Asbestos Cement Pressure Pipes and Joints
2003 Edition

Overview of IS 1592 Scope with Key Formulas and Tables

1. Dimensional Tolerances on Pipes (Clause 1.5)

2. Finished End External Diameter (Clause 2.5)

• Nominal diameter ( d = ) as specified.
• For pipes exceeding 500 mm, internal diameter is checked at 3 points per end spaced 60° apart with ±1 mm precision.
• None of the six measurements should be less than the formula value.

3. Nominal Wall Thickness Tolerances (Clause 2.5c)

• No upper tolerance limit on thickness.
• Minimum thickness at any point must be nominal minus tolerance.
• Average thickness must be at least nominal; up to 10% samples may have negative tolerance.

4. Length Tolerance (Clause 2.5d)

• Length tolerance allowed: +3 mm / -0 mm.

5. Optional Straightness Deviation Test (Clause 2.5e)

6. Dimensions and Weight of AC Couplings (Clause 4)

Categorization of Pipes According to IS 1592

1. Classification by Hydraulic Test Pressure (Table 1)

• Pipes with nominal diameter up to 1000 mm are classified by TP.
• Hydraulic working pressure (WP) must not exceed 50% of TP.
• Total WP including surge pressure must not exceed 75% of TP.

2. Pressure Ratios (Table 2)

• BP = Bursting Pressure
• TP = Hydraulic Test Pressure
• WP = Working Pressure

3. Nominal Diameters (Table 3)

4. Pipes with Diameters Above 1000 mm

• Not classified under standard classes.
• Design to be based on purchaser’s requirements and project specifications.
• Must consider crushing loads according to relevant IS guidelines.

Summary:

• Select pipe class based on hydraulic test pressure.
• Ensure working pressures comply with specified limits.
• Use pressure safety ratios as per Table 2.
• For diameters >1000 mm, customize design accordingly.

Summary of IS 1592 Dimensions and Allowable Deviations

1. Permissible Variations on Pipe Measurements (Clauses 1.5 & 2.5)

• For wall thickness at joint faces, negative tolerances depend on nominal thickness:

• No upper limit on positive tolerance.

2. Tolerances on External Diameter at Pipe Ends (Clause 3.4.1.4)

3. Straightness Deviation Limits (Optional Test, Clause 2.5e)

Note: length refers to the pipe segment length under consideration.

4. Dimensions and Weight of Asbestos Cement Couplings

Overview of Physical and Mechanical Features as per IS 1592

1. Dimensional Tolerances (Clause 1.5)

2. Mechanical Strength Requirements (Clause 3.4.3)

• Testing must confirm unit strength meets or exceeds specified minimums.
• For specimens not immersed, minimum unit bursting strength must be at least 24 N/mm², calculated using manufacturing diameter if different from nominal.

3. Geometric Accuracy (Clause 4.2.1)

• Specifies dimensional and shape accuracy requirements (details not included here).

Key Calculation:

Bursting Strength (σ_b) = Load at failure / Cross-sectional area

Where:

• Cross-sectional area approximated by π × (outer diameter × thickness) for thin-walled pipes
• d_o = outer diameter
• t = wall thickness

flowchart LR
    A[Manufacturing Process] --> B[Dimensional Checks]
    B --> C[Mechanical Testing]
    C --> D[Verify Unit Strength ≥ Specified]
    D --> E[Accept or Reject]

Summary: Confirm dimensional tolerances and verify mechanical strength meets minimums, especially bursting strength ≥ 24 N/mm² for non-immersed specimens.

Essential Details on Jointing and Sealing in IS 1592

1. Sealing Capability (Clause 4.2.2)

• Joints must resist the prescribed hydraulic test pressure while accommodating the maximum angular deflection recommended by the manufacturer.
• Test pressures are as per Clause 3.5(a)(1), typically at or above design pressure for safety margin.

2. Fluid Compatibility (Clause 7.1)

• Manufacturers must be informed about the fluid characteristics to ensure the joint sealing rings are chemically compatible.
• Additional chemical resistance testing may be necessary depending on the fluid.

3. Sampling Verification (Clause 5.2.1)

• Sealing and mechanical properties can be confirmed through sampling tests when requested.

4. Dimensional Requirements (Clause 3.4.1.4)

• Pipe end sections with rubber rings must adhere to external diameter tolerances.
• Ends must be free from defects to maintain watertight joints.
• Shape of pipe ends is determined by the manufacturer to suit the joint type.

Typical Hydraulic Sealing Test Parameters

Joint Sealing Test Workflow

flowchart LR
    A[Pipe with Rubber Seal] --> B[Joint Assembly]
    B --> C[Apply Hydraulic Pressure]
    C --> D{Is Angular Deviation Max?}
    D -->|Yes| E[Check for Leakage]
    D -->|No| F[Adjust Joint Angle]
    E --> G{Leakage Detected?}
    G -->|No| H[Pass]
    G -->|Yes| I[Fail - Requires Correction]

Note: Always consult manufacturer specifications for joint deflection limits and ring compatibility with the conveyed fluid.

Marking and Identification Requirements under IS 1592

1. Mandatory Markings (Clause 3.6.1)

Every pipe must be clearly and permanently marked with:

• Manufacturer’s identity
• Manufacturing date and batch number
• Nominal diameter
• Pipe class designation
• Warning symbol as per IS 12081 (Part 2)

2. BIS Certification Mark (Clause 3.6.2)

• Pipes may optionally display the BIS Standard Mark indicating conformity.

3. Dimensional Tolerances (Clause 1.5)

4. Verification (Clause 5.1.2)

• Appearance, dimensions, and markings must be checked for each batch.

Marking Information Diagram

graph TD
    A[Pipe] --> B[Manufacturer Name]
    A --> C[Manufacture Date & Batch]
    A --> D[Nominal Diameter]
    A --> E[Pipe Class]
    A --> F[Warning Label (IS 12081 Pt.2)]
    A --> G[BIS Mark (optional)]

This marking system ensures traceability, quality assurance, and safety compliance.

Inspection and Acceptance Testing Procedures in IS 1592

1. Measurement Protocols (Clause 6.0)

• Internal diameter: Average of three measurements.
• Thickness: Average of three measurements excluding groove areas.
• Weight: Measured per pipe in kilograms.

2. Acceptance Tests (Annex C)

• Tests to be determined by purchaser at ordering (e.g., internal hydraulic pressure tightness).
• Scheduling by mutual agreement, tests must be completed before dispatch and within four weeks of sampling.
• Purchaser may inspect or witness tests at manufacturer’s premises.
• Manufacturer bears cost of mandatory and initially agreed optional tests; purchaser covers extra optional tests.
• Inspection may be 100% or by sampling; failing samples require 100% inspection.
• Manufacturer must provide test certificates if purchaser is absent during testing.

3. Inspection Summary Table

flowchart TD
    A[Order Placement] --> B{Is Testing Required?}
    B -- Yes --> C[Schedule and Conduct Tests]
    C --> D{Tests Passed?}
    D -- Yes --> E[Proceed to Delivery]
    D -- No --> F[Reinspection or Full Inspection]
    E --> G[Issue Test Certificate]

This ensures pipes comply with IS 1592 quality and performance standards before delivery.

Summary of Sampling and Inspection as per IS 1592

Sampling Procedures (Clauses 5.2 & 5.2.3)

• Sampling follows IS 7639 guidelines for inspection and acceptance.
• Inspection lots must consist of pipes with identical diameter and class.
• For pipes over 1000 mm diameter, sampling requires purchaser and manufacturer agreement.

Dimensional Tolerances (Clause 1.5)

Measurement Notes (Clause 6.0)

• Internal diameter: Average of three measurements.
• Thickness: Average excluding groove sections.
• Weight: Per individual pipe.

Acceptance Testing (Annex C)

• Tests agreed at order placement; purchaser informs manufacturer.
• Purchaser may inspect tests and stocks.
• Manufacturer responsible for cost of compulsory and initially agreed optional tests.
• Sampling may replace full inspection but failing lots require 100% reinspection.
• All tests must complete before delivery and within four weeks after sampling.
• Manufacturer issues certificate following tests.

flowchart TD
    A[Order Received] --> B[Sampling per IS 7639]
    B --> C{Diameter > 1000 mm?}
    C -- Yes --> D[Agreement Between Purchaser & Manufacturer]
    C -- No --> E[Proceed with Sampling]
    E --> F[Perform Agreed Tests]
    F --> G{Tests Passed?}
    G -- Yes --> H[Accept Lot]
    G -- No --> I[Perform 100% Inspection]
    I --> J{Inspection Passed?}
    J -- Yes --> H
    J -- No --> K[Reject Lot]

This protocol guarantees compliance with IS 1592 acceptance criteria for quality.

Manufacturing Specifications under IS 1592

1. Dimensional Allowances (Clauses 1.5 & 2.5)

Wall Thickness Lower Limit Table:

• No restriction on positive tolerance.
• Thickness at any point must not be less than nominal minus tolerance.
• Average thickness must be at least nominal with maximum 10% samples allowed below tolerance.

2. Internal Diameter Measurement (Clauses 6.0 & 2.5)

• Average internal diameter determined from three measurements per pipe end spaced approximately 60° apart.
• Accuracy ±1 mm.
• None of the six measurements should be smaller than the minimum allowed by formula.

3. Straightness (Optional Test, Clause 2.5)

L = length of pipe segment

4. Acceptance Testing Procedures

IS 1592 Recommendations for Choosing and Installing Asbestos Cement Pipes

Key Dimensions and Tolerances

1. Pipe Size Specifications

• External diameter as specified in Clause 2.5.
• For pipes larger than 500 mm nominal diameter, internal diameter is to be measured at three points per end, spaced 60° apart, with ±1 mm accuracy.
• All measurements must meet minimum formula requirements.

2. Wall Thickness Tolerances

• No upper limit on thickness tolerance.
• Thickness at any section must be no less than nominal minus tolerance.
• Average thickness must meet nominal; up to 10% samples may have negative tolerance.

3. Length Tolerances

• Minimum 90% of pipes supplied must be standard length within tolerance.
• Remaining pipes should be at least 2 meters long.
• Total length delivered must not be less than the ordered length.
• Short length pipes are tested similarly to standard lengths.

4. Optional Straightness Limits

l = length under consideration for straightness

Additional Recommendations

• For aggressive water or soil environments, inform manufacturer to determine suitable material treatments.
• Safety protocols as per IS 11769 (Part 1) must accompany deliveries.
• Internal hydraulic pressure testing is required for acceptance.
• If short pipes are supplied, additional joints must be provided free of charge.

Safety and Compliance Highlights from IS 1592

1. Tolerances for Asbestos Cement Couplings (Clause 1.5)

2. Dimensions and Weight of AC Couplings (Annex B, Clause 4.1.3)

(Complete table available in Clause 4.1.3)

3. Mechanical Strength and Durability (Clause 3.4.3)

• Couplings must meet dimensional and mechanical strength specifications.
• Compliance with ICS 23.040.50 and 91.100.40 standards ensures operational safety.

Summary:

• Adherence to dimensional tolerances guarantees proper fitting.
• Weight and size data assist in quality control and selection.
• Mechanical properties ensure safety under working conditions.

flowchart TD
    A[AC Coupling] --> B{Check Dimensions}
    B -->|Within Tolerance| C[Accept]
    B -->|Outside Tolerance| D[Reject]

Summary of Annexes and References in IS 1592

Key Measurement Specifications:

Tolerances (Clause 1.5):

Annex B: Sample Dimensions & Weight of AC Couplings

(Refer to Annex B for complete listings)

Annex C: Acceptance Testing

• Tests to be agreed upon during order placement.
• Internal hydraulic pressure testing per Clause 3.5(a)(1).
• Purchaser access allowed for inspection.
• Manufacturer covers costs for mandatory and agreed optional tests.
• Sampling inspection permissible; failing lots require full inspection.
• All tests completed before shipment and within four weeks after sampling.
• Manufacturer must issue a certificate post testing.

Annex A: Sample Referenced Indian Standards