Fabricated PVC-U fittings for Potable Water Supplies, Part 8: Specific Requirements for 90-degree Bends

IS 10124 Part 8: Scope & Key Specifications for 90° Bends

Scope Summary:

• Applies to dimensions and wall thickness of 90° bends in ductile iron pipes.
• Covers bends with plain ends and elastomeric sealing ring joints.
• Dimensions and thicknesses ensure suitability for different working pressures (0.4 to 1.25 MPa).

Key Dimensions (from Table 1 & Fig. 1):

• Y = Distance from end to center of bend.
• L = Length of plain end (if applicable).
• R = Radius of bend curvature.

Notes:

• Wall thickness varies with working pressure class (Class 2 to Class 5).
• For elastomeric sealing ring joints, refer to Table 2 and Fig. 2 (not shown here).
• Rounding off of dimensions should follow IS 2:1960 rules.

IS 10124 Part 8: Key Formulas, Tables & Specifications for 90° Bends

References:

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

Important Dimensions & Thickness (Tables 1 & 2):

Wall Thickness Calculation:

• Minimum wall thickness t = 90% of the minimum wall thickness of corresponding pipe size & pressure class, rounded up to next 0.1 mm.

Example from Table 1 (90° Bend with Plain Ends):

Example from Table 2 (90° Bend for Elastomeric Sealing Ring Joint):

IS 10124 Part 8: Manufacture Key Details

Clause 3.2: Manufacture

• Defines manufacturing requirements for 90° bends in pipes, including dimensions and wall thickness.

Key Tables for 90° Bends (Clause 3.2.2)

• R (Min radius) = 3 × Nominal Outside Diameter (D)
• Y (Min) = Calculated from 90° × 2πR / 360°

Table for 90° Bend with Elastomeric Sealing Ring Joint

IS 10124 Part 8: Marking of 90° Bends

Marking Requirements (Clause 4.1)

Each 90° bend must be indelibly marked with:

• Manufacturer's name/ID
• Size of bend and class (working pressure) per IS 4985
• Degree of bend (90°)
• Colour code for class:

BIS Certification Mark (Clause 4.2)

• Optional Standard Mark per BIS Act 1986.

Key Dimensions & Minimum Wall Thickness (Table 1 Excerpt)

• R = 3 × Nominal Outside Diameter (D)
• Y = (90° × 2 × π × R) / 360°

Summary:

• Mark bends with manufacturer, size, class, degree, and color.
• Use wall thickness from tables based on size and pressure class.
• Optional BIS mark for quality assurance.

For detailed dimensions and thicknesses, refer to IS 10124 Part 8 Table 1 and 2.

IS 10124 Part 8 (2009) — Key Dimensions for 90° Bends

1. Dimensions of 90° Bends (Table 1 & Fig. 1)

• Radius (R) = 3 × Nominal Outside Diameter (D)
• Y (Min) = (90° × 2 × π × R) / 360° = π × R / 2 (arc length for 90° bend)
• L (Min): Minimum length for plain ends (varies by size)
• Minimum Wall Thickness (t) depends on working pressure class (MPa) from 0.4 to 1.25

(Refer to the full Table 1 for all sizes and thicknesses)

2. Dimensions for 90° Bends with Elastomeric Sealing Ring Joint (Table 2 & Fig. 2)

• Similar parameters: Y, L, R, and wall thickness t for various pressure classes.
• Wall thickness generally higher due to sealing requirements.

IS 10124 Part 8 (2009) - Material Requirements: Key Specifications

1. Material & General Requirements

• Refer to IS 10124 Part 1 for material types, sizes, tests, sampling, and conformity criteria.
• Materials must comply with BIS certification and quality standards.

2. Caps & Fittings

• Specific requirements for caps are detailed in the standard (not provided here).
• Use of Standard Mark governed by BIS Act, 1986 (Clause 4.2.1).

3. Dimensions & Wall Thickness for 90° Bends (Table 1, Clause 3.2.2)

IS 10124 (Part 8): Pressure Classes & Wall Thickness for 90° PVC Bends

Pressure Classes (Working Pressure in MPa)

• Class 2: 0.4 MPa (Blue)
• Class 3: 0.6 MPa (Green)
• Class 4: 0.8 MPa (Brown)
• Class 5: 1.0 MPa (Yellow)
• Class 6: 1.25 MPa (Black)
• Plumbing: Special class (Pink)

Key Specifications:

• Minimum Wall Thickness (t) varies with nominal size and pressure class.
• Radius of bend R = 3 × Nominal Outside Diameter (D)
• Dimension Y is calculated as:
  [ Y = \frac{90^\circ \times 2 \pi R}{360^\circ} = \frac{\pi R}{2} ]
• Minimum wall thickness is 90% of the corresponding pipe thickness, rounded to next 0.1 mm.

Example Table Extract (Plain Ends):

Notes:

• Wall thickness increases with pressure class and size.
• Marking color codes ensure easy identification of pressure class.
• Elastomeric sealing ring joints have separate thickness tables (see Table 2 in the standard).

flowchart LR
    A[Nominal Size (D)] --> B[Radius R = 3 × D]
    B --> C[Y = (π × R) / 2]
    C --> D[Determine Wall Thickness t based on Pressure Class]
    D --> E[Mark fitting with class color and size]

For full tables and detailed dimensions, refer to Tables 1 & 2 of IS 10124 (Part 8): 2009.

IS 10124 Part 8: Types of Ends for 90° Bends (Plain and Socketed)

Key Points:

• Ends Types:

  • Plain Ends: Both ends are plain.
  • Socketed Ends: Socketed at one or both ends as agreed. Socket dimensions follow IS 10124 Part 1.

• Material Note:

  • For 0.25 MPa pressure class, bends must be made from 0.4 MPa pipes, not 0.25 MPa pipes.

Dimensions & Wall Thickness (from Table 1):

• Y = Min length for plain ends
• L = Min length for socketed ends
• R = Radius of bend

Summary Diagram:

graph LR
A[Pipe] --> B{End Type}
B --> C[Plain End]
B --> D[Socketed

IS 10124 Part 8: Elastomeric Sealing Ring Joints for 90° Bends

Key Specifications:

• Minimum Bend Radius (Rmin): 3 × Nominal Outside Diameter (D)
• Ymin (Dimension Y): Calculated as ( Y = \frac{90^\circ \times 2 \pi R}{360^\circ} = \frac{\pi R}{2} )
• Minimum Wall Thickness (t): Based on 90% of pipe's minimum wall thickness, rounded up to next 0.1 mm.

Table 2: Dimensions of 90° Bend for Elastomeric Sealing Ring Joint

(Refer to IS 10124 Part 8 Table 2 for full sizes)

Notes:

• Dimensions Y and R relate to bend geometry ensuring proper sealing and flow.
• Wall thickness varies with pressure class (0.4 to 1.25 MPa).
• Elastomeric sealing ring joints require these dimensions for compatibility and performance.

flowchart LR

IS 10124 Part 8: Testing and Conformity Criteria - Key Points

1. General Requirements

   • Refer to IS 10124 Part 1 for material, size, testing methods, sampling, and conformity criteria.
   • Compliance is based on final test values rounded per IS 2:1960 rules.

2. Rounding Off Values

   • Round test results to the same number of significant digits as specified in the standard.
   • Example: If specified value is 12.5 (3 significant digits), round test results similarly.

3. Testing & Sampling

   • Sampling procedures and test methods align with Part 1.
   • Tests include mechanical, chemical, and dimensional checks as per IS 10124 (Part 1).

4. Caps Specifics

   • Caps have additional specific requirements (refer to Part 8 detailed clauses).

Rounding Rule (IS 2:1960) Summary:

Compliance Check Flow

flowchart TD
    A[Sample Collection] --> B[Test Conducted (per IS 10124 Part 1)]
    B --> C[Results Obtained]
    C --> D[Round Values (IS 2:1960)]
    D --> E{Conforms to Specified Limits?}
    E -->|Yes| F[Accept Batch]
    E -->|No| G[Reject Batch]

For detailed formulas and tables, refer to IS 10124 Part 1 as Part 8 defers to it for testing and conformity criteria.

IS 10124 Part 8: Certification and BIS Marking Key Points

1. Certification Marking (Clause 4.2)

• Pipes/bends may carry the BIS Standard Mark.
• Use governed by the Bureau of Indian Standards Act, 1986.
• License for use granted by BIS under specified conditions.

2. Minimum Wall Thickness Calculation (Clause 1.25)

• Minimum wall thickness, ( t_{min} ), = 90% of the standard minimum wall thickness for size & pressure class, rounded up to next 0.1 mm.
• Bend radius ( R_{min} = 3 \times D ) (nominal outside diameter).
• Y (min) for 90° bend = ( \frac{90^\circ \times 2\pi R}{360^\circ} = \pi R / 2 ).

3. Key Table Extract: Minimum Wall Thickness (t) for 90° Bends

(Refer to full tables in IS 10124 Part 8 for all sizes and pressures)

Summary Diagram: Bend Dimensions

flowchart LR
    A[Nominal Diameter D]
    B[Bend Radius R = 3D]
    C[Y = πR/2 (Length of bend arc)]
    D[Minimum Wall Thickness t = 0.9 × standard thickness]
    A --> B --> C --> D

**For detailed dimensions, working pressures, and licensing conditions, refer to IS 10124 (Part 8): 2009 Clause 1.25, 4.2

IS 10124 (Part 8): Key Formulas, Tables & Specifications for Annexures and Figures

Important Formulas:

• Minimum Wall Thickness (t):
  ( t_{min} = \text{round up to next 0.1 mm} \left(0.9 \times t_{pipe}\right) )
  where ( t_{pipe} ) = minimum wall thickness of corresponding pipe size & pressure class.

• Minimum Bend Radius (R):
  ( R_{min} = 3 \times D )
  where ( D ) = nominal outside diameter.

• Dimension Y (Min):
  ( Y_{min} = \frac{90^\circ \times 2 \pi R}{360^\circ} = \frac{\pi R}{2} )

Tables Summary:

Example from Table 1 (90° Bend, Nominal Size 110 mm):

Notes:

• Dimensions are in millimeters.
• Wall thickness values correspond to working pressure classes (0.4, 0.6, 0.8, 1.0, 1.25 MPa).
• Drawings (Fig.1 & Fig.2) define terms but not detailed design features.
• Rounding off per IS 2:1960 rules.

flowchart LR
  A[Nominal Outside Diameter (D)] --> B[Calculate R_min = 3 × D]
  B --> C[Calculate Y_min = (π × R_min) / 2]
  D[