specials for steel cylinder reinforced concrete pipes

IS 7322: Scope - Key Specifications & Tables

This code covers design and dimensions for steel cylinder reinforced concrete pipes and specials (bends, tees, reducers).

1. Minimum Thickness of Steel Plate for Shell (Clause 4.2)

2. Reinforcement Design (Clause 4.3)

• Follows IS 1916-1963 for cage reinforcement, longitudinal reinforcement, and cover.
• Uses specifications for:
  • High strength deformed steel bars/wires.
  • Hard-drawn steel wire fabric.
  • Structural steel (standard quality).
  • Plain and reinforced concrete practice.

3. Essential Dimensions for Specials (Clause 5.1 & Tables)

• Dimensions for bends, tees, scour tees, reducers are per Figs. 1-4.
• Example: Bend radii and lengths vary with pipe diameter and bend angle.

4. Minimum Clearance from Crown

Classification as per IS 7322 (Steel Cylinder Reinforced Concrete Specials)

1. Classification Reference:

• Clause 2.1: Specials have the same classification as steel cylinder reinforced concrete pipes per IS 1916-1963 (Clause 2.1).

2. Key Design Specifications:

| Nominal Internal Diameter (mm) | Minimum Steel Plate Thickness (mm) | (Clause 4.2) | |-------------------------------|------------------------------------| | 200 to 500 | 2.5 | | 600 to 900 | 5.0 | | 1000 to 1100 | 6.0 | | 1200 to 1500 | 8.0 | | 1600 to 1800 | 10.0 |

3. Marking Requirements (Clause 10.1):

• Size of special
• Class of special
• Radius of bend (for bends)
• Date of manufacture
• Manufacturer’s name or trademark

4. Bend Dimensions (from Table 4.3 excerpt):

• Internal diameter and bend radius vary by angle (61° to 90°, 46° to 60°, 31° to 45°, 30° bends).
• Example for 300 mm diameter:
  • Radius for 61°-90° bends: 460 mm
  • Length for 61°-90° bends: 690 mm

Summary:
Classification aligns with IS 1916 pipe classes. Minimum steel plate thickness depends on diameter. Specials must be clearly marked, and bend dimensions follow detailed tables for manufacturing accuracy.

flowchart TD
    A[Steel Cylinder Reinforced Concrete Specials] --> B[Classification per IS 1916]
    A --> C[Minimum Steel Plate Thickness]
    C --> D[200-500 mm: 2.5 mm]
    C --> E[600-900 mm: 5.0 mm]
    C --> F[1000-1100 mm: 6.0 mm]
    C --> G[1200-1500 mm: 8.0 mm]
    C --> H[1600-1800 mm: 10.0 mm]
    A --> I[Marking Requirements]
    I --> J[Size, Class, Bend Radius, Date, Manufacturer

IS 7322: Key Materials Specifications & Tables

1. Reinforcement Materials (Clause 3.3.1)

• Mild steel & medium tensile steel bars: IS 432 (Part 1)-1982
• High strength deformed steel bars: IS 1786-1985
• Hard-drawn steel wire fabric: IS 1566-1982
• Rolled structural steel: IS 226-1975

2. Minimum Thickness of Steel Plate for Shell (Clause 4.2)

3. Bend Dimensions (Clause 4.3, Table excerpt)

4. Minimum Clearance from Crown (mm)

Notes:

• Reinforcement and cover conform to IS 1916 (Clauses 4.2, 4.4, 4.5).
• Dimensions in millimeters.
• Refer IS 1916 for detailed end dimensions of bends, tees, reducers.

flowchart LR
    A[Materials] --> B[Reinforcement]
    B --> B1[Mild/Medium Tensile Steel (IS 432)]
    B

IS 7322 - Design Key Formulas, Tables, and Specifications

1. Reinforcement Requirements (Clause 3.3.1)

• Reinforcement types:
  • Mild/medium tensile steel bars (IS 432 Part 1-1982)
  • High strength deformed bars (IS 1786-1985)
  • Hard-drawn steel wire fabric (IS 1566-1982)
  • Structural steel (IS 226-1975)

2. Minimum Thickness of Steel Plate for Shell (Clause 4.2 - Table 1)

3. Bend Dimensions (Clause 4.3 - Table 4)

• Bend radii and lengths vary by internal diameter and bend angle (31° to 90°).
• Example for 200 mm diameter at 61°-90° bends:
  • Radius (R) = 340 mm
  • Length (L3) = 530 mm

4. Minimum Clearance from Crown (Fig. 1 & Table)

Summary Diagram: Reinforcement & Plate Thickness Relation

graph TD
A[Internal Diameter] --> B{Diameter Range}
B -->|200-500 mm| C[Plate Thickness 2.5 mm]
B -->|600-900 mm| D[Plate Thickness 5.0 mm]
B -->|1000-1100 mm| E[Plate Thickness 6.0 mm]
B -->|1200-1500 mm| F[Plate Thickness 8.0 mm]
B -->|1600-180

Here is a concise summary of key dimensions, thicknesses, and specifications from IS 7322:

1. Nominal Thickness of Flange (Table 2, Clause 5.1.1)

• Actual flange thickness = Nominal thickness - max 5 mm (machining allowance).
• Flange details per IS:1538 (holes, PCD, OD).

2. Minimum Thickness of Steel Plate for Shell (Table 1, Clause 4.2)

3. Dimensions for Bends (Clause 5.1, Fig. 1)

• Radius (R) and Length (L) depend on bend angle and nominal internal diameter.
• Example for 61° to 90° bends:

4. Minimum Clearance from Crown (for bends, tees)

Key Reinforcement Specifications from IS 7322

Types of Reinforcement (Clause 3.3.1)

• Mild and medium tensile steel bars (IS: 432 Part 1-1982)
• High strength deformed steel bars (IS: 1786-1985)
• Hard-drawn steel wire fabric (IS: 1566-1982)
• Rolled structural steel (IS: 226-1975)

Reinforcement Cage (Clause 7.2)

• Reinforcement cage extends throughout the special
• Composed of spirals or rings (circular shape) and straight bars
• Spirals/rings can be wound directly on the steel special or on collapsible frames/drums

Design Provisions (Clause 4.3)

• Follow IS: 1916-1963 clauses 4.2, 4.4, 4.5 for:
  • Cage reinforcement
  • Nominal longitudinal reinforcement
  • Concrete cover

Important Tables

(Refer to IS 1916 for detailed bend lengths and radii)

Minimum Clearances from Crown (mm)

Summary Formula for Reinforcement Area (from IS 1916)

[ A_s = \frac{M}{0.87 f_y d} ]

• (A_s) = Area of steel required
• (M) = Moment
• (f_y) = Yield strength

IS 7322 - Manufacture of Steel Cylinder Reinforced Concrete Specials: Key Points

Marking Requirements (Clause 10.1)

Each special must be clearly marked with:

• Size of special
• Class of special
• Radius of bend (for bends)
• Date of manufacture
• Manufacturer’s name or trademark

Minimum Thickness of Steel Plate for Shell (Clause 4.2, Table 1)

Radius and Length for Bends (Clause 4.3, Table)

Minimum Clearance from Crown for Specials

Summary Diagram: Manufacture Marking & Dimensions

graph TD
A[Manufacture of Specials] --> B[Marking: Size, Class, Radius, Date, Manufacturer]
A --> C[Steel Plate Thickness per Diameter]
A --> D[Bend Radius & Length per Diameter & Angle]
A --> E[Clearance from Crown per Diameter Range]

References:

• IS 1916-1963 for reinforcement and end dimensions
• Cement & steel specifications as per referenced IS codes

This ensures quality control and dimensional accuracy in

IS 7322: Key Testing Formulas, Tables & Specifications

1. Compressive Strength Test (Clause 3.4.2):

• Conducted on 150 mm concrete cubes per IS 456-1978 & IS 516-1959.
• Cube strength, ( f_c = \frac{P}{A} ) where:
  • (P) = load at failure (N)
  • (A = 150 \times 150 = 22500 , mm^2)

2. Rounding Off (Clause 0.5):

• Follow IS 2-1960 for rounding test results to the same significant figures as specified values.

3. Dye-Penetration Test (Clause 8.3):

• Performed as per IS 3658-1981 to detect surface cracks or defects.

4. Reinforcement & Cover (Clause 4.3):

• Follow IS 1916-1963 clauses 4.2, 4.4, 4.5 for cage reinforcement, nominal longitudinal reinforcement, and cover.

Table: Minimum Clearances for Steel Cylinder Reinforced Concrete Pipes

Notes:

• Refer IS 1916-1963 for detailed dimensions of bends, tees, reducers.
• Testing and workmanship must comply with relevant IS codes for quality assurance.

flowchart TD
    A[Test Specimen Preparation] --> B[Compressive Strength Test (IS 516)]
    B --> C[Load Applied on Cube]
    C --> D[Measure Failure Load P]
    D --> E[Calculate Strength \(f_c = \frac{P}{A}\)]
    E --> F[Round off as per IS 2-1960]
    F --> G[Evaluate Compliance]

This summary ensures compliance with IS 7322 testing requirements and related

IS 7322: Workmanship and Finish Key Points

1. Surface Quality (Clause 9.1.1)

• Outside and inside surfaces must be smooth, dense, and hard.
• No cement wash or coatings unless agreed between purchaser and manufacturer.

2. Marking on Specials (Clause 10.1)

Each special must be clearly marked with:

• Size of special
• Class of special
• Radius of bend (for bends)
• Date of manufacture
• Manufacturer’s name or registered trademark

3. Dye-Penetration Test (Clause 8.3)

• Conducted as per IS 3658-1981 to detect surface flaws.

4. Rounding Off (Clause 3.4.3)

• Test results rounded per IS 2-1960, maintaining the same significant figures as specified values.

Summary Table: Surface Finish & Marking Requirements

flowchart TD
    A[Manufacture] --> B[Surface Finish Check]
    B -->|Smooth & Dense| C[Marking]
    C --> D[Dye Penetration Test (IS 3658)]
    D --> E[Final Inspection]
    E --> F[Packaging & Dispatch]

This ensures durable, defect-free specials with traceability and quality assurance.

IS 7322: Marking of Special Concrete Pipes - Key Specifications

Clause 10.1 - Mandatory Markings on Each Special:

• Size of special (Nominal internal diameter)
• Class of special
• Radius of bend (for bends)
• Date of manufacture
• Name of manufacturer or registered trademark

Clause 10.1.1:

• Optional ISI Certification Mark may be included, indicating compliance with Indian Standards and quality control.

Related Tables & Dimensions

Bend Dimensions (Radius R and Length L) for Various Nominal Diameters (mm)

(Refer IS 1916-1963 for full table and other bend angles)

Summary

• Markings ensure traceability & compliance.
• Include size, class, bend radius, date, manufacturer.
• ISI mark indicates certified quality.
• Steel plate thickness and bend dimensions are standardized per nominal diameter.

graph TD
A[Special Concrete Pipe] --> B[Marking]
B --> C[Size]
B --> D[Class]
B --> E[Radius of Bend]
B -->