The sprinkler system is very important for building fire protection, household irrigation or industrial cooling. The size of the sprinkler pipe is also crucial. If the size is incorrect, it will directly affect the efficiency, safety and stability of the entire sprinkler system.
Why Size Matters
If the size is small, the water flow will be fast, and the pressure loss will be large and water cannot be sprayed. If the size is large, the cost and difficulty of installation will increase significantly. So the size is not the bigger the better, and the smaller the size, the more money it will save.
It is necessary to make a comprehensive assessment from three aspects: flow rate, pressure and cost. According to Bernoulli’s Equation, the speed of water flow in the pipeline is inversely proportional to the diameter of the pipe – the larger the diameter of the pipe, the slower the flow rate and the smaller the pressure loss.
Sprinkler Pipe Size Chart
Fire sprinkler system size chart (ASTM A53 Type E Grade B)
|
Pipe diameter (DN) |
Inch |
Outer diameter , mm |
Schedule 40, mm |
Maximum number of nozzles |
Maximum flow rate (L/min) |
|
DN25 |
1 |
33.7 |
3.2 |
4 |
60 |
|
DN32 |
1.25 |
42.4 |
3.5 |
8 |
120 |
|
DN40 |
1.5 |
48.3 |
3.6 |
12 |
180 |
|
DN50 |
2 |
60.3 |
3.9 |
16 |
240 |
|
DN65 |
2.5 |
76.1 |
4.1 |
24 |
360 |
|
DN80 |
3 |
88.9 |
4.2 |
32 |
480 |
|
DN100 |
4 |
114.3 |
4.5 |
48 |
720 |
Domestic sprinkler (irrigation) system size chart (PVC-U pipe)
|
Pipe diameter (DN) |
Inch |
Outer diameter , mm |
Schedule 40, mm |
Maximum number of nozzles |
Maximum flow rate (L/min) |
|
DN15 |
0.5 |
20 |
2.0 |
2 |
30 |
|
DN20 |
0.75 |
25 |
2.3 |
4 |
60 |
|
DN25 |
1 |
32 |
2.9 |
6 |
90 |
|
DN32 |
1.25 |
40 |
3.7 |
8 |
120 |
|
DN40 |
1.5 |
50 |
4.6 |
10 |
150 |
Industrial cooling system size chart (Stainless Steel 304 Pipes)
|
Pipe diameter (DN) |
Inch |
Outer diameter , mm |
Schedule 40, mm |
Maximum flow rate (m³/h) |
|
DN50 |
2 |
60.3 |
3.9 |
15 |
|
DN80 |
3 |
88.9 |
4.2 |
30 |
|
DN100 |
4 |
114.3 |
4.5 |
50 |
|
DN150 |
6 |
168.3 |
5.1 |
100 |
Sprinkler Pipe Size Chart: Standard
The following are the most commonly used standards
- GB 50084-2017 “Design Specifications for Automatic Sprinkler Fire Extinguishing Systems”: specifies the size requirements for consumer sprinkler pipes
The diameter of the pipe water distribution branch connected to the sprinkler head should not be less than DN25
The diameter of the pipe water distribution pipe connected to the branch should not be less than DN50
The diameter of the main pipeline trunk should not be less than DN100 (need to look at the total flow to calculate) - ASTM A53: The common model of the fire sprinkler system is Type E Grade B pipe, and the wall thickness meets the Schedule 40 for normal pressure or Schedule 80 for high pressure.
- ASME B36.10M: specifies the outer diameter and wall thickness
Factors affecting size
The following are the core factors that affect the size selection
- Building type: Commercial buildings require more nozzles and larger pipe diameters, while home buildings require fewer nozzles and smaller pipe diameters.
Number of nozzles: The greater the total flow demand, the more nozzles are needed, and the larger the pipe diameter needs to be. (The total flow of 10 10 L/min nozzles is 100 L/min, and a pipe with a DN of 32 or above needs to be selected.) - Inlet water pressure: Low water pressure requires a larger diameter pipe to reduce pressure damage.
- Media type: Corrosive liquids require corrosion-resistant pipes, and the pipe diameter needs to be recalculated; considering thermal expansion, a 10%-15% margin should be allowed.
