Fabricated PVC-U Fittings for Potable Water Supplies - Specification, Part 3: Specific Requirements for Straight Reducers

IS 10124 (Part 3) : 2009 — Scope Key Specifications & Formulas

Scope:
Covers dimensions and minimum wall thickness of straight reducers used in ductile iron pipes, ensuring compatibility and pressure class compliance.

Key Dimensions & Symbols:

Important Table: Dimensions & Wall Thickness of Straight Reducers (excerpt)

*Refer to full Table 1 in IS 10124 Part 3 for

IS 10124 (Part 3): Key References, Formulas & Tables

References (Table 2)

• IS 4985: 2000 — Unplasticized PVC pipes for potable water supplies.
• IS 10124 (Part 1): 2009 — Fabricated PVC-U fittings for potable water supplies (General requirements).

Key Dimensions & Terms (Fig.1 & Clauses)

• D = Mean socket internal diameter (mid-point of socket length).
• d = Mean outside diameter of spigot (pipe used for reducer).
• L = Minimum socket length (per IS 10124 Part 1).
• C = Minimum spigot length = 0.5 × d_nom + 10 mm.
• T = Min wall thickness of spigot (same nominal size & pressure class).
• t = Min wall thickness of socket = 90% of T, rounded up to next 0.1 mm.

Table 1: Dimensions & Wall Thickness of Straight Reducers (mm)

IS 10124 Part 3: General Requirements Summary

• Materials, Sizes, Tests, Sampling, and Conformity:
  Refer to IS 10124 (Part 1) for detailed specifications on these aspects. Part 3 does not repeat but mandates compliance with Part 1.

• Key Reference Standards:

  IS No.	Title
  IS 4985 : 2000	Unplasticized PVC pipes for potable water supplies
  IS 10124 (Part 1):2009	Fabricated PVC-U fittings for potable water supplies - General requirements

• Implication:
  For design and quality control, use IS 10124 Part 1 as the baseline for material properties, dimensional tolerances, testing methods, and acceptance criteria.

Typical General Requirements (from IS 10124 Part 1):

• Material: Rigid PVC-U, complying with IS 4985.
• Dimensions: As per standard pipe sizes with specified tolerances.
• Tests:
  • Hydrostatic pressure test
  • Dimensional checks
  • Impact resistance
  • Visual inspection
• Sampling: Random sampling per batch for conformity testing.

flowchart LR
    A[Raw Material] --> B[Fabrication]
    B --> C[Dimensional Checks]
    C --> D[Hydrostatic Test]
    D --> E[Sampling & Inspection]
    E --> F{Conformity?}
    F -- Yes --> G[Approved for Use]
    F -- No --> H[Reject/Retest]

Use IS 10124 Part 1 as the primary guide for all general requirements in Part 3.

IS 10124 Part 3 (2009) — Materials Key Points

Material Specifications

• Materials, sizes, tests, sampling, and conformity criteria conform to IS 10124 (Part 1).
• Use of BIS Standard Mark governed by Bureau of Indian Standards Act, 1986.

Key Dimensions & Terms (Fig. 1 & Table 1)

Wall Thickness for Working Pressure (MPa) — Selected Values from Table 1

Notes

• Wall thickness varies with pressure class (0.4 to 1.25 MPa).
• Dimensions and thicknesses ensure mechanical strength and pressure resistance.
• Rounding off per IS 2:1960 rules.

Summary Formula for Spigot Length (C):

[ C = 0.5 \times d_{nom} +

IS 10124 Part 3 (2009) — Manufacture of Straight Reducers: Key Formulas & Specifications

Key Dimensions & Definitions (Clause 3.2)

Wall Thickness & Dimensions for Straight Reducers (Excerpt from Table 1)

Straight Reducer - IS 10124 Part 3 (2009) Key Details

1. Illustration & Dimensions (Clause 3.2.1 & 3.2.2)

• Fig. 1 defines terms for straight reducer dimensions.
• Dimensions must comply with Table 1.
• Key parameters:
  • D: Mean socket internal diameter (mid-point of socket length)
  • d: Mean outside diameter of spigot (pipe end)
  • L: Minimum socket length (per IS 10124 Part 1)
  • C: Minimum spigot length = 0.5 × d_nom + 10 mm
  • T: Minimum wall thickness of spigot (pipe thickness)
  • t: Minimum wall thickness of socket = 90% of spigot thickness, rounded up to 0.1 mm

2. Dimensions Table (Excerpt from Table 1)

Refer full Table 1 for all sizes and pressure classes.

3. Marking (Clause 4.1)

• Markings must include:
  • Manufacturer’s name/ID
  • Size and class (pressure rating per IS 4985)
  • Colour code for pressure class:

IS 10124 Part 3: Dimensions of Straight Reducers

Key Dimensions & Definitions (Clause 3.2.2 & Fig.1)

• D: Mean socket internal diameter at mid-length (from IS 10124 Part 1)
• d: Mean outside diameter of spigot (pipe end)
• L: Minimum socket length (IS 10124 Part 1)
• C: Minimum spigot length = 0.5 × d_nom + 10 mm
• T: Minimum wall thickness of spigot (based on pipe size and pressure class)
• t: Minimum wall thickness of socket = 90% of spigot thickness, rounded up to 0.1 mm

Table 1: Dimensions of Straight Reducers (Sample Extract)

Note: Full table covers sizes 20 to 355 mm and pressure classes 0.4 to 1.25 MPa.

Important Formulas

• Spigot Length, C:
  [ C = 0.5 \times d_{nom} + 10 \text{ mm} ]

• Socket Wall Thickness, t:
  [ t = \text{round up}\left(0.9 \times T, 0.1 \text{ mm}\right) ]

Summary

• Reducer dimensions are standardized for socket and

IS 10124 Part 3: Marking of Straight Reducers

Key Marking Requirements (Clause 4.1)

Each straight reducer must be clearly marked with:

• Manufacturer's name or ID
• Reducer size and class (working pressure per IS 4985)
• Colour coding by class:

BIS Certification Marking (Clause 4.2)

• Reducers may carry the BIS Standard Mark per BIS Act 1986.
• Use of the Standard Mark requires a license from BIS.

Dimensions & Thickness (Table 1 Summary)

• D = mean socket internal diameter
• d = mean outside diameter of spigot
• L = minimum socket length
• C = minimum spigot length = 0.5 × d_nom + 10 mm
• T = min wall thickness of spigot (per pressure class)
• t = min wall thickness of socket = 90% of spigot thickness rounded up

Example for 50-40 reducer (Class 4, 0.8 MPa):

• D = 40.3 mm, d = 40 mm, L = 15 mm, C = 30 mm
• T (spigot) = 1.8 mm
• t (socket) = 1.6 mm

Summary Table Extract (Wall Thickness t in mm)

IS 10124 Part 3 — Marking Details for Straight Reducers

Key Marking Requirements (Clause 4.1)

Each reducer must be clearly and indelibly marked with:

• Manufacturer's name or ID mark
• Reducer size and corresponding IS 4985 class (working pressure)
• Colour code by class:

BIS Certification (Clause 4.2)

• Optional Standard Mark as per BIS Act, 1986.

Dimensions & Wall Thickness (Table 1 Summary)

BIS Certification Marking (IS 10124 Part 3 - Clause 4.2)

• Each straight reducer can be marked with the BIS Standard Mark indicating compliance.
• BIS is a statutory body under the Bureau of Indian Standards Act, 1986, responsible for standardization, marking, and quality certification in India.

Key Specification: Minimum Wall Thickness (t) for Reducers

Note: For pressure class 0.25 MPa, reducers should be made from 0.4 MPa class pipes, not 0.25 MPa pipes.

BIS Marking Guidelines:

• Marking should include the Standard Mark.
• Ensures product quality and conformity to IS 10124 (Part 3): 2009.
• Reproduction of BIS publications requires permission, but use of symbols and sizes for implementation is free.

Contact & Reference:

• BIS Headquarters: Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002
• Website: www.bis.org.in

flowchart TD
    A[Reducer] --> B[BIS Certification Mark]
    B --> C[Compliance with IS 10124 Part 3]
    C --> D[Minimum Wall Thickness as per Pressure Class]
    D --> E[Quality Assurance & Standardization]

This ensures traceability and quality adherence for pipe reducers under BIS standards.

Sampling and Criteria for Conformity as per IS 10124 (Part 3) refers to the general provisions laid down in IS 10124 (Part 1).

Key Points:

• Sampling: Follow the sampling procedure detailed in IS 10124 (Part 1), which includes selecting representative samples from production batches for testing.

• Criteria for Conformity:

  • Test results must meet specified limits in the standard.
  • Final test values are rounded off according to IS 2:1960 rules.
  • The number of significant digits in the rounded value must match the specified value.

Rounding Off (IS 2:1960):

Reference Standards:

Summary Diagram:

flowchart TD
    A[Batch of PVC-U fittings] --> B[Sampling as per IS 10124 (Part 1)]
    B --> C[Test samples]
    C --> D{Test results within limits?}
    D -- Yes --> E[Conformity confirmed]
    D -- No --> F[Reject batch or reprocess]
    E --> G[Rounding off as per IS 2:1960]

For detailed sampling sizes, acceptance criteria, and test methods, refer to IS 10124 (Part 1).

IS 10124 Part 3: Typical Dimensions of Straight Reducers

Key Definitions (Clause 3.2.2 & Fig.1)

• D: Mean socket internal diameter at mid-point (IS 10124 Part 1)
• d: Mean outside diameter of spigot (pipe outside diameter)
• L: Minimum socket length (IS 10124 Part 1)
• C: Minimum spigot length = 0.5 × d_nom + 10 mm
• T: Minimum wall thickness of spigot (same as pipe thickness for nominal size & pressure class)
• t: Minimum wall thickness of socket = 90% of spigot thickness (rounded up to 0.1 mm)

Typical Dimensions Table (Excerpt)