washers for use with fittings for water services

IS 4346: Scope & Key Specifications for Washers

Scope (Clause 2.0)

• Defines terms related to washers used in taps and valves.
• Covers materials like vulcanized natural rubber, vegetable tanned hydraulic leather, and high-density polyethylene.

Key Dimensions (Clause 6.1, Table 1)

• *Internal diameter tolerance: +0.5 mm
• Thickness variation for leather washers: ±5%

Material Requirements (Clause 3.2)

• Washer materials must not corrode metal seating or washer plate to ensure longevity of taps/valves.

Summary:

• Washers are standardized by thickness and diameter per nominal size.
• Materials include rubber, leather, and polyethylene with corrosion resistance.
• Dimensions ensure compatibility and performance in tap and valve assemblies.

flowchart LR
    A[Nominal Size] --> B[Thickness (Min)]
    A --> C[Internal Diameter (+0.5 mm tolerance)]
    A --> D[External Diameter (Min-Max)]
    E[Materials] --> F[Vulcanized Rubber]
    E --> G[Hyd

IS 4346: Key Definitions, Dimensions & Specifications for Washers

Definitions (Clause 2.0)

• Defines terms related to washers used in taps and valves.
• Ensures uniform understanding of materials, dimensions, and performance criteria.

Dimensions of Washers (Clause 6.1, Table 1)

*Internal diameter tolerance: +0.5 mm.

Material Specifications & Performance (Clauses 1.10, 3.2)

• Density: Minimum 1.10 g/cm³.
• Shear Strength: Minimum 55 MPa.
• Washer material must not corrode metal seating or washer plate, ensuring durability of taps/valves.

Notes:

• Thickness variation for leather washers: ±5%.
• Materials include vulcanized natural rubber, vegetable tanned hydraulic leather, and high-density polyethylene.

flowchart TD
    A[Washer] --> B[Dimensions]
    B --> C[Thickness]
    B --> D[Internal Diameter]
    B --> E[External Diameter]
    A --> F[Material Properties]
    F --> G[Density

IS 4346 – Effects on Potable Water and Metals: Key Points

1. Effect on Potable Water (Clause 3.1)

• No taste or toxic effect: Tap washer materials must not impart taste or toxicity.
• Residual chloride limit: ≤ 0.2 mg/l in water.
• No color imparted: After 24 hours immersion in 250 ml potable water at 10°C and 45°C (second exposure).
• No bacterial growth fostered by materials.

2. Effect on Metal (Clause 3.2)

• Washer material must not corrode metal seating or washer plate.
• Corrosion should not impair the performance or lifespan of taps/valves.

Additional Specifications Referenced:

• Cast copper alloy bib taps, stop valves, pillar taps, self-closing taps, ferrules, marine taps, fancy bib & pillar taps, flush valves.

Summary Table: Water Exposure Test for Washer Material

flowchart LR
    A[Washer Material] --> B{Test in Potable Water}
    B -->|No taste| C[Pass]
    B -->|No toxicity| C
    B -->|No color after 24h at 10°C & 45°C| C
    C --> D{Effect on Metal}
    D -->|No corrosion| E[Pass]
    D -->|No impairment of tap life| E

This ensures safe, durable, and hygienic water fittings per IS 4346.

IS 4346: Key Material Specifications for Washers

1. Material Types (Clause 4.1)

• Vegetable tanned hydraulic leather
• High-density polyethylene (HDPE)
• Vulcanized fibre

2. Material Properties

3. Washer Dimensions (Clause 6.1, Table 1)

Note: Thickness tolerance for leather washers ±5%; internal diameter tolerance +0.5 mm.

Summary:

• Use vegetable tanned leather, HDPE, or vulcanized fibre.
• Maintain density ≥ 1.10 g/cm³ and **shear/tensile

IS 4346: Key Requirements for Washers

1. Dimensions (Clause 6.1, Table 1)

• Thickness variation for leather washers shall not exceed ±5%.

2. Material Specifications (Clause 4.1)

• Vegetable tanned hydraulic leather
• High-density polyethylene (HDPE)
• Vulcanized fibre
• Vulcanized natural rubber compounds (per first revision)
• Vegetable tanned hydraulic leather (second revision)

3. Mechanical Properties (Clause 1.10)

• Density: Minimum 1.10 g/cm³
• Shear Strength: Minimum 55 MPa

Summary:

• Washers must conform to dimensional tolerances in Table 1.
• Material choice is limited to specified types ensuring durability.
• Mechanical properties ensure performance under load.

flowchart TD
    A[Washer Requirements] --> B[

IS 4346: Dimensions of Washers for Water Service Fittings

Key Specifications (Clause 6.1 & Table 1)

• Thickness and Diameter of washers are standardized as follows (all dimensions in mm):

• Tolerance: Internal diameter tolerance of +0.5 mm permitted.
• Thickness variation: For leather washers, ±5% thickness variation allowed.

Notes:

• Thickness is the minimum value.
• Dimensions ensure compatibility with standard taps and valves.
• Materials include vulcanized rubber, vegetable tanned leather, and high-density polyethylene.

This table guides washer manufacture and quality control for water service fittings per IS 4346.

IS 4346: Marking Specifications (Clause 7.1 & 7.2)

• Marking on Boxes/Cartons:

  • Must include the manufacturer's identification mark and trade-mark (Clause 7.1).
  • May include the ISI Certification Mark if licensed (Clause 7.2).

• ISI Certification Mark:

  • Indicates compliance with IS standards.
  • Governed by Indian Standards Institution (Certification Marks) Act.
  • Ensures product quality via inspection, testing, and continuous surveillance.

Key Dimensions for Washers (Table 1, Clause 6.1)

• Thickness tolerance for leather washers: ±5%
• Internal diameter tolerance: +0.5 mm permitted

Summary Diagram: Marking Flow

flowchart TD
    A[Washer Boxes/Cartons] --> B[Mark Manufacturer ID & Trade Mark]
    B --> C{ISI Certification Mark?}
    C -- Yes --> D[Apply ISI Mark as per ISI Act]
    C -- No --> E[No ISI Mark

IS 4346: Packaging and Identification Key Points

• Clause 7.1:
  The manufacturer's identification mark and trade-mark must be clearly marked on the box/carton containing washers.

• Clause 7.2 (Marking Table):
  Boxes/cartons may also carry the ISI Certification Mark indicating compliance with Indian Standards under ISI's inspection and quality control.

• ISI Certification Mark:

  • Indicates product conformity to IS standards.
  • Usage governed by Indian Standards Institution (Certification Marks) Act.
  • Ensures continuous quality checks by ISI.

• Packaging Material:
  High-density polyethylene used should comply with IS 7328-1974 (Clause 5.4).

Summary Table: Packaging Markings

Notes:

• Proper marking aids traceability and quality assurance.
• Packaging must protect washers and maintain identification integrity during transport.

flowchart TD
    A[Washer Packaging] --> B[Manufacturer's Mark]
    A --> C[Trade-Mark]
    A --> D[ISI Certification Mark (optional)]
    D --> E[Compliance with IS Standards]
    E --> F[Quality Control & Inspection]

This ensures traceability, quality, and compliance per IS 4346.