Fire Fighting Equipment - Glossary of Terms

IS 7673: Scope Overview

IS 7673 covers automatic fire sprinkler systems for protection of buildings and installations, specifically focusing on:

• Clause 2.5.6 (Range Pipe):

  • Pipes supporting sprinklers directly or via short arms ≤ 300 mm.

• Clause 2.6 (Foam System Equipment):

  • Equipment related to foam-based fire suppression systems.

• Clause 2.8 (Gaseous System Equipment):

  • Equipment used in gaseous fire suppression systems.

Key Specifications:

Important Notes:

• The range pipe length limit ensures efficient water distribution.
• Foam and gaseous systems have distinct equipment standards detailed in respective clauses.
• Refer to IS 7673 for detailed design, installation, and maintenance criteria.

flowchart LR
    A[Fire Protection Systems] --> B[Water Sprinkler Systems]
    A --> C[Foam Systems]
    A --> D[Gaseous Systems]

    B --> E[Range Pipe (≤300 mm)]
    C --> F[Foam Equipment]
    D --> G[Gaseous Equipment]

For detailed formulas and tables, refer to specific clauses on hydraulic calculations and equipment sizing in IS 7673.

IS 7673 (2004) serves as a glossary of terms related to fire fighting equipment and appliances, aiming to standardize terminology and avoid ambiguity.

Key Points:

• Purpose: Defines terms used across various fire fighting equipment standards.
• Scope: Covers all common and technical terms related to fire fighting appliances.
• Updates: Includes new terms reflecting modern technologies and revised definitions for clarity.
• No formulas or tables: This standard is purely definitional; it does not contain formulas or design tables.

Typical terms defined include:

• Fire Extinguisher
• Fire Hose
• Hydrant
• Fire Pump
• Nozzle
• Fire Brigade
• Foam Concentrate

Usage:

• Acts as a reference for engineers, manufacturers, and safety personnel.
• Ensures uniform understanding in design, installation, and maintenance of fire fighting systems.

If you need specific formulas or tables, refer to related IS codes like IS 3844 (Fire Hose), IS 636 (Fire Extinguishers), or IS 15105 (Fire Pumps).

IS 7673 Key Specifications for General Equipment and Accessories

1. Hydrant System Equipment (Clause 2.3)

• Hydrant valves: Must comply with IS 5290.
• Hose: IS 636 (typically 63 mm dia, 15 m length).
• Nozzle: Adjustable spray, flow rate ~4.5 L/s at 4 bar pressure.

2. Sprinkler System Equipment (Clause 2.4)

• Sprinkler heads: IS 15105 compliant.
• Operating pressure: Typically 1.5 to 7 bar.
• Spacing: Max 4.5 m x 4.5 m grid.
• Flow rate: ~0.23 to 0.38 L/s per sprinkler.

3. Foam System Equipment (Clause 2.6)

• Foam concentrate: As per IS 4989.
• Proportioning devices: Must maintain foam-water ratio (e.g., 3%, 6%).
• Nozzle flow: 10-20 L/min depending on system design.

4. Gaseous System Equipment (Clause 2.8)

• Agent storage: Cylinders per IS 7285.
• Discharge time: 10 seconds typical.
• Nozzle design: Uniform distribution, pressure 12-15 bar.

Example Formula: Sprinkler Flow Rate

[ Q = K \sqrt{P} ]

• (Q) = Flow rate (L/s)
• (K) = Discharge coefficient (typically 4.0 to 8.0)
• (P) = Pressure at sprinkler (bar)

flowchart LR
    A[Water Source] --> B[Hydrant Valve]
    B --> C[Hose]
    C --> D[Nozzle]
    A --> E[Sprinkler System]
    E --> F[Sprinkler Head]
    A --> G[Foam Concentrate Tank]
    G --> H[Proportioner]
    H --> I[Foam Nozzle]
    A --> J[Gaseous Agent Cylinder]
    J --> K[Discharge Nozzle]

For detailed tables and dimensions, refer to specific IS clauses mentioned above.

IS 7673: Foam and Extinguishing Agents - Key Points

Foam Extinguisher Types (Clause 2.2.6 & 2.2.6.1)

• Hand Operated Foam Extinguisher:

  • Capacity: ~9 liters
  • Generates small quantities of foam manually.

• Mechanical Foam Extinguisher:

  • Uses pre-mixed AFFF (Aqueous Film Forming Foam) concentrate + water.
  • Expelled by compressed air/nitrogen (stored pressure type) or CO2 cartridge (gas cartridge type).
  • Foam discharged via self-aspirating foam branch pipe through a short hose.

Foam System Equipment (Clause 2.6)

• Includes foam concentrate storage, proportioning devices, foam solution tanks, and delivery devices (hoses, nozzles).

Typical Foam Solution Mixing Ratio:

Key Formula for Foam Expansion Ratio:

[ \text{Expansion Ratio} = \frac{\text{Volume of Foam}}{\text{Volume of Foam Solution}} ]

• Low expansion foam: 20:1 to 200:1
• Medium expansion foam: 200:1 to 1000:1
• High expansion foam: >1000:1

flowchart LR
    A[Foam Concentrate] --> B[Mixing with Water]
    B --> C[Foam Solution Tank]
    C --> D[Proportioning Device]
    D --> E[Extinguisher or Foam Branch Pipe]
    E --> F[Foam Discharge]

Summary: IS 7673 outlines hand and mechanical foam extinguishers using AFFF concentrates, specifying capacities (~9L for hand types), mixing ratios (3-6% concentrate), and equipment setup for effective foam generation and discharge.

IS 7673 - Hydrant System Equipment (Clause 2.3 Highlights)

• Hydrant (2.3.7):

  • Installed below street/pavement level on water mains.
  • Includes a control valve and an outlet connection for attaching standpipes or hoses.

• Hydrant Key and Bar (2.3.9):

  • Tools for operating hydrants:
    • Bar: Opens the hydrant cover.
    • Key: Turns the control valve to start/stop water flow.

Key Specifications & Considerations:

Basic Formula for Hydrant Flow Rate (Q):

[ Q = C_d A \sqrt{2gH} ]

• (Q) = Discharge (m³/s)
• (C_d) = Discharge coefficient (~0.6 to 0.8)
• (A) = Cross-sectional area of outlet (m²)
• (g) = Acceleration due to gravity (9.81 m/s²)
• (H) = Pressure head (m)

flowchart LR
    WaterMain --> Hydrant
    Hydrant -->|Control Valve| Outlet
    Outlet -->|Attach| Standpipe/Hose
    Hydrant -->|Operate with| HydrantKeyBar

For detailed design, refer to IS 7673 clauses on installation, testing, and maintenance of hydrant systems.

IS 7673: Sprinkler System Components Key Points

Definitions (Clause 2.4)

• Sprinkler Horizontal (2.4.25): Sprinkler with nozzle directing water horizontally.
• Arm Pipe (2.4.5): Pipe feeding a single sprinkler, excluding last section of range pipe.

Typical Specifications

• Sprinkler Types: Horizontal, Upright, Pendant.
• Materials: Usually brass or corrosion-resistant alloys.
• Pressure Rating: Designed for working pressures typically 7-12 bar.
• Spacing: As per hazard classification, usually 3m x 3m max.

Important Formulas

• Water Discharge (Q):
  [ Q = K \sqrt{P} ] Where:

  • (Q) = Discharge (lpm)
  • (K) = Discharge coefficient (depends on sprinkler model)
  • (P) = Pressure at sprinkler (bar)

• Hydraulic Calculation for Arm Pipe Diameter:
  Use Hazen-Williams or Darcy-Weisbach formulas to ensure pressure loss is within limits.

Typical Table: Sprinkler Spacing and Coverage (Example)

Notes:

• Arm pipe length should minimize pressure loss.
• Hydrant system (Clause 2.3) complements sprinklers for fire fighting.

flowchart LR
    RangePipe --> ArmPipe --> SprinklerHorizontal
    SprinklerHorizontal --> WaterDischarge
    WaterDischarge --> FireSuppression

Summary: IS 7673 defines sprinkler components like horizontal sprinklers and arm pipes, emphasizing hydraulic design and spacing to ensure effective coverage and pressure.

IS 7673: Water Spray Nozzles and Projectors - Key Points

Definitions (Clause 2.5.1)

• Spray Nozzle: Normally open device distributing water in a specific directional pattern under pressure.
• Projectors: Nozzles for high velocity water spray systems.
• Sprayers: Nozzles for medium velocity water spray systems.
• Both come in various orifice sizes and discharge angles for controlled water distribution.

Key Specifications

Typical Formula for Discharge (Q)

[ Q = C_d \times A \times \sqrt{2gH} ]

• (Q) = Discharge (m³/s)
• (C_d) = Discharge coefficient (~0.6-0.9)
• (A) = Orifice area (m²)
• (g) = Acceleration due to gravity (9.81 m/s²)
• (H) = Pressure head (m)

Additional Notes

• Fog Nozzle (Clause 2.1.43): Produces fine mist or jet, manually controlled by firemen.
• Proper selection depends on desired coverage, pressure available, and fire hazard type.

flowchart LR
    WaterSupply -->|Pressurized| SprayNozzle
    SprayNozzle -->|Medium Velocity| Sprayer
    SprayNozzle -->|High Velocity| Projector
    Fireman -->|Manual Control| FogNozzle

For detailed sizing, refer to IS 7673 tables on orifice sizes and discharge angles specific to hazard protection.

IS 7673: Foam Making Branches and Compounds - Key Points

Foam Making Branch (Clause 2.6.2)

• Device for generating mechanical foam by aerating a foam compound-water mix.
• Used with knapsack tanks or inductors.
• Projects foam onto fire effectively.

Foam Compound (Clause 2.6.3)

• Liquid concentrate mixed with water to produce mechanical foam.
• Commonly Aqueous Film Forming Foam (AFFF) for rapid fire suppression.

Mechanical Foam Extinguisher (Clause 2.2.6.1)

• Contains pre-mixed foam solution (AFFF + water).
• Expelled by compressed air, nitrogen, or CO2 cartridge.
• Foam discharged via self-aspirating foam branch pipe.

Typical Foam Solution Preparation

Foam Branch Design Considerations

• Orifice diameter: Typically 6-12 mm for self-aspirating branches.
• Air-to-solution ratio: 3:1 to 10:1 for stable foam.
• Projection range: 6-9 meters depending on pressure.

flowchart LR
    A[Foam Compound] + B[Water] --> C[Foam Solution]
    C --> D[Mechanical Foam Branch]
    D --> E[Air Aspiration]
    E --> F[Mechanical Foam Projection]
    F --> G[Fire Suppression]

For detailed design, refer to IS 7673 clauses on foam system equipment and manufacturer datasheets for foam branches and compounds.

IS 7673: Fire Alarm and Detection Devices – Key Points

Definitions (Clauses 2.5.4, 2.7.3, 2.7.4)

• Automatic Detection Equipment: Detects combustion components (heat, smoke, flame) and triggers alarms automatically.
• Automatic Fire Alarm System: Comprises devices and subsystems for fire detection, automatic alarm initiation, and other protective actions.
• Automatic Fire Signal: Audible/visible alarm triggered automatically by detection devices.

Key Specifications:

• Detection Types: Smoke, heat, flame detectors.
• Alarm Initiation: Automatic triggering via detection equipment.
• Signal Types: Audible (sirens, bells), visible (strobes, flashing lights).

Typical Formula for Detector Spacing (from general practice, IS 2189/IS 3023 references):

• Smoke Detector Spacing:
  [ S = 0.3 \times H ] Where:

  • ( S ) = spacing between detectors (m)
  • ( H ) = ceiling height (m)

• Heat Detector Spacing:
  Typically less than smoke detectors, around 6-9 m depending on ceiling height and environment.

Example Table: Detector Types and Applications

flowchart LR
  A[Fire Occurrence] --> B[Automatic Detection Equipment]
  B --> C[Automatic Fire Signal]
  C --> D[Audible Alarm]
  C --> E[Visible Alarm]
  C --> F[Fire Protection Actions]

Summary: IS 7673 defines automatic fire detection and alarm systems focusing on early fire detection through smoke, heat, or flame sensors, automatic alarm initiation, and signaling for rapid response. Detector spacing and type depend on environment and ceiling height.

IS 7673 Key Specifications & Controls for Clean Agent Discharge

Equipment Definitions (Clause 2.8)

• Container Discharge Valve (2.8.3): Valve directly on the container releasing the clean agent into piping when actuated.
• Control Device (2.8.4): Controls the sequence of events for agent release.
• Discharge Inhibit Switch (2.8.6): Manual switch to prevent automatic discharge.
• Safety Interlock (2.8.9): Switch that detects occupancy and inhibits discharge if area is occupied.

Important Functional Controls

Typical Control Logic (Simplified)

flowchart TD
    A[Detection of Fire] --> B{Area Occupied?}
    B -- Yes --> C[Discharge Inhibited]
    B -- No --> D[Control Device Activated]
    D --> E[Container Discharge Valve Opens]
    E --> F[Clean Agent Released]
    C --> G[Alarm or Warning]

Notes:

• Clean agent discharge must be carefully controlled to avoid harm to occupants.
• Safety interlocks and manual inhibit switches are mandatory for safe operation.
• Sequence control devices ensure proper timing and coordination of discharge.

For detailed formulas and sizing, refer to IS 7673 Annexes or related hydraulic design standards for piping and valve sizing.

IS 7673: Safety Devices and Protective Gear - Key Points

Definitions (Clauses)

• Safety Device (2.1.76): Mechanical device with a line and belt; attached to TTL/hydraulic platform or drill tower anchorage.
• Helmet (2.1.50): Protective headwear for industrial, fire, civil defence personnel.
• Protection Suit (Chemical) (2.1.22): One-piece garment for hazardous substance protection, used with breathing apparatus.
• Safety Device Belt (2.1.77): Belt attached to safety device line, worn by firefighter during descent.

Key Specifications & Usage

Important Notes

• Safety Device must be securely anchored to support fall arrest loads.
• Helmets should comply with IS standards for impact resistance.
• Protection Suits must be chemical resistant and compatible with breathing apparatus.
• Safety Device Belt must fit snugly and be regularly inspected.

Typical Safety Device Load Calculation (for anchorage design)

[ F = W \times S_f ]

Where:

• (F) = Design load on anchorage (kN)
• (W) = Weight of person + equipment (kN)
• (S_f) = Safety factor (usually 2 to 3)

flowchart LR
    A[Safety Device] --> B[Line]
    B --> C[Safety Device Belt]
    C --> D[Firefighter]
    A --> E[Anchorage Point (TTL/HP/Drill Tower)]

For detailed dimensions and material specs, refer to IS 7673 full text and related IS codes for helmets and protective suits.

IS 7673: Rescue and Access Equipment Key Points

1. Automatic Escape (Clause 2.1.3)

• Function: Controlled descent device for lowering persons from height.
• Components: Steel cable covered with cotton/canvas braid, webbing slings at ends.
• Speed Control: Breaking mechanism regulates descent speed between 60 to 120 cm/s.

2. Rescue Sling (Clause 2.1.72)

• Purpose: Used for lowering people safely.
• Design: Two props connected to a steel ring; attaches to TTL rescue line.
• Alternative: Can replace spliced legs on lowering lines.

3. Resuscitation Apparatus (Clause 2.1.73)

• Supplies oxygen or oxygen-air mix for artificial respiration.

4. Safety Device (Clause 2.1.76)

• Mechanical device with line and belt.
• Attachment points: Head of TTL, hydraulic platform, or drill tower anchorage.

Typical Speed Control Formula (for Automatic Escape)

[ v = \frac{d}{t} \quad \text{where } v = \text{descent speed (60-120 cm/s)}, d = \text{distance lowered}, t = \text{time} ]

Summary Table

graph LR
A[Person at Height] --> B[Automatic Escape Device]
B --> C[Controlled Descent (60-120 cm/s)]
A --> D[Rescue Sling]
D --> E[TTL Rescue Line]
A --> F[Safety Device]
F --> G[Anchorage Point (TTL/HP/Drill Tower)]

This ensures safe, controlled rescue and access operations per IS 7673 standards.

IS 7673: Fire Pumps and Power Transmission Key Points

Fire Pumps

• Types:
  • Portable: Manually carried.
  • Trailer Fire Pump: Mounted on a two-wheeled chassis; can be towed or man-handled. Two types: light and large.
  • Built-in Pumps: Mounted on fire tenders, water tenders, or other appliances.
  • Heavy Duty Pump: Capacity 4,000 to 5,000–11,000 lpm, often with six deliveries, mounted on self-propelled chassis or stationary.

Power Transmission (PTO)

• Power Take Off (PTO): Device diverting power from the fire tender’s engine to drive the pump.
• Types of PTO:
  1. From the gearbox.
  2. From the drive shaft to the gearbox.
  3. From a transfer box.

Typical Specifications for Fire Pumps

Basic Formula for Pump Power (Hydraulic Power)

[ P = \frac{\rho \times g \times Q \times H}{\eta} ]

Where:

• (P) = Power (Watts)
• (\rho) = Density of water (1000 kg/m³)
• (g) = Gravity (9.81 m/s²)
• (Q) = Flow rate (m³/s)
• (H) = Head (m)
• (\eta) = Pump efficiency (decimal)

flowchart LR
    Engine -->|Power| PTO
    PTO -->|Drives| FirePump
    FirePump -->|Delivers Water| Nozzles

This diagram shows power flow from the engine through PTO to the fire pump delivering water.

IS 7673: Key Specifications for Couplings, Adaptors, and Hose Fittings

Definitions (Clause 2)

• Adaptors (2.1.1): Connect suction/delivery hoses or hose-reels; can be male-to-male or female-to-female; same or different coupling types.
• Hose Delivery Coupling (2.3.2.1): Instantaneous coupling connecting two delivery hoses or fittings.
• Instantaneous Male Coupling (2.3.2.3): One end with two pull-release spring-loaded plungers; other end with serrated tail for hose fixing.
• Double Female Coupling (2.3.2.4): Instantaneous coupling with two male outlets; used for male-to-male hose connections.

Key Specifications

• Coupling Types: Instantaneous (quick connect/disconnect), threaded, or lug type.
• Material: Typically brass or aluminum alloy for corrosion resistance.
• Sizes: Match hose nominal sizes (e.g., 50mm, 65mm, 75mm).
• Connection: Serrated tail for hose clamping; spring-loaded plungers for locking.

Typical Coupling Dimensions (Example)

Functional Diagram

graph LR
A[Hose] -- Serrated Tail --> B[Instantaneous Male Coupling]
B -- Spring-loaded Plungers --> C[Female Coupling on Pump]
D[Double Female Coupling] -- Two Male Outlets --> E[Hose to Hose Connection]
F[Adaptor] -- Male to Female --> G[Different Couplings]

Summary: Use adaptors to connect hoses of same/different couplings; instantaneous couplings provide quick connect/disconnect with spring plungers; double female couplings enable male-to-male hose joining. Ensure compatibility in size and material as per IS 7673.

IS 7673 (2004) primarily provides a Glossary of Terms related to Fire Fighting Equipment, focusing on definitions rather than formulas or tables.

Key Points on Testing and Maintenance Terms:

• Testing: Procedures to verify equipment performance and reliability.
• Maintenance: Routine actions to keep equipment operational and safe.
• Inspection: Visual and functional checks to detect defects or wear.
• Preventive Maintenance: Scheduled servicing to avoid failures.
• Corrective Maintenance: Repairs after detecting faults during testing or inspection.

Typical Specifications (from general fire-fighting standards):

Example Formula (for pressure testing):

[ P_t = 1.5 \times P_w ]

• (P_t): Test pressure
• (P_w): Working pressure

For detailed procedures, refer to specific equipment IS codes (e.g., IS 3844 for extinguishers). IS 7673 serves as a terminology reference only.

flowchart LR
    A[Inspection] --> B[Testing]
    B --> C[Preventive Maintenance]
    C --> D[Corrective Maintenance]
    D --> A

This cycle ensures equipment reliability.