High-density polyethene pipe for sewerage

IS 14333: Scope Key Specifications & Tables

1. Scope Overview

• Covers pipes for chemical industries with various chemical concentrations.
• Concentrations indicated by symbols (Clause 2.2.3):
  • Dil. sol.: ≤10% aqueous solution
  • Sat. sol.: Saturated at 20°C
  • Conc.: Concentrated fluid
  • Work. sol.: Working industrial solution
• Concentrations expressed as % by mass at 20°C unless stated.

2. Pipe Dimensions (Clause 6.1, Table 1)

• Tolerance: Only positive values allowed.
• Ovality: Maximum permissible deviation from circularity.

3. Sampling for Visual & Dimensional Checks (Clause 9.2.3.1, Table 4)

IS 14333 Key References, Tables & Specifications

References (Clause 1.5):

• ISO/TR 10358-1993: Plastics pipes & fittings chemical resistance classification.
• Du Pont 'Sclair' PE resins: Chemical resistance data.
• Mariex (Phillips): Properties of low, medium & high-density polyethylene.

Wall Thickness of PE Pipes (Clause 6.2, Table 2)

Note: Table 7 replaces Table 4 as per Clauses 9.2.3.1 & 9.2.3.3.

Important Formula for Pipe Design (General PE pipe):

[ t = \frac{P \times D}{2 \times (\sigma \times F)} ]

Where:

• (t) = wall thickness (mm)
• (P) = design pressure (MPa)
• (D) = outside diameter (mm)
• (\sigma) = allowable stress of material (MPa)
• (F) = design factor (from IS or ISO standards)

For detailed chemical resistance and mechanical properties, refer to the listed references.

IS 14333 - Key Definitions & Specifications

1. Concentration of Chemicals (Clause 2.2.3)

• Dil. sol.: Dilute aqueous solution ≤ 10% concentration by mass at 20°C.
• Aqueous solution: >10% but not saturated.
• Sat. sol.: Saturated aqueous solution at 20°C.
• Conc.: Concentrated fluid.
• Work. sol.: Working solution used typically in industry.
• Concentrations are expressed by mass % at 20°C, unless otherwise stated.

2. Chemical Characteristics (Clause 2.2.2)

• Melting point (m.p.) and boiling point (b.p.) given in °C.
• Values correspond to technical-grade purity at standard atmospheric pressure.

3. Classification (Clause 2.2.5)

• Chemicals classified based on resistance tables derived from:
  • ISO/TR 10358-1993
  • Du Pont 'Sclair' polyethylene data
  • Phillips Mariex polyethylene properties

Summary Table Example: Concentration Symbols

This framework ensures consistent chemical concentration and property definitions for structural material compatibility and design.

IS 14333 - Material Grades for Pipes

Key Specifications from Clause 3.2 & Table 1

Additional Points:

• Minimum MRS: 6.3 MPa at 20℃ for 50 years (Clause 5.1.1).
• Certification: Manufacturer must provide a conformity certificate for resin MRS.
• Material Grading: Supplied by raw material supplier or pipe manufacturer (Clause 3.2.3).

Definitions:

• MRS (Minimum Required Strength): Long-term strength of the pipe material under sustained load.
• Hydrostatic Design Stress (r): Maximum allowable stress for design at given temperatures.

This table guides selection of pipe grades based on durability and operating temperature conditions.

IS 14333: Material Requirements Summary

1. Material Grades & Strength (Clause 3.2, Table 1)

• MRS minimum: 6.3 MPa at 20℃ for 50 years (Clause 5.1.1)
• Manufacturer’s resin certificate confirming MRS is mandatory.

2. Sampling for Visual & Dimensional Requirements (Clause 9.2.3.1, Table 4)

(Refer to full Table 4 for all lot sizes)

Key Notes:

• MRS defines long-term strength for pipe design.
• Hydrostatic design stress varies with temperature and fluid type.
• Sampling ensures quality control per lot size.
• Obtain manufacturer certification for resin MRS compliance.

flowchart LR
    A[Material Grade] --> B[MRS @ 20℃ (50 yrs)]
    B --> C[Hydrostatic Design Stress]

IS 14333: Dimensions and Tolerances for Pipes

1. Outside Diameter (Clause 6.1 & Table 1)

(Refer full Table 1 in Clause 6.1 for all sizes)

2. Tolerance Formulas (Clause 2.1 & 1.2)

• For DN ≤ 75:
  [ \text{Tolerance} = \max\left(1.2, \text{round up}(0.008 \times DN + 1.0, 0.1)\right) \text{ mm} ]

• For 75 < DN ≤ 250:
  [ \text{Tolerance} = \text{round up}(0.02 \times DN, 0.1) \text{ mm} ]

• For DN > 250:
  [ \text{Tolerance} = \text{round up}(0.035 \times DN, 0.1) \text{ mm} ]

Note: No negative tolerances allowed; minimum tolerance 0.3 mm.

3. Ovality (Clause 6.1)

Ovality is the difference between max and min diameter and should not exceed values in Table 1.

Summary Diagram:

flowchart TD
    A[Nominal Diameter DN] --> B{DN ≤ 75?}
    B -- Yes --> C[Tolerance = max(1.2, round(0.008*DN

IS 14333: Mechanical Properties Summary

1. Material Grades & Mechanical Properties (Clause 3.2.1, Table 1)

• MRS = Minimum Required Strength, must be ≥ 6.3 MPa at 20℃ for 50 years (Clause 5.1.1).

2. Wall Thickness of Pipes (Clause 6.2, Table 2)

• Thickness varies with Nominal Diameter (DN) and Pressure Rating (PN).
• Example for DN 110:

3. Creep Rupture Test Requirements (Clause 9.1.2, Table 3)

Key Formula: Hydrostatic Design Stress (r)

[ r = \text{MRS} \times \text{Design Factor} ]

• Design factors vary with temperature and service type (see Table 1).

IS 14333 - Testing Methods: Key Formulas, Tables & Specs

1. Sampling for Visual & Dimensional Requirements

Table 4: Scale of Sampling (Clause 9.2.3.1)

• Sampling size and acceptance criteria increase with lot size.
• Two-stage sampling is used for quality control.

2. Internal Pressure Creep Rupture Test (Table 3, Clause 9.1.2)

• Used for assessing pipe long-term strength under pressure.

3. Other Tests (Clause 8.3 - 8.5)

• Density, MFR, Carbon Black Content/Dispersion:
  Lot passes if no sample fails.

Summary Diagram: Sampling & Testing Flow

flowchart TD
    A[Start: Pipe Lot] --> B{Lot Size?}
    B -->|Up to 150| C[Sample 13 pipes]
    B -->|151 to 280| D[Sample 20 pipes]
    B -->|>280| E[Sample as per Table 4]
    C --> F{Acceptable defects?}
    D --> F
    E --> F
    F -->|Yes| G

IS 14333: Sampling and Acceptance Criteria (Clause 9.2.3.1 & Table 4)

For visual and dimensional requirements, sampling depends on the lot size as per the table below:

Key Points:

• Sampling is done in two stages: First and Second samples.
• Acceptance Number (Ac): Max allowable defects to accept the lot.
• Rejection Number (Re): Defects count leading to rejection.
• If defects ≤

IS 14333: Marking and Packaging Key Points

Marking Requirements (Clause 10.1 & 10.2)

• Marking Location:
  • On each straight pipe length: both ends
  • On coils: both ends and every meter along the length
• Marking Method:
  • Indelible ink/paint or hot embossing on white base
• Information to Mark:
  • Manufacturer's name or trademark
  • Designation of pipe (see Clause 3.1)
  • Lot number/Batch number
  • BIS Certification Mark (optional but recommended)

Designation of Pipe (Clause 3.1)

• Includes pipe type, size, and relevant specifications (e.g., material grade)

Packaging

• Pipes should be bundled and protected to avoid damage during transport and storage
• Packaging must maintain pipe integrity and ease of identification via markings

Example Marking Format:

flowchart LR
    A[Pipe Length] -->|Mark both ends| B[Marking with ink/paint]
    A -->|Mark every meter (coil)| C[Hot embossing]
    B & C --> D[Markings include:]
    D --> E[Manufacturer Name]
    D --> F[Pipe Designation]
    D --> G[Batch Number]
    D --> H[BIS Certification Mark]

This ensures traceability, quality assurance, and compliance with IS 14333.

IS 14333 - Explanatory Notes Key Points

1. Reference Standards & Data Sources:

   • ISO/TR 10358-1993: Chemical resistance classification for plastics pipes/fittings.
   • Du Pont data on 'Sclair' polyethylene resins.
   • Mariex (Phillips) data on polyethylene properties and processing.

2. Symbol & Abbreviation Clarifications:

   • Clause 6.1: Replace all mentions of Table 1 with Table 2.
   • Clause 9.2.3.3: Replace Table 4 with Table 7.

3. Tables Substitution Summary:

Practical Note:

• Always use Table 2 instead of Table 1 for data in Clause 6.1.
• Use Table 7 instead of Table 4 in Clause 9.2.3.3 for accurate values.

This ensures correct interpretation of chemical resistance and polyethylene properties as per IS 14333.

IS 14333: Internal Pressure Creep Rupture Test Key Points

Test Conditions (Clause 9.1.2 & Table 6)

Test Specimen (Annex B)

• Length = 10 × Outside Diameter (min 250 mm, max 750 mm)
• Test done ≥ 24 hours post-manufacture
• Specimen immersed in thermostatically controlled water bath
• Controlled internal hydraulic pressure applied

Acceptance Criteria (Clause 8.1)

• No localized swelling, leakage, or weeping
• No burst during test duration

Summary Formula for Specimen Length:

[ L = \max(250,mm, \min(10 \times D_{outside}, 750,mm)) ]

flowchart TD
    A[Pipe Sample] --> B[Cut Specimen (Length = 10 × OD)]
    B --> C[Immerse in Water Bath @ 80°C]
    C --> D[Apply Internal Pressure to Induce Stress]
    D --> E{Hold for Duration}
    E -->|No Failure| F[Pass Test]
    E -->|Failure| G[Fail Test]

This test ensures pipe durability under sustained internal pressure and temperature, critical for long-term service.

IS 14333: Longitudinal Reversion Test Key Points

1. Formula for Longitudinal Reversion (Clause 3.1, Annex C)

[ T = \frac{l_0 - l_1}{l_1} \times 100 ]

• ( l_0 ) = Length before test (mm)
• ( l_1 ) = Length after test (mm)
• ( T ) = Longitudinal reversion percentage (%)

2. Acceptance Criteria (Clause 8.2)

• The longitudinal reversion shall not exceed 3% when tested as per Annex C procedure.

3. Sampling Table for Visual & Dimensional Requirements (Clause 9.2.3.1)

Chemical Resistance Data for HDPE Pipes (IS 14333 - Appendix D)

Key Points:

• Chemical resistance is based on immersion tests at 20°C and 60°C under atmospheric pressure.
• Classification symbols:
  • S: Suitable for continuous use
  • L: Limited suitability; further testing required if under stress
  • NS: Not suitable
• Data derived from ISO/TR 10358-1993 and other sources.

Sample Chemical Resistance Table (Excerpt)

Notes:

• tg-1: Test grade or specific concentration.
• For pipes under mechanical stress or pressure, further testing per ISO 8584-1/2 is mandatory if classification is S or L.
• The table is a preliminary guide; always verify with actual fluid conditions and stresses.

Summary Diagram of Classification Decision Flow

flowchart TD
    A[Chemical Resistance Table] --> B{Classification}
    B -->|S| C[Suitable for continuous use]
    B -->|L| D[Limited use; Further testing required]
    B -->|NS| E[Not suitable]
    D --> F{Under mechanical stress?}
    F -->|Yes| G[Conduct ISO 8584 tests]
    F -->|No| C

For detailed chemical resistance, refer to Clause D-2.2.4 and test per IS 14333 Appendix D.