I. Common Types and Characteristics
- Characteristics: Nozzle faces upward, deflector is below the sprinkler head; water sprays upward and then spreads downward.
- Applications: Installed in environments without ceilings or exposed pipes (e.g., warehouses, workshops).
2. Pendant Sprinkler/Downward Sprinkler
- Characteristics: Nozzle faces downward, deflector is above the sprinkler head; water sprays directly downward.
- Applications: Ceilinged spaces (e.g., offices, hotels) where pipes are concealed.
3. Standard/Universal Sprinkler
- Characteristics: Can be installed upward or downward; deflector adapts to multiple orientations.
- Applications: Areas with no specific installation direction requirements.
4. Sidewall Sprinkler
- Characteristics: Horizontally mounted on walls; water sprays in a parabolic pattern to cover one side.
- Applications: Corridors, narrow spaces, or areas where central installation is impractical.
5. Concealed Sprinkler
- Characteristics: Equipped with a decorative cover that drops during a fire to activate water discharge.
- Applications: Aestheticfocused spaces (e.g., malls, hotels), though response time is slightly slower.
6. Quick Response (QR) Sprinkler
- Characteristics: Highsensitivity thermal element for faster activation compared to standard models.
- Applications: Residential buildings, hospitals, and other spaces requiring rapid fire control.
7. ESFR Sprinkler (Early Suppression Fast Response)
- Characteristics: Highvolume water discharge designed to suppress fires quickly.
- Applications: Highfireload environments (e.g., highrack warehouses).
8. Dry Sprinkler
- Characteristics: Sealed and waterfree internally; activates when the thermal element ruptures, allowing water flow.
- Applications: Lowtemperature environments (e.g., cold storage) to prevent pipe freezing.
II. Differentiation Methods
1. Appearance and Installation Orientation
- Upright: Nozzle upward, deflector below.
- Pendant: Nozzle downward, deflector above.
- Sidewall: Flat design, horizontal wall mounting.
- Concealed: Hidden behind a decorative cover.
2. Temperature Rating Identification
- Colorcoded thermal elements: Orange (57°C), Red (68°C), Yellow (79°C), Green (93°C), Blue (141°C).
3. Response Time
- Standard Response: RTI ≥ 80.
- Quick Response: RTI ≤ 50, labeled “QR”.
- ESFR: Combines fast response with high flow rates.
4. Application Scenarios
- Select based on environment: ESFR for warehouses, dry sprinklers for cold storage.
III. Relevant Standards
1. International Standards
- NFPA 13 (U.S.): Covers design, installation, and testing of sprinkler systems; basis for ESFR design.
2. Chinese Standards
- GB 5135.12019: Specifies performance, testing, and labeling of sprinklers.
- GB 500842017: Guidelines for system design and selection.
- GB 502612017: Regulations for construction and acceptance.
3. Other Standards
- UL 199 (U.S.): Certifies safety and reliability.
- EN 12259 (EU): Similar to NFPA for European countries.
IV. Key Considerations
- Selection Criteria: Evaluate building structure, temperature, and fire risks.
- Maintenance: Regularly check for blockages, corrosion, and thermal element functionality.
- Installation: Follow spacing standards to avoid coverage obstructions.
Explanation of Sprinkler KFactor
Kfactor (flow coefficient) is a critical parameter defining a sprinkler’s water discharge capacity under specific pressure.
I. Definition and Formula
Formula:
Q = K \times \sqrt{P}
Q : Flow rate (L/min or GPM).
K : Kfactor.
P : Pressure at sprinkler inlet (MPa or bar).
II. KFactor Categories
| KFactor Range | Common Values | Applications |
||||
| Low Flow | K=50, 57, 80 | Offices, hotel rooms |
| Medium Flow | K=115, 160 | Malls, hospitals |
| High Flow | K=202, 242, 363 | Warehouses, logistics centers |
| UltraHigh Flow | K=360+ (ESFR) | Highrack storage |
III. Regional Standards
1. China (GB 5135.12019): Metric units (e.g., K=80 = 80 L/min at 0.1 MPa).
2. U.S. (NFPA 13): Imperial units (K=5.6 ≈ K=80 metric).
3. Europe (EN 12259): Metricaligned with localized testing.
IV. Selection Guidelines
PressureFlow Matching: Calculate required Kfactor based on fire risk, area, and pressure.
Risks of Incorrect Selection:
- Undersized K: Inadequate flow.
- Oversized K: Pressure loss and uneven coverage.
V. Maintenance and Labeling
- Labeling: Kfactor engraved on sprinkler (e.g., “K80”).
- Replacement: Avoid mixing Kfactors to prevent hydraulic imbalance.
- Testing: Ensure flow rates meet specifications.
VI. Key Standards
- GB 5135.12019 (China): Testing and performance requirements.
- NFPA 13 (U.S.): Kfactor classifications and ESFR criteria.