines inspection setups and defect acceptance for quality control.

Defect Allowances (Clause 8.1, Table 1)

• Warpage: ±2% or 10 mm.
• Spots and blisters: Up to 6 generally.
• Bubbles, pinholes, specks: Up to 8 in service areas.
• Polishing marks: Up to 4.

Polishing Mark Definition (Clause 2.10)

• Minor blemish polished out, max diameter 10 mm.

Rounding Off (Clause 0.3)

• Test values rounded according to IS 2-1960, maintaining significant digits.

This section ensures correct marking and defect categorization on sanitary ware.

Process Inspection (Appendix C, Clauses 7.1 & 1.1)

• Aim: Preserve consistency and minimize variations.
• Sample selection at regular intervals.

Inspection Frequencies

• Visual, warpage: every unit.
• Thickness, dimensions: periodic samples.
• Water absorption, crazing, chemical resistance, staining, rupture modulus, thermal shock: sampled at defined intervals based on kiln type.

Batch Inspection

• Conducted by purchaser to verify compliance.
• Manufacturer provides test data for acceptance.
• Statistical quality control methods encouraged.

This appendix outlines quality control practices during production and acceptance.