Specification for Blower and Exhauster for Fire Fighting

IS 941: Scope - Key Specifications & Materials

Scope:
IS 941 covers specifications for blowers and exhausters used in fire fighting, detailing materials, construction, and performance requirements.

Key Material Specifications (Table 1)

Alternative Power Source (Clause 2.2)

• Where electric supply is available, 3-phase induction motor (2.2 kW) per IS 325:1978 can replace the petrol engine.
• Flameproof enclosures should conform to IS 2148:1981.

Summary Diagram: Material Flow for Fire Fighting Blower

graph TD
    A[Impeller] -->|Aluminium| B[Grade 4423 IS 617:1975]
    C[Casing] -->|Aluminium| B
    D[Suction Mouth] -->|Aluminium| B
    E[Exhaust Pipe] -->|Canvas| F[IS 1424:1977]
    G[Engine] -->|Petrol 2.5 kW| H[IS 7347:1974]
    G -->|Diesel 3.23 kW| I[IS 10001:1981]
    J[Frame] -->|MS Pipe| K[IS 1239 (Part 1):1979]
    L[Wire Fabric Steel] -->|Steel| M[IS 4948:1974]

This ensures compliance with IS 941 for materials, engine types, and construction for fire fighting blowers and exhausters.

IS 941 Key References: Materials & Specifications

Table 1: Material Requirements for Components

Alternate Engine (Amendment 1993):

• Petrol engine 2.5 kW or lightweight diesel engine 3.23 kW (IS: 10001-1981)

Electric Motor Option:

• 3-phase induction motor 2.2 kW as per IS: 325-1978 with flameproof enclosures IS: 2148-1981

Notes:

• Materials must conform strictly to the specified IS grades.
• Engines and motors must comply with their respective IS specifications for performance and safety.
• For detailed mechanical and electrical design, refer to the respective IS codes mentioned.

flowchart LR
    A[Impeller, Casing, Suction Mouth] -->|Aluminium| B[IS: 617-1975 Grade 4423]
    C[Exhaust Pipe] -->|Canvas| D[IS: 1424-1977]
    E[Petrol Engine] -->|2.5 kW| F[IS: 7347-1974]
    G[Diesel Engine] -->|3.23 kW| H[IS: 10001-1981]
    I[Frame] -->|MS Pipe| J[IS: 1239 (Part 1)-1979]
    K[Wire Fabric Steel] -->|Steel| L[IS: 4948-1974]
    M[Electric Motor] -->|2.2

IS 941: Definitions - Key Material Specifications (Clause 3.1, Table 1)

Notes:

• Alternative to petrol engine: 3-phase induction motor (2.2 kW) as per IS:325-1978 with or without flameproof enclosure IS:2148-1981.
• Diesel engine option: 3.23 kW lightweight diesel engine per IS:10001-1981.

Summary Diagram: Material Flow for Fire Fighting Blower Components

graph LR
A[Impeller] -->|Aluminium Grade 4423| B(Blower Assembly)
C[Casing] -->|Aluminium Grade 4423| B
D[Suction Mouth] -->|Aluminium Grade 4423| B
E[Exhaust Pipe] -->|Canvas IS:1424| B
F[Frame] -->|MS Pipe IS:1239| B
G[Wire Fabric Steel] -->|Steel IS:4948| B
H[Engine] -->|Petrol IS:7347 or Diesel IS:10001| B

This ensures compliance with IS 941 material standards for fire fighting blowers and exhausters.

IS 941: General Requirements - Key Specifications & Materials

Material Requirements (Clause 3.1, Table 1):

Alternate Power Source (Clause 2.2):

• Instead of petrol engine, a 3-phase induction motor of 2.2 kW as per IS:325-1978 can be used.
• Flameproof enclosures as per IS:2148-1981 if required.

Summary

• Aluminium Grade 4423 is standard for impeller, casing, and suction mouth.
• MS pipes for frame and lifting handles.
• Canvas for exhaust pipe.
• Engines/motors must conform to specified IS standards.
• Material quality ensures durability and compliance with fire-fighting equipment standards.

graph TD
    A[Blower/Exhauster Components] --> B[Impeller - Aluminium (IS:617)]
    A --> C[Casing - Aluminium (IS:617)]
    A --> D[Suction Mouth - Aluminium (IS:617)]
    A --> E[Exhaust Pipe - Canvas (IS:1424)]
    A --> F[Frame - MS Pipe (IS:1239)]
    A --> G[Wire Fabric Steel (IS:4948)]
    A --> H[Engine - Petrol (IS:7347) or Diesel (IS:10001) or 3-phase motor (IS:325)]

This ensures compliance with IS 941 general requirements for fire-fighting blowers and exhausters.

IS 941: Performance Requirements Summary

1. Material Specifications (Clause 3.1, Table 1)

2. Engine Performance (Clause 3.23)

• Lightweight diesel engine capacity: 3.23 kW
• Reference: IS 10001:1981 for constant speed diesel engines up to 20 kW.

3. Weight & Mounting (Clause 4.1)

• Total unit weight (engine + impeller + fuel) ≤ 60 kg
• Impeller: Overhung type mounted on engine shaft extension.

4. Performance Criteria (Clause 10.1)

• Each unit must conform to the standard's test requirements.
• Testing includes material conformity, engine performance, and assembly integrity.

Key Notes:

• Use IS 2:1960 rounding for test results.
• Design emphasizes performance-based criteria for fire-fighting blowers and exhausters.
• Engine and impeller must be securely mounted for reliable operation.

flowchart LR
    A[Material Selection] --> B[Manufacturing]
    B --> C[Assembly: Engine + Impeller]
    C --> D[Weight Check ≤ 60 kg]
    D --> E[Performance Testing]
    E --> F{Conforms to IS 941?}
    F -- Yes --> G[Approved Unit]
    F -- No --> H[Rework/Reject]

For detailed design and testing, refer to IS 941 clauses and IS 10001 for engine specs.

IS 941: Testing Procedures Key Points

1. General Testing (Clause 10.1)

• Each firefighting equipment must be checked against the standard's requirements.
• Testing ensures conformity to material, performance, and safety criteria.

2. Air Delivery Test (Clause 5.1.3)

• The cylindrical airway is divided into equal square areas along the diameter D.
• Measurements are taken at the center of each square using an anemometer.
• Number of measurement points depends on the ratio of D to the anemometer vane diameter.

3. Material Specifications (Clause 3.1 & Table 1)

Summary Diagram: Air Delivery Test Setup

flowchart LR
    A[Cylindrical Airway Diameter D]
    B[Divide into square areas (D/d)]
    C[Place anemometer vane center at each square center]
    D[Measure air velocity at each point]
    A --> B --> C --> D

Note: For detailed measurement points and acceptance criteria, refer to Fig. 2B and associated tables in IS 941.

IS 941: Marking and Labelling Key Points

• Clause 9.1.1:
  The product may be marked with the Standard Mark to indicate conformity to IS 941.

• Clause 9.1.2:
  Use of the Standard Mark is regulated by the Bureau of Indian Standards Act, 1986.
  Manufacturers must obtain a licence from BIS to use this mark legally.

Important Notes:

• The Standard Mark ensures product compliance and quality assurance.
• Specific details on licensing and conditions are available from the Bureau of Indian Standards directly.
• No explicit formulas or tables are provided in IS 941 for marking; it focuses on regulatory compliance.

Summary Table:

flowchart TD
    A[Manufacturer] --> B[Apply for BIS License]
    B --> C{License Granted?}
    C -- Yes --> D[Use Standard Mark on Product]
    C -- No --> E[No Marking Allowed]
    D --> F[Product Sold with BIS Mark]

For detailed licensing conditions, contact BIS or visit their official website.

IS 941 Painting & Finishing Key Points:

• Primer: One coat of red oxide primer is mandatory.
• Top Coats: Two coats of paint after primer.
• Paint Shades:
  • Stand body: Black.
  • Fire red: Shade No. 536 as per IS:5-1978 (Specification for colours for ready mixed paints and enamels).
• Paint Standard: Paints must conform to IS:2932-1974 (Specification for paints for general engineering purposes).

Summary Table for Painting

This ensures corrosion protection and standardized color coding for safety and identification.

flowchart TD
    A[Surface Preparation] --> B[Apply 1 Coat Red Oxide Primer]
    B --> C[Apply 1st Coat Paint (Black/Fire Red)]
    C --> D[Apply 2nd Coat Paint (Black/Fire Red)]
    D --> E[Finished Surface]

For detailed paint types and application methods, refer to IS:2932-1974 and IS:5-1978.

IS 941 - Criteria for Conformity (Clause 10)

• Scope: Each firefighting equipment must be checked against all requirements specified in IS 941.
• Conformity Checks: Include dimensional, material, performance, and safety tests as per relevant clauses.
• Standard Mark Usage: Governed by BIS Act 1986; license conditions available from BIS.

Key Points for Conformity:

Typical Formula for Flow Rate Verification:

[ Q = A \times v ]

Where:

• (Q) = Flow rate (liters/min)
• (A) = Cross-sectional area of nozzle (cm²)
• (v) = Velocity of water (cm/s)

Summary Diagram:

flowchart TD
    A[Start: Equipment Sample] --> B{Check Dimensions}
    B -- Pass --> C{Material Quality}
    B -- Fail --> Z[Reject]
    C -- Pass --> D{Performance Tests}
    C -- Fail --> Z
    D -- Pass --> E{Safety Compliance}
    D -- Fail --> Z
    E -- Pass --> Y[Conformity Achieved]
    E -- Fail --> Z

Note: For detailed test procedures and limits, refer to the full IS 941 standard or contact BIS offices listed in the document.

IS 941: Packaging and Handling Key Points

• Engine Packaging: Petrol engine (2.5 kW) with a 3-litre petrol tank must be securely packed with a frame equipped with lifting handles for safe handling.

• Materials for Packaging:

  • Frame: Mild steel tubes as per IS 1239 (Part 1)-1979.
  • Wire fabric: Welded steel wire fabric conforming to IS 4948-1974.
  • Canvas: Cotton canvas for protective covering (second revision specification).

• Handling Requirements:

  • The frame must allow lifting and transportation without damage.
  • Packaging must protect the engine against mechanical shocks and environmental effects during transit.

• Conformity Check:

  • Clause 10.1 mandates inspection against packaging and handling criteria to ensure compliance.

Typical Packaging Frame Specification (Example)

Handling Tips

• Use lifting handles on the frame.
• Avoid direct impact on petrol tank.
• Ensure secure fastening inside packaging to prevent movement.

flowchart LR
    A[Engine with Petrol Tank] --> B[Frame with Lifting Handles]
    B --> C[Wire Fabric Protection]
    C --> D[Cotton Canvas Covering]
    D --> E[Safe Handling & Transport]

This ensures compliance with IS 941 packaging and handling standards for petrol engines.

IS 941: Key Annexes, Notes, and Specifications Summary

1. Material Specifications (Clause 3.1, Table 1)

2. Engine Options (Amendment No. 2, March 1993)

• Petrol Engine: 2.5 kW capacity with 3-litre petrol tank (IS 7347:1974)
• Lightweight Diesel Engine: 3.23 kW capacity (IS 10001:1981)
• Electric Motor Alternative: 3-phase induction motor, 2.2 kW (IS 325:1978), optionally flameproof (IS 2148:1981)

3. Notes on Electric Supply (Clause 2.2)

• Where electric supply is feasible, replace petrol engine with a 3-phase induction motor of 2.2 kW capacity.
• Flameproof enclosures are recommended for hazardous environments.

4. Conformity Criteria (Clause 10.1)

• All equipment must comply with the material and performance requirements as per IS 941.
• Testing and inspection are mandatory for certification.

Visual Summary: Material and Power Options

graph TD
    A[Blower & Exhauster Components] --> B[Impeller: Aluminium Grade 4423]
    A --> C[Casing: Aluminium Grade 4423]
    A --> D[Suction Mouth: Aluminium Grade 4423]
    A --> E[Exhaust Pipe: Canvas]
    A --> F[Frame: