Polyethene Fittings for use with Polyethylene Pipes for the supply of Gaseous Fuels - Specification, Part 2: Spigot Fittings for Butt Fusion for Socket Fusion using Heated Tools and for use with Electro Fusion Fittings

IS 15927 Part 2: Scope & Key Specifications Summary

Scope (Clause 5.5):

• Covers buried polyethylene spigot fittings joined by heated tools fusion.
• For polyethylene pipes per IS 14885:2001 and fittings per IS 15927 Parts 1 & 3 (2012).
• Applicable for nominal outside diameters 16 mm to 630 mm, SDR 11 and SDR 17.6.
• Material grades: PE 80 and PE 100.
• Pressure rating: up to 5.5 bar (note: 1 bar = 0.1 MPa) and 7 bar.
• Operating temperature: -5°C to 40°C.

Key Tables & Values

1. Spigot Length Minimum (mm) — Clause 8.2

2. Out-of-Square Values for Fitting Ends (mm) — Clause 8.3.3

3. Lot Definition & Sampling (Clause 10.1)

• Lot size: Max 170 hours or 10,000 fittings.
• Break >8h or raw material change ends a lot.
• Sampling plans for quality tests per Tables 6, 7, 8.

4. Sampling for Visual & Dimensional Tests (Table 7)

| Lot Size (No. of fittings) | First Sample Size | Acceptance No. | Rejection No. | |----------------------------

Here are the key formulas, tables, and specifications from IS 15927 Part 2:2012 related to pipe fittings:

1. Nominal Diameter & Mean Outside Diameter (Clause 8.2.1, Table 1)

• Grade A Tolerance: 0.009 × d (min 0.3 mm, max 10 mm)
• Grade B Tolerance: 0.006 × d (min 0.3 mm, max 4 mm)

2. Spigot Length Minimum (Clause 8.2, Table 2A)

3. Out-of-Square Values for Fitting Ends (Clause 8.3.3, Table 3)

IS 15927 Part 2: Key Definitions, Formulas & Tables

1. Definitions

• Out of Square (Clause 3.21):
  Deviation of the perpendicularity of the fitting end plane relative to the fitting's longitudinal axis.

2. Nominal Diameter & Dimensions (Clause 8.2.1 & Table 1)

• Nominal diameters: 16 mm to 630 mm.
• Tolerances on mean outside diameter:
  • Grade A: ±0.009d (min 0.3 mm, max 10 mm)
  • Grade B: ±0.006d (min 0.3 mm, max 4 mm)

(Refer to full Table 1 in IS 15927 Part 2 for all sizes)

3. Out-of-Square Values for Fitting Ends (Clause 8.3.3, Table 3)

4

IS 15927 (Part 2) - Key Material Specifications & Tables

1. Grade of Material (Clause 5.2)

• Material grades must conform to specified polymer standards for PE 80 and PE 100.
• Raw material properties should match manufacturer's specifications.

2. Melt Flow Rate (MFR) (Clause 9.3)

• Tested as per IS 2530 at 190°C, with 5 kgf load.
• MFR of fittings' material should not deviate more than ±30% from raw material values.
• MFR change due to processing must be monitored to ensure quality.

3. Hydraulic Pressure Test Characteristics (Table 4, Clause 9.2)

4. Test Piece Dimensions (Clause 3.2.2)

• Type A Test Piece for tensile testing (E < 25 mm) per Fig. 3 & Table 11.
• Type B Test Piece for E > 25 mm per Fig. 4.

5. Typical Fitting Dimensions (Clause 8.2, Table 8.2.1)

Summary Diagram: Hydraulic Test Setup

flowchart LR
    A[Pipe Sample] --> B[Conditioning (1-12 h)]
    B --> C[Hydraulic

IS 15927 Part 2 - General Requirements Summary

1. Out-of-Square Values of Fitting Ends (Clause 8.3.3, Table 3)

2. Typical Spigot Lengths for Fittings (Clause 8.2, Table 8.2.1)

3. Hydraulic Pressure Test Characteristics (Clause 9.2, Table 4)

4. Melt Flow Rate (Clause 9.3)

• Tested as per IS 2530 at 190°C with 5 kgf load.
• MFR variation from raw material ≤ 30% (composite sample of 3 fittings

IS 15927 (Part 2) - Material Properties Key Points

1. Grade of Material (Clause 5.2)

• Specifies the material grade used for fittings and pipes.

2. Melt Flow Rate (MFR) (Clause 9.3 & 5.5)

• Tested as per IS 2530 at 190℃ with 5 kgf load.
• MFR of fittings should not differ by more than ±30% from raw material values.
• Change in MFR due to processing should be ≤ 25%.

3. Minimum Required Strength (MRS) (Clause 3.14)

• MRS is the minimum long-term hydrostatic strength in MPa for the material.

4. Hydraulic Pressure Test Characteristics (Table 4, Clause 9.2)

5. Hydrostatic Strength at 80°C (Table 5)

IS 15927 Part 2: Design & Construction Key Data

1. Nominal Diameter & Dimensions (Clause 8.2.1, Table 1)

Fittings cover 16 mm to 630 mm nominal diameters.

2. Spigot Lengths for Fittings (Clause 8.2, Table 8.2.1)

Applies to caps, reducers, 45° elbows, tees.

3. Out-of-Square Values for Fitting Ends (Clause 8.3.3, Table 3)

IS 15927 Part 2: Geometrical Characteristics Key Data

1. Nominal Diameter & Tolerances (Clause 8.2.1)

• Nominal diameters covered: 16 mm to 630 mm
• Tolerances on mean outside diameters:
  • Grade A: 0.009 × d, rounded to nearest 0.1 mm (min 0.3 mm, max 10 mm)
  • Grade B: 0.006 × d, rounded to nearest 0.1 mm (min 0.3 mm, max 4 mm)

2. Key Dimensions Table (Excerpt)

3. Spigot Lengths for Fittings (Clause 8.2)

4. Definitions

• Out of Square (Clause 3.21): Deviation of the fitting end plane perpendicularity relative to the fitting's

IS 15927 Part 2: Mechanical Properties & Testing Key Points

1. Tensile Test Pieces (Clause 3.2.2)

• Type A Test Piece: For thickness E < 25 mm, dimensions per Fig. 3 and Table 11.
• Type B Test Piece: For thickness E > 25 mm, per Fig. 4.

2. Tensile Testing Machine (Clause 2.1)

• Elongation capacity: 25%
• Test speed: 5 ± 1 mm/min
• Equipped with force recording & failure detection.

3. Melt Flow Rate (MFR) (Clause 9.3)

• Tested per IS 2530 at 190℃, 5 kgf load.
• MFR variation between raw material and fittings ≤ 30%.
• Processing change in MFR ≤ 25%.

4. Hydraulic Pressure Test (Table 4, Clause 9.2)

5. Hydrostatic Strength (80℃) - Stress/Failure Time (Table 5)

IS 15927 Part 2: Acceptance Tests Summary

1. Acceptance Test Conditions (Clause 12.4):

• Test temperature: 80°C for hydrostatic resistance (165 h)
• Conditioning: Water-in-water
• Pressure: Calculated to produce specified circumferential (hoop) stress
• End caps orientation: Not applicable

2. Lot Definition & Sampling (Clause 10.1):

• Lot = production from start to machine shutdown or max 170h/10,000 fittings
• Break >8h or raw material change = new lot
• Sampling per Tables 6, 7 & 8

3. Key Tables for Acceptance Testing:

4. Sampling Plan for Visual & Dimensional (Table 7):

• If defective

IS 15927 Part 2 — Type Tests Summary

1. Purpose (Clause 11.1)

• Type tests validate new raw materials, manufacturing methods, or new fitting sizes.
• Samples prepared per Annex A/B of IS 15927 (Part 1).

2. Type Test Requirements (Clause 11.2 & Table 9)

3. Test Piece Dimensions (Clause 3.2.2 & 5.1)

• Type A test piece (for thickness E < 25 mm):
  Dimensions per Fig. 3 and Table 11
  Width (D) = distance between two holes at joint
  Thickness = pipe wall thickness

• Type B test piece (for E > 25 mm):
  Dimensions per Fig. 4 and Table 11
  Width (D) = narrow portion width

Visual: Type A Test Piece (E < 25 mm)

graph LR
A[Pipe Wall Thickness = t] --> B[Width D = Hole Distance]
B --> C[Type A Tensile Test Piece]

References:

• IS 15927 Part 2:2012 Clauses 11.1, 11.2, 3.2.2, 5.1
• IS 14885 Annex A & H, Clause 5.5

This ensures standardized testing for new materials and fittings to guarantee performance and safety compliance.

IS 15927 Part 2: Marking and Packaging Key Points

Marking (Clauses 12.2, 12.3, 12.4.1)

• Legibility: Marking must be clear and readable without magnification under normal handling, storage, and installation.
• Standard Mark: Use governed by BIS Act 1986; license details available from BIS.
• Marking Info on Outer Pack:
  • Manufacturer details
  • Fitting type
  • Quantity in pack
  • Other info as per Clause 12.2 (a), (b), (c)

Packaging (Clause 12.2)

• Individual Packing: Transparent polyethylene or equivalent bags, minimum 75 microns thickness to prevent deterioration.
• Bulk Packing: Suitable cardboard boxes or cartons for stacked storage.
• Protection: Packaging must protect fittings from damage and environmental effects.

Summary Table for Packaging Requirements

flowchart TD
    A[Fittings] -->|Individually| B[Sealed Polyethylene Bags (≥75μ)]
    A -->|Bulk| C[Cardboard Boxes/Cartons]
    B & C --> D[Outer Pack Marked with Info]
    D --> E[Storage & Transport]

This ensures fittings remain undamaged, identifiable, and compliant with IS 15927 Part 2.

Preparation of Test Assemblies (Butt Fusion) — IS 15927 Part 2 (Annex A)

Key Specifications:

• Pipe for test: IS 14885 compliant; coils for ≤125 mm diameter (type test), straight pipe allowed for acceptance test.
• Fittings dimensions: As per Tables 1, 2, 3 (refer IS 15927 Part 2).
• Conditioning: Pipes & fittings conditioned at 27 ± 2°C for at least 8 hours before fusion.
• Fusion temperature: 210°C to 230°C.
• Assembly spacing:
  • ≥ 375 mm free pipe length between fittings for ≤ 125 mm diameter.
  • ≥ 3 × pipe outside diameter for > 125 mm diameter.
• End closure: Pressure-tight end caps with water inlet and air release.

Tools & Machine Requirements:

• Clamps must secure fittings without damage.
• Maintain roundness and flush clamping.
• Robust machine to withstand fusion pressure without deformation.
• Temperature and pressure cycles per fitting manufacturer or IS 7634 (Part 2).
• Heating element temperature accuracy must be verified before and during fusion.

Fusion Process Notes:

• Prepare joint surfaces immediately before fusion.
• Maintain ambient temperature between +5°C and +45°C for uniform fusion.
• Use machines with controlled pressure application.

Conditioning Before Testing:

• Condition test pieces for minimum 6 hours at 27 ± 2°C.
• Testing to be done not less than 24 hours after fusion.

Summary Table: Assembly Spacing

Fusion Temperature Range

flowchart TD
    A[Start: Select Pipe & Fittings] --> B[Condition at 27 ± 2°C for 8h]
    B --> C[Prepare Joint Surfaces Immediately Before Fusion]
    C --> D[

IS 15927 Part 2: Test Procedures Summary

1. Type Tests (Clause 11.2 & Table 9)

2. Hydrostatic Strength Test @ 80℃ (Clause 5.5 & Table 5)

• Stress vs. Minimum Failure Time (PE 80 & PE 100):

• Note: Only brittle failure counts; if ductile failure occurs earlier, reduce stress and retest.

3. Acceptance Tests (Clause 10.1 & Table 6)

• Tests include visual, dimensional, melt flow rate, density, carbon black content/dispersion, pigment dispersion, thermal stability, hydrostatic resistance at 20℃ & 80℃.
• Sample sizes vary from 7 to 8 depending on the test.
• Reference standards: IS 2530, IS 7328, Annexes of IS 14885.

4. Sampling Plans

• Visual & Dimensional (Table 7): Sample size and acceptance/rejection

IS 15927 (Part 2) — Committee Composition Key Details

The Committee Composition responsible for the formulation of IS 15927 (Part 2) is detailed in Annex E of the standard. It includes representatives from:

• Government bodies (e.g., Central Institute of Plastic Engineering and Technology, Central Public Works Department, Delhi Jal Board)
• Industry leaders (e.g., Chemplast Sanmar Ltd, Finolex Industries, Reliance Industries)
• Municipal and environmental organizations (e.g., Chennai Metropolitan Water Supply, National Environmental Engineering Research Institute)
• Experts in personal capacity and BIS officials

Key Points:

• Chairman: Dr. S. K. Nayak
• Convener (Polyolefins and GRP Piping Subcommittee): Shri Kanwar A. Singh
• Multiple alternate members ensure continuity.
• Involvement of technical experts, engineers, and scientists from diverse sectors ensures comprehensive standard development.

Summary Table of Committee Composition (Excerpt)

If you require specific formulas or tables related to piping dimensions or test procedures, please specify, as Committee Composition mainly lists organizational representation and personnel.