Method for a sampling of vitreous and fire clay sanitary appliances

IS 9140: Scope & Sampling Specifications

Scope (Clause 3.0)

• Defines key terms and applicability of the standard.
• Covers testing and conformity criteria for appliances (e.g., warpage, dimensional accuracy, construction, flushing, cleanability).

Sampling & Acceptance Criteria

Table 1: Non-destructive Tests (Clause 5.1.1)

Table 2: Warpage, Dimensional, Construction, Flushing, Cleanability (Clause 5.1.2)

Key Notes:

• Acceptance No. = Max number of defective units allowed in sample.
• Sampling size increases with lot size to ensure quality control.
• Applies to non-destructive and functional tests.

This ensures appliances conform to quality standards before acceptance.

IS 9140 - Key Definitions and Sampling Specifications

Definitions (Clause 3.0)

• The standard defines terms related to sanitary appliances and testing procedures.
• Definitions ensure uniform understanding for sampling, acceptance, and testing.

Sampling & Acceptance (Clause 5.1.2 & 5.1.2.2)

• Lot conformity: Lot is accepted if defectives ≤ acceptance number.

Testing Requirements

• Non-destructive tests: As per Table 5.1, sample size and acceptance criteria apply.
• Destructive tests (Clause 5.2.3): Lot conforms if all tests meet specifications.

Referenced IS Standards (Annex A)

• IS 397: Statistical quality control methods.
• IS 2556 (Parts 1-15): Specifications for vitreous sanitary appliances.
• IS 4905: Methods for random sampling.

Summary Diagram: Sampling & Acceptance Process

flowchart TD
    A[Start: Lot of Appliances] --> B{Lot Size?}
    B -->|≤ 90| C[Sample 5]
    B -->|91-150| D[Sample 8]
    B -->|151-500| E[Sample 13]
    B -->|501-2000| F[Sample 20]
    C --> G{Defectives ≤ 0?}
    D --> G
    E --> G
    F --> H{Defectives ≤ 1?}
    G -->|Yes| I[Lot Accepted]
    G -->|No| J[Lot Rejected]
    H -->|Yes| I
    H -->|No| J

This ensures quality control through statistically valid sampling and acceptance criteria.

IS 9140 Sampling Procedures for Sanitary Appliances

Sampling is based on IS 2500 (Part 1):1992, using Attribute Sampling Plans indexed by Acceptance Quality Level (AQL) for lot-by-lot inspection.

Key Tables for Sampling & Acceptance

Table 1: Sampling for Clause 5.1.1 (General Sampling)

Table 2: Sampling for Clause 5.1.2 (Non-destructive Tests)

Usage Notes:

• Acceptance Number (Ac): Maximum allowable defective samples to accept the lot.
• Sampling size increases with lot size to maintain inspection reliability.
• Zero acceptance number means no defect is allowed in the sample.

Summary:

• Sampling ensures economic, rational, and objective evaluation of sanitary appliances.
• Helps in quality control and consumer protection.
• Based on Attribute Sampling Plans from IS 2500.

flowchart LR
    LotSize[Lot Size] --> SampleSize[Determine Sample Size from Table]
    SampleSize --> Inspection[Inspect Sample]
    Inspection -->|Defects ≤ Acceptance No.| Accept[Accept Lot]
    Inspection -->|Defects > Acceptance No.| Reject[Reject Lot]

This flow ensures consistent quality control per IS 9140.

IS 9140: Process Control Key Points

1. Statistical Quality Control

• Recommended use of Statistical Quality Control (SQC) techniques.
• Refer to IS 397 (Parts 1, 2 & 3) for detailed SQC guidance.

2. Acceptance Number (Clause 3.7)

• Defines the maximum permissible defectives in a sample for lot acceptance.

3. Inspection Frequency (Clause 4.3)

Summary Table (Inspection Frequency)

IS 9140 - Lot Inspection Key Points

Visual Inspection (Clause 5.1.1.2)

• Lot accepted if defectives ≤ acceptance number from Table 1 (not provided here).

Non-Destructive Tests (Clause 5.1.2.2)

• Lot accepted if defectives ≤ acceptance number from Table 2 below.

Table 2: Sampling & Acceptance Number for Non-Destructive Tests

Notes:

• Sampling plan based on IS 2500 (Part 1):1992.
• Acceptance Quality Level (AQL) concept used.
• If defectives in sample > acceptance number, reject the lot.

flowchart TD
    A[Start: Lot Inspection] --> B{Select Sample Size}
    B -->|Lot ≤ 90| C[Sample = 5, Accept if defects ≤ 0]
    B -->|91 ≤ Lot ≤ 150| D[Sample = 8, Accept if defects ≤ 0]
    B -->|151 ≤ Lot ≤ 500| E[Sample = 13, Accept if defects ≤ 0]
    B -->|501 ≤ Lot ≤ 2000| F[Sample = 20, Accept if defects ≤ 1]
    C --> G{Defects ≤ Acceptance No.?}
    D --> G
    E --> G
    F --> G
    G -->|Yes| H[Accept Lot]
    G -->|No| I[Reject Lot]

This ensures consistent quality control using attribute sampling.

IS 9140 - Non-destructive Tests (Clause 5.1)

Key Tests (Clause 5.1):

• Visual Inspection: Check permissible blemishes, defects, finish, marking, warpage, dimensions, and construction.
• Flushing and Cleanability Test: Applicable where required to ensure cleanliness.

Sampling & Acceptance Criteria

Table 1: Sampling for Non-destructive Tests (Clause 5.1.1)

Table 2: Sampling for Non-destructive Tests (Clause 5.1.2)

Summary:

• No damage is caused during these tests.
• Sampling size and acceptance numbers depend on lot size.
• Acceptance numbers indicate the maximum allowable defective items in the sample.

flowchart TD
    A[Lot of Appliances] --> B{Lot Size}
    B --> |Small Lot| C[Sample Size & Acceptance No. from Table 1]
    B --> |Large Lot| D[Sample Size & Acceptance No. from Table 2]
    C --> E[Perform Visual & Cleanability Tests]
    D --> E
    E --> F{Defects Found ≤ Acceptance No.?}
    F --> |Yes| G[Lot Accepted]
    F --> |No| H[Lot Rejected]

Use these tables and criteria to plan and assess

IS 9140 - Destructive Tests (Clause 5.2)

Destructive tests ensure product quality by physically testing samples to failure or damage. Key tests include:

• Minimum Thickness: Verify the product meets the specified thickness to ensure durability.

• Crazing: Check for fine cracks on the surface indicating stress or aging.

• Water Absorption: Measure % weight gain after immersion to assess porosity.

• Chemical Resistance: Expose to chemicals and observe degradation.

• Resistance to Staining and Burning: Evaluate surface integrity after exposure.

• Modulus of Rupture (MOR): Determines flexural strength, calculated by:

  [ MOR = \frac{3PL}{2bd^2} ]

  where:

  • (P) = Load at fracture (N)
  • (L) = Span length (mm)
  • (b) = Width of specimen (mm)
  • (d) = Depth/thickness of specimen (mm)

• Thermal Shock: Assess resistance to sudden temperature changes.

Sampling for Tests (From Clause 5.1.2 Table 2)

Note: Destructive tests are usually performed on samples selected per the above sampling plan to ensure reliability without testing every unit.

IS 9140: Criteria for Conformity - Key Points

1. Sampling & Acceptance Criteria

• Sample size depends on lot size (see Col 1 & 2).
• Equal number of appliances from each size.
• If sizes > sample size, take at least one from each size; total sample size may increase.
• Use acceptance number from Col 3 to decide conformity.

2. For Warpage, Dimensional, Construction, Flushing & Cleanability Tests

• Lot conforms if defectives ≤ acceptance number in Table 2.

Summary Formula for Conformity:

• Lot conforms if:
  [ \text{Number of defectives} \leq \text{Acceptance Number (from Table 1 or 2)} ]

Sampling Process (Mermaid Diagram)

flowchart TD
    A[Start: Identify Lot Size] --> B[Determine Sample Size from Table 1]
    B --> C{Number of Sizes > Sample Size?}
    C -- Yes --> D[Select at least 1 appliance from each size]
    D --> E[Total sample size may increase]
    C -- No --> F[Select equal number from each size]
    E --> G[Conduct Visual Inspection]
    F --> G
    G --> H[Count Defectives]
    H --> I{Defectives ≤ Acceptance Number?}
    I -- Yes --> J[Lot Conforms]
    I -- No --> K[Lot Does Not Conform]

Note: Refer to IS 9140 Tables 1 & 2 for exact sample sizes and acceptance numbers based on lot size and test type.

IS 9140: Acceptance Numbers and Sample Sizes

Key Definitions:

• Acceptance Number (Clause 3.7): Maximum permissible defectives in a sample to accept the lot.

Sampling & Acceptance for Non-Destructive Tests

Table 1 (Clause 5.1.1)

Table 2 (Clause 5.1.2 and 5.1.2.2)

Acceptance Criteria (Clause 5.1.2.2)

• Lot is accepted if defectives ≤ acceptance number (from Table 2, col 3).

Summary:

• Sample size and acceptance numbers increase with lot size.
• Zero acceptance number means no defectives allowed.
• Larger lots allow some defectives but limited by acceptance number.

flowchart TD
    A[Lot Size] --> B{Select Table}
    B -->|Clause 5.1.1| C[Use Table 1]
    B -->|Clause 5.1.2| D[Use Table 2]
    C --> E[Sample Size & Acceptance No.]
    D --> E
    E --> F{Defectives in Sample ≤ Acceptance No.?}
    F -->|Yes| G[Accept Lot]
    F -->|No| H[Reject Lot]

This

IS 9140: Test Frequencies and Sampling Scales

Key Tables for Sampling and Acceptance

Table 1: Sampling for Non-destructive Tests (Clause 5.1.1)

Table 2: Sampling for Warpage, Dimensional, Construction, Flushing, and Cleanability Tests (Clause 5.1.2)

Notes:

• Sampling scales are based on IS 2500 (Part 1): 1992, which uses Attribute Sampling Plans indexed by Acceptance Quality Level (AQL).
• Acceptance Number indicates the maximum number of defective units allowed in the sample for the lot to be accepted.
• If the number of defects exceeds the acceptance number, the entire lot is rejected or subjected to further testing.

flowchart TD
    A[Lot of Appliances] --> B{Lot Size}
    B -->|Up to 90| C[Sample Size: 5, Accept: 0]
    B -->|91 to 150| D[Sample Size: 8, Accept: 0]
    B -->|151 to 500| E[Sample Size: 13, Accept: 0]
    B -->|501 to 1200| F[Sample Size: 20, Accept: 1]
    C & D & E & F --> G{

IS 9140: List of Referenced Indian Standards (Annex A)

This annex provides the key Indian Standards referenced for sanitary appliances and water fittings, essential for quality control and specification compliance.

Key Referenced IS Standards Summary:

Important Notes:

• Clause 5.2.3: A lot conforms if all destructive tests meet the relevant specifications.
• These standards cover quality control, material specifications, and specific appliance requirements such as water closets, urinals, sinks, bidets, and accessories.
• Statistical methods (IS 397) ensure production quality using control charts.
• Sampling methods (IS 4905) guide acceptance testing.

Usage:

• Refer to these IS parts for detailed test methods, acceptance criteria, and product-specific requirements.
• Ensure compliance by following the relevant part for the appliance or test type.

graph LR
A[IS 9140] --> B[IS 397: Statistical Quality Control]
A --> C[IS 2556: Vitreous Sanitary Appliances]
A --> D[IS 4905: Random Sampling]
B --> B1[Control Charts for Variables]
B --> B2[Control Charts for Attributes]
C --> C1[General Requirements]
C --> C2[Water Closets]
C --> C3[Urinals, Sinks, Bidets, Accessories]

This structured referencing ensures standardized quality and performance for sanitary appliances in India.

IS 9140 - Committee Composition & Key Specifications

Committee Composition (Annex B - Foreword)
The Sanitary Appliances and Water Fittings Sectional Committee, CED 3, includes representatives from:

• Delhi Water Supply and Sewage Disposal Undertaking (Chairman: Shri S. Prakash)
• Central Public Health and Environmental Engineering (Adviser PHE)
• Industry representatives (e.g., Goverdhan Das P.A., E.I.D. Parry Ltd.)
• Research institutes (CSIR, Central Glass and Ceramic Research Institute)
• Government departments (Ministry of Defence, Railways, Public Works)
• Manufacturers and testing agencies (Hindustan Sanitaryware, National Test House)

Sampling & Acceptance Criteria for Tests (Clauses 5.1.1, 5.1.2, 5.2.3)

Conformance Criterion (Clause 5.2.3)

• A lot conforms if all relevant tests meet the acceptance criteria.

Summary

• The committee comprises multidisciplinary experts from government, industry, and research.
• Sampling sizes and acceptance numbers vary with lot size and test type.
• Zero or minimal defective