Q = (29.83)(c)(d)2(P)
Where:
Q = GPM
c = Orifice Coefficient (rounded = .9; square = .8; projected = .7)
D = Orifice Diameter
P = Pitot Reading
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Thursday, April 12, 2012
Wednesday, April 11, 2012
Seven Common Fire Sprinkler Design and Layout Mistakes:
1.Not using the available water supply curve to its fullest resulting in oversized piping.
2.Calculating the system for xyz sq. ft. per sprinkler and then over-spacing other sprinklers without regard for calculated area.
3.Placing sprinklers too far away from walls and obstructions resulting in over-spaced sprinklers.
4.Ignoring obstructions resulting in too few sprinklers.
5.Not using obstruction rules properly resulting in too many sprinklers.
6.Seismic bracing improperly sized, attached to structure incorrectly, and spaced without regard to the zone of influence.
7.The wrong sprinkler used in the wrong situation resulting in poor design and your dollars wasted.
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2.Calculating the system for xyz sq. ft. per sprinkler and then over-spacing other sprinklers without regard for calculated area.
3.Placing sprinklers too far away from walls and obstructions resulting in over-spaced sprinklers.
4.Ignoring obstructions resulting in too few sprinklers.
5.Not using obstruction rules properly resulting in too many sprinklers.
6.Seismic bracing improperly sized, attached to structure incorrectly, and spaced without regard to the zone of influence.
7.The wrong sprinkler used in the wrong situation resulting in poor design and your dollars wasted.
www.firebyknight.com
Tuesday, April 3, 2012
Protection Areas Per Sprinkler - S X L
To determine the coverage along the branch line you choose the distance between sprinklers or the distance to the wall or obstruction for the end sprinkler. Then you use the distance between sprinklers or twice the distance to the wall, which ever is greater. The distance along the branch line is then defined as S.
To determine the coverage between branch lines you choose the distance between branch lines or the distance to the wall or obstruction to the side of the branch line. Then you use the distance between branch lines or twice the distance to the wall, which ever is greater. The distance between the branch lines is then defined as L.
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To determine the coverage between branch lines you choose the distance between branch lines or the distance to the wall or obstruction to the side of the branch line. Then you use the distance between branch lines or twice the distance to the wall, which ever is greater. The distance between the branch lines is then defined as L.
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Friday, March 30, 2012
Scaling objects in a CAD environment
While performing fire sprinkler design or fire sprinkler layout it is often necessary to scale an object or group of objects. The following information can be used to help with this process.
SCALING:
To scale an object up –
Divide little number by big number
To scale an object down –
Divide big number by little number
Paper Space Scaling –
Divide bottom number by top number then multiply by 12.
i.e. 1/8th scale
8/1 * 12 = 96
Site Plan Scale – (Assumes 1/8th scale as default)
Scale:
Scale by:
1/10 1.25
1/16 2
1/20 2.5
1/30 3.75
1/40 5
1/50 6.25
1/60 7.5
1/100 12.5
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SCALING:
To scale an object up –
Divide little number by big number
To scale an object down –
Divide big number by little number
Paper Space Scaling –
Divide bottom number by top number then multiply by 12.
i.e. 1/8th scale
8/1 * 12 = 96
Site Plan Scale – (Assumes 1/8th scale as default)
Scale:
Scale by:
1/10 1.25
1/16 2
1/20 2.5
1/30 3.75
1/40 5
1/50 6.25
1/60 7.5
1/100 12.5
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Thursday, March 29, 2012
Fire Sprinkler Design info for Air Compressors
How To Size An Air Compressor:
To size air compressor multiply system volume x .012.
Example: 550 gal. * .012 = 6.6 CFM.
or
CFM = (SYS VOL x 40) / (30 x 7.48 x 15)
How to determine time to fill system with air:
Convert gallons to cubic feet – 1 gallon = .13368 f3
Divide system cubic feet by compressor CFM
Example: 550 * .13368 = 73.53 f3
73.53 / 6.6 = 11.14 minutes to fill system
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To size air compressor multiply system volume x .012.
Example: 550 gal. * .012 = 6.6 CFM.
or
CFM = (SYS VOL x 40) / (30 x 7.48 x 15)
How to determine time to fill system with air:
Convert gallons to cubic feet – 1 gallon = .13368 f3
Divide system cubic feet by compressor CFM
Example: 550 * .13368 = 73.53 f3
73.53 / 6.6 = 11.14 minutes to fill system
www.firebyknight.com
Wednesday, March 28, 2012
WET-PIPE PROCEDURES Part 4
A. Startup:
1. Close main drain valve. Leave auxiliary drain valves, or other vent connections open.
2. Open the ¼” gauge test valves for the supply and system pressure gauges.
3. Slowly open main control valve until the sound of flowing water just starts, then open the valve one more turn.
4. Observe auxiliary drain valves and close after a solid flow of water (not aerated), has continued for at least 15 seconds.
5. Fully open main control valve.
6. Reset Tamper Alarm.
7. Verify stabilization of supply and system pressure gauges.
8. Verify that the water ceased to flow from alarm drain line.
The above information is provided as a courtesy and is not intended to replace the outlined procedures as given in NFPA 24. It is the owner’s responsibility to follow the outlined procedures in NFPA 24.
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1. Close main drain valve. Leave auxiliary drain valves, or other vent connections open.
2. Open the ¼” gauge test valves for the supply and system pressure gauges.
3. Slowly open main control valve until the sound of flowing water just starts, then open the valve one more turn.
4. Observe auxiliary drain valves and close after a solid flow of water (not aerated), has continued for at least 15 seconds.
5. Fully open main control valve.
6. Reset Tamper Alarm.
7. Verify stabilization of supply and system pressure gauges.
8. Verify that the water ceased to flow from alarm drain line.
The above information is provided as a courtesy and is not intended to replace the outlined procedures as given in NFPA 24. It is the owner’s responsibility to follow the outlined procedures in NFPA 24.
www.firebyknight.com
Tuesday, March 27, 2012
WET-PIPE PROCEDURES Part 3
III. SYSTEM SHUTDOWN & STARTUP:
A. Shutdown
A. Close main control valve.
B. Silences tamper alarm.
C. Open main and auxiliary drains to drain system piping if repair work or sprinkler replacement is required.
NOTE: Wait until the sound of draining water has stopped and/or the inlet and outlet pressure gauges read zero pressure, before performing and maintenance work.
The above information is provided as a courtesy and is not intended to replace the outlined procedures as given in NFPA 24. It is the owner’s responsibility to follow the outlined procedures in NFPA 24.
www.firebyknight.com
A. Shutdown
A. Close main control valve.
B. Silences tamper alarm.
C. Open main and auxiliary drains to drain system piping if repair work or sprinkler replacement is required.
NOTE: Wait until the sound of draining water has stopped and/or the inlet and outlet pressure gauges read zero pressure, before performing and maintenance work.
The above information is provided as a courtesy and is not intended to replace the outlined procedures as given in NFPA 24. It is the owner’s responsibility to follow the outlined procedures in NFPA 24.
www.firebyknight.com
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