Specification for hose-clamps and hose bandages for fire brigade use, Part 1: Hose-clamps
1977 Edition

Scope of Specification and Sampling Requirements

Scope: This part prescribes sampling techniques and conformity tests for hose-clamps or similar fire brigade equipment.

Sampling Methodology (Clauses 1.2, 1.3 & Appendix A)

• Sampling is performed on a per-lot basis, with each lot tested independently.
• Sample size and allowable defective units vary according to lot magnitude as shown in Table 1 (Sampling Scale):

• Samples are randomly selected employing random number tables (Clause 1.3).

Quality Expectations (Clause 6.1)

• Forged parts must have no seams, cracks, or surface imperfections; edges should be smoothly rounded.
• Cast parts must be free from blowholes and other casting defects.

Overview Diagram

flowchart TD
    A[Product Lot] --> B{Size of Lot}
    B -->|≤ 8| C[Test all; Zero defects permitted]
    B -->|9-15| D[Sample 8 items; Zero defects permitted]
    B -->|16-25| E[Sample 13 items; Zero defects permitted]
    B -->|26-50| F[Sample 20 items; One defect allowed]
    C & D & E & F --> G[Conduct Defect Tests]
    G --> H{Are defects within limit?}
    H -->|Yes| I[Accept Lot]
    H -->|No| J[Reject Lot]

This method ensures uniform quality assurance through statistically valid sampling and defect limits.

Summary of Hose-Clamp Types (Clause 2.1)

• Type A: Constructed from aluminium alloy sheet.
• Type B: Made using flax canvas straps reinforced with nylon tape.

Main Specifications:

Additional Notes (Clauses 7.1 & 7.2)

• Length tolerance is ±2 mm to ensure clamp matches hose inner diameter.
• Type A clamps include a saw cut (12 x 16 mm deep) to facilitate tightening.
• Type B straps are reinforced by stitching onto nylon tape for durability.

Simplified Diagram

graph LR
A[Fire Hose] --> B[Hole Diameter ≥ 3 mm]
B --> C{Hose-Clamp Type}
C -->|Type A| D[Aluminium Alloy Sheet Clamp]
C -->|Type B| E[Flax Canvas Strap Clamp]
D --> F[Pressure Testing at 70 N/cm² for 5 minutes]
E --> F
F --> G[No Leakage Through Clamp or Strap]

This classification guarantees hose integrity under pressure without leakage or damage.

Summary of Components and Design (Clause 3 & 6.1)

Essential Components

• Type A Clamp (Refer to Fig. 1):
  • Composed of three hinged aluminium alloy sheet sections
  • Equipped with a closing mechanism
  • Includes a quick-release device
• Type B Clamp (Refer to Fig. 2):
  • Made of flax canvas strap with an embedded metal strip

Material Quality (Clause 6.1)

• Forged components must be free from seams, cracks, and surface blemishes; edges should be rounded.
• Cast components must not exhibit blowholes or defects.

Critical Dimensions (Clause 7.5)

• Hinge pin diameter: 6 mm
• Sheet thickness: 2 mm
• Sheet width: 60 mm
• Length tolerance: ±2 mm to ensure proper hose fit when closed

Additional Features

• Nylon tape reinforcement: 25 mm width, stitched
• Saw cut dimension: 12 x 16 mm deep

Summary Table

graph LR
    A[Type A Clamp] --> B[3-section hinged aluminium sheet]
    A --> C[Closing mechanism]
    A --> D[Quick release feature]
    E[Type B Clamp] --> F[Flax canvas strap with metal reinforcement]

This summary encapsulates the primary structural components and dimensional standards according to the specification.

Material Specifications as per IS 5612 Part 1 (1977)

Forgings and Castings (Clause 6.1)

• Forged parts must be free from seams, cracks, and surface defects; all edges to be rounded.
• Castings must not have blowholes or other imperfections.

Aluminium Alloy Sheet (Clause 4.1)

• Shall comply with IS 737-1974, used for Type A clamps and canvas binding ends of Type B.

Aluminium Alloy Castings (Clause 4.3)

• Shall conform to IS 617-1975, designation 4450 (A-8-WP).

Copper Alloy Castings (Clause 4.4)

• Sand Castings:
  • Grade 2 per IS 318-1962 (Leaded Tin Bronze)
  • Grade 3 per IS 304-1961 (High Tensile Brass)
• Die Castings:
  • Grade 3 per IS 292-1961 (Brass)

Summary Table

Notes:

• All materials must satisfy the respective IS standards regarding quality and defect absence.
• Always refer to the latest versions of IS codes for compliance.

flowchart TD
    A[Materials] --> B[Forgings]
    A --> C[Castings]
    B --> D[Defect-free, rounded edges]
    C --> E[No blowholes or surface imperfections]

Overview of Shape and Dimensions (Clause 7.5)

• Types:

  • Type A: As depicted in Fig. 1
  • Type B: As shown in Fig. 2

• Key Measurements:

  • Hinge pin diameter: 6 mm
  • Sheet thickness: 2 mm
  • Sheet width: 60 mm
  • Nylon tape width (stitched): 25 mm
  • Saw cut depth: 12 x 16 mm

• Tolerance:

  • Length tolerance is ±2 mm to ensure the clamp’s inner diameter matches the hose size when secured.

• Material Quality and Finish:

  • Forgings should be free of seams and cracks; edges rounded.
  • Castings to be free from blowholes and other defects.
  • Nylon tape must conform to IS 4228-1967.

Typical Dimension Table (in millimeters)

flowchart LR
    A[Type A Hose Clamp] -->|Fig. 1| B[Dimension Details]
    B --> C[6 mm Hinge Pin]
    B --> D[2 mm Thick Sheet, 60 mm Wide]
    B --> E[25 mm Nylon Tape]
    C & D & E --> F[Material and Finish]
    F --> G[No defects, rounded edges]

This ensures proper fitting and durability as per the standard.

Workmanship and Finishing Requirements (Clauses 6.1 & 6.2)

• Forged components must be free of seams, cracks, and surface flaws.
• All sharp edges should be smoothly rounded to prevent stress concentration and injury.
• Castings should be free of blowholes and other defects.
• Metal surfaces should retain a natural bright finish without any coating or paint.

Summary Table of Requirements

Visual Inspection Checks (Clause 7 & A-2.1)

• Verify shape and dimensions as per Clause 5.
• Inspect workmanship and finish according to Clause 6.
• Perform leakage tests as per Clause 7.

flowchart TD
    A[Begin Inspection] --> B{Check Shape and Dimensions}
    B -->|Pass| C{Evaluate Workmanship and Finish}
    B -->|Fail| D[Reject Component]
    C -->|Pass| E{Conduct Leakage Test}
    C -->|Fail| D
    E -->|Pass| F[Approve Component]
    E -->|Fail| D

This procedure guarantees the quality and compliance of hose-clamps according to the specification.

Leakage Criteria for Hose-Clamps (Clause 7 and related)

Important Points

• Surface Finish (Clause 6.2): Metal surfaces must be naturally bright to prevent corrosion that could cause leakage.

• Sampling for Leakage Testing (Clauses 1.3 and A-1.3): Hose-clamps are randomly selected from each lot using random number tables.

• Inspection Parameters (Clause A-2.1): Each selected clamp is checked for:

  • Shape and dimensional accuracy (Clause 5)
  • Workmanship and surface finish (Clause 6)
  • Leakage under pressure (Clause 7)

• Any clamp found defective in any inspection aspect is rejected.

• Sampling Table for Leakage Tests (Table 1):

Summary

• Sampling size depends on lot quantity.
• Zero tolerance for defects in smaller lots; 1% defective allowed for larger lots.
• Visual checks combined with leakage tests are required for acceptance.

flowchart TD
    A[Select Lot] --> B[Random Sampling as per Table 1]
    B --> C[Visual Inspection: Shape, Size, Finish]
    C --> D{Leakage Test}
    D -->|Pass| E[Accept Lot]
    D -->|Fail| F[Reject Defective Items]

This process ensures leak-tightness and quality assurance of hose-clamps.

Marking Guidelines (Clauses 8.1 & 8.2)

• Each hose-clamp must bear a clear and permanent mark indicating:

  • Manufacturer’s name or trademark
  • Year of production
  • Designated hose size

• Optionally, the Standard Mark may also be applied.

Additional Material and Marking Requirements

• Forged parts must be free from seams, cracks, and surface imperfections; edges rounded.
• Castings must be defect-free and without blowholes.
• Nylon tape for binding should comply with IS 4228-1967.

Typical Marking Format Example:

flowchart LR
    A[Start Production] --> B[Apply Manufacturer Name]
    B --> C[Apply Year of Manufacture]
    C --> D[Indicate Hose Size]
    D --> E[Optional: Apply Standard Mark]
    E --> F[Final Quality Check]

Marking serves for product identification and traceability as per the standard.

Packaging Requirements (Clauses 9.1 & 9.2)

• Type A Hose-Clamps:

  • Each clamp must be individually wrapped in a cellophane cover.
  • Packed inside a corrugated cardboard box.

• Type B Hose-Clamps:

  • Each clamp is similarly enclosed in cellophane.
  • Packed six units per corrugated cardboard carton.

• Corrugated packaging materials should be robust enough to protect contents during handling and shipping.

• Nylon tape used for edge binding must conform to IS 4228-1967.

• Sampling for quality conformity uses random number selection (Clause 1.3).

Packaging Summary Table

This ensures protection, identification, and convenient handling.

Sampling and Acceptance Requirements (Appendix A, Clause 10.1)

Sampling Scale (Table 1)

• Samples must be chosen randomly using random number tables.
• Each lot is tested independently.

Acceptance Criteria

• If the number of defective samples does not exceed the permissible limit, the lot is accepted.
• If defects exceed limits, the lot is rejected.

Summary

• Sample sizes and acceptance limits depend on lot quantity.
• Zero defects allowed for lots up to 25 units; one defective allowed for lots between 26 and 50.
• Random sampling ensures unbiased selection.

flowchart TD
    A[Lot Receipt] --> B{Determine Lot Size}
    B -->|≤8| C[Test all units]
    B -->|9-15| D[Sample 8 units]
    B -->|16-25| E[Sample 13 units]
    B -->|26-50| F[Sample 20 units]
    C & D & E & F --> G[Count Defectives]
    G --> H{Defectives ≤ Allowed?}
    H -->|Yes| I[Accept Lot]
    H -->|No| J[Reject Lot]

This system maintains quality assurance through statistical validation of production lots.

Testing and Acceptance Procedures (Appendix A)

Sampling (Clause A-1.2 & Table 1)

• Sampling is performed lot-wise.
• Samples undergo visual inspections covering shape, size, workmanship, finish, and leakage.

Conformity Criteria (Clause A-2.1)

• Any hose-clamp failing in shape, dimensional accuracy, workmanship, finish, or leakage is considered defective.
• Lot acceptance requires defectives to be within permissible limits.

Inspection Focus Points

• Visual examination of shape and dimensions (Clause 5)
• Workmanship and surface finish (Clause 6)
• Leakage performance (Clause 7)

This approach ensures consistent quality by statistically verifying batch compliance with minimal or no defects.