Specification for suction wrenches for fire brigade use

IS 4643: Scope and Key Specifications for Suction Wrenches

• Scope (Clause 1.1):
  Covers materials and dimensions for conventional type suction wrenches used by fire services.

• Types Covered:
  Only conventional (fixed) type suction wrenches are specified in this revision.

• Sizes (Clause 3.1 & Table 1):
  Four sizes with fixed Length A = 250 mm and Diameter B = 22 mm. Other dimensions vary as below:

• Tolerances:

  • Length A, Radius C ± 2 mm
  • Width D ± 1 mm
  • Diameter E ± 1 mm
  • Depth F ± 1 mm
  • Angular tolerance ± 1°

• Rounding Off (Clause 0.4):
  Values must be rounded per IS 2-1960 rules, matching the significant figures of specified values.

flowchart LR
    A[Fire Service Requirement] --> B[Conventional Suction Wrench]
    B --> C{Four Sizes}
    C --> D[Size 1: Width 55 mm, Depth 21 mm]
    C --> E[Size 2: Width 68 mm, Depth 25 mm]
    C --> F[Size 3: Width 80 mm, Depth 25 mm]
    C --> G[Size 4: Width 88 mm, Depth 25 mm]

This summary aligns with IS 4643's scope and dimensional requirements for conventional suction wrenches.

IS 4643: Materials & Dimensions for Suction Wrenches

Materials (Clause 2.1)

• Mild steel bar for wrenches shall conform to IS 226:1975 (Specification for mild steel).

Dimensions (Clause 3.1, Table 1 & Fig.1)

Four sizes of suction wrenches specified with these key dimensions (all tolerances apply):

Notes:

• Dimensions vary slightly for the four wrench sizes.
• Rounding off of values should follow IS 2:1960 rules.

flowchart LR
    A[Material: Mild Steel (IS 226)] --> B[Manufacture Suction Wrench]
    B --> C[Dimensions per Table 1]
    C --> D[Length (A) = 250 mm ±2 mm]
    C --> E[Diameter (B) = 22 mm ±2 mm]
    C --> F[Radius (C) = 78-84 mm ±1°]
    C --> G[Width (D) = 55-88 mm ±1 mm]
    C --> H[Diameter (E) = 23-25 mm +1 mm]
    C --> I[Depth (F) = 15-25 mm ±1 mm]

Summary: Use mild steel per IS 226, manufacture suction wrenches to the given dimensional tolerances, and apply IS 2 rounding rules for compliance checks.

IS 4643: Suction Wrench — Shape and Dimensions

Key Specifications (Clause 3.1 & Table 1)

• Four sizes of suction wrenches with fixed length A = 250 mm.
• Dimensions vary mainly in:
  • Diameter B = 22 mm (±2 mm)
  • Radius C = 78 to 84 mm (±2 mm)
  • Width D = 55 to 88 mm (±1 mm)
  • Diameter E = 23 to 25 mm (+1 mm)
  • Depth F = 15 mm (±1 mm)
• Angular tolerance on radius C: ±1°

Material (Clause 2.1)

• Mild steel bar conforming to IS 226-1975 (Standard quality structural steel).

Quality (Clause 4.1)

• Wrenches must be free from burrs, edges smoothened and filled.

Visual Concept (Fig. 1: Conventional Suction Wrench)

graph LR
A[Length A = 250 mm]
B[Diameter B = 22 mm]
C[Radius C = 78-84 mm]
D[Width D = 55-88 mm]
E[Diameter E = 23-25 mm]
F[Depth F = 15 mm]

A --> B --> C --> D --> E --> F

This ensures compatibility and standardization for fire service equipment.

IS 4643 - Manufacturing Requirements for Suction Wrenches

Key Specifications:

• Material: Mild steel bars conforming to IS 226-1975 (Clause 2.1).
• Types: Four sizes of conventional (fixed) suction wrenches (Clause 3.1).
• Dimensions: As per Table 1 and Fig. 1.

Table 1: Dimensions of Suction Wrench (All dimensions in mm unless stated)

Additional Notes:

• Rounding off: Final test or calculation values must be rounded as per IS 2-1960 to match the significant figures of the specified values (Clause 0.4).
• The standard focuses on conventional fixed type suction wrenches.

flowchart LR
    A[Material: Mild Steel (IS 226)] --> B[Manufacturing]
    B --> C[Shape & Dimensions]
    C --> D[4 Sizes (Table 1)]
    D --> E[Fixed Type Suction Wrench (Fig. 1)]

This ensures consistent quality and interchangeability of suction wrenches per IS 4643.

IS 4643 - Marking for Suction Wrenches

Key Specifications (Clause 5.1)

Suction wrenches must be clearly and permanently marked with:

• Manufacturer's name or trade-mark
• Size and reference of coupling for which the wrench is suitable

Dimensions of Suction Wrenches (Clause 3.1, Table 1)

• Length A fixed at 250 mm
• Diameter B fixed at 22 mm
• Radius C varies between 78 to 84 mm
• Width D varies between 55 to 88 mm
• Diameter E varies between 23 to 25 mm
• Depth F fixed at 15 mm

Rounding Off (Clause 0.4)

• Final values (test results or calculations) must be rounded per IS 2-1960.
• Retain the same number of significant digits as the specified value.

flowchart TD
    A[Suction Wrench] --> B[Marking]
    B --> C[Manufacturer's Name/Trade-mark]
    B --> D[Size & Coupling Reference]
    A --> E[Dimensions]
    E --> F[Length A = 250 mm]
    E --> G[Dia B = 22 mm]
    E --> H[Radius C = 78-84 mm]
    E --> I[Width D = 55-88 mm]
    E --> J[Dia E = 23-25 mm]
    E --> K[Depth F = 15 mm]

Summary: IS 4643 mandates permanent marking with manufacturer and size details, specifies four sizes with exact dimensions and tolerances, and requires rounding off test/calculated values as per IS 2-1960.

IS 4643: Inspection and Testing Key Points

• Rounding off results (Clause 0.4):
  Test results must be rounded per IS 2-1960 rules. The rounded value retains the same number of significant digits as the specified standard value.

• Dimensions & Tolerances (Clause 3.1, Table 1):
  Four sizes of suction wrenches with fixed dimensions and tolerances:

• Marking (Clause 5.1.1):
  Suction wrenches may bear the ISI Certification Mark, ensuring compliance with inspection, testing, and quality control per ISI regulations.

Summary for Inspection & Testing:

• Perform dimensional checks against Table 1 with specified tolerances.
• Round test results as per IS 2-1960.
• Confirm ISI mark for certified products indicating quality assurance.

flowchart LR
    A[Start: Suction Wrench Sample] --> B[Measure Dimensions]
    B --> C{Dimensions within Tolerance?}
    C -- Yes --> D[Perform Functional Tests]
    C -- No --> E[Reject / Rework]
    D --> F[Round off Results per IS 2-1960]
    F --> G{Pass Quality Criteria?}
    G -- Yes --> H[Mark ISI Certification]
    G -- No --> E
    H --> I[Approved for Use]

This ensures compliance with IS 4643 inspection and testing requirements.

Rounding Off Numerical Values as per IS 4643

• According to Clause 0.4, all final observed or calculated values must be rounded off following IS 2:1960 rules.
• The number of significant figures in the rounded value should match those in the specified value in IS 4643.
• IS 2:1960 rounding rules summary:
  • If the digit to be dropped is less than 5, the preceding digit remains unchanged.
  • If the digit to be dropped is 5 or more, the preceding digit is increased by 1.
  • Trailing zeros are retained to maintain the specified number of significant digits.

Example Table Extract (Clause 3.1 - Dimensions of Suction Wrench)

Note: Dimensions must be rounded off respecting the tolerances and significant digits.

Summary

• Always round off test/calculated values per IS 2:1960.
• Maintain significant figures consistent with the standard's specified values.
• Apply tolerances as given for dimensions (±1 mm, ±2 mm, ±1°) in design and verification.

flowchart TD
    A[Calculate/Observe Value] --> B{Check Number of Significant Figures}
    B -->|Match IS 4643 Specified| C[Round off per IS 2:1960 Rules]
    C --> D[Report Final Value]

IS 4643: Key Specifications for Suction Wrenches

1. Sizes & Dimensions (Clause 3.1, Table 1 & Fig. 1)

Four sizes of conventional (fixed) suction wrenches are specified with these key dimensions:

• Length A: 250 mm fixed for all sizes.
• Diameter B: 22 mm fixed.
• Radius C: 78 to 84 mm with ±1° tolerance.
• Width D: 55 to 88 mm.
• Diameter E: 23 to 25 mm.
• Depth F: 15 mm.

2. Rounding Off (Clause 0.4)

• Follow IS 2:1960 for rounding off test or calculation results.
• Retain the same number of significant figures as the specified values.

Summary Diagram of Dimensions (Fig. 1 Conceptual)

graph LR
A[Length A (250 mm)]
B[Diameter B (22 mm)]
C[Radius C (78-84 mm, ±1°)]
D[Width D (55-88 mm)]
E[Diameter E (23-25 mm)]
F[Depth F (15 mm)]
A --> B --> C --> D --> E --> F

This standard ensures uniformity and interchangeability of suction wrenches used in fire services.