Transcript Automatic Sprinkler System - ministrytoolboxonline.com

Automatic Sprinkler System
Importance of Sprinklers
• First line of protection – small fires
• Enhanced protection
• Business protection – less interruption of business
operations
• Less loss
• Firefighter safety
Types of Sprinkler Systems
• Wet pipe
• Dry pipe
• Pre-action
• Deluge
Water Supply for Sprinklers
• Municipal
• Water tower
• Reservoir
• Pressure tank
• Fire department
Types of Control Valves
• Indicating valves – open or closed
•
Post Indicator Valve – P.I.V.
•
Outside Stern – Screw and Yolk -
•
O.S.& Y
•
Butterfly valve
•
Gate valve
•
Ball valve
Wet System
• Fire department connection - siamese
• Control Valves and Trim
• Alarm valve
• Check valve
Wet System
• Inspector’s test valve
• Water motor gongs
•
Gauges – street and system
•
Piping
•
Automatic sprinkler heads (closed) - Upright, pendent and sidewall
•
Operation
Dry Pipe System
• Fire Department connection – siamese
• Control valves and Trim
• Indicating valves - wall indicator, post indicator, OS&Y
• Dry pipe valve
• Check valve
•
Inspector’s valves
Dry system
•
Water motor
•
Gauges – air and water
•
Piping
•
Automatic sprinkler heads (closed) – upright, sidewalls and dry drop pendent
•
Compressors
•
Enclosures – heated
•
•
Gongs
Differential
• Differential dry-pipe alarm valves:
• 1. High Differential Valves (most common)
• The differential pressures in most of these valves are either a 5:1 or 6:1
ratio. In determining the amount of air pressure required to keep the valve
closed would be 1/6 or 1/5 that of the incoming water pressure from the
street main or other source of water.
• 6:1 Calculation:
• Street water pressure = 600 kPa
• Air pressure required = 600 divided by 6
• = 100 kPa (will hold the clapper valve closed.)
• It is customary to add some extra air pressure to prevent the valve from
tripping during pressure surges. The usual amount is 140 kPa.
• Therefore, for our calculations above the final answer would be:
• 100 + 140 kPa. = 240 kPa.
Differential
• 2. Low Differential Valves 1.1:1
• These valves use a much lower differential air pressure. A 1.1 to1
differential is most common. In other words the air pressure
required to hold the clapper closed will be 110% of the incoming
water pressure.
• See textbook for the advantages of these types of valves.
• General:
• Note that on a dry-pipe system much of the trim is located below
the clapper valve. The reason for this is to prevent air leaks. As well,
note that the clapper once opened is held open by a catch. This
facilitates draining the system after use. Unlike the wet pipe system,
the main drain on a dry pipe system is below the alarm valve.
Deluge System
• Fire Department Connection – siamese
• Control valves and Trim
• Indicating and pre-action
• Gauges – air and water
• Piping
Deluge System
• Automatic Sprinkler Heads (open) – upright and
sidewalls
• Automatic Detection Devices – electric and
pneumatic
• Operation
Pre-action System
• Fire department Connection – Siamese
• Control valves and trim – indicating and dry
pipes
• Gauges – air and water
• Piping
Pre-Action System
• Automatic sprinkler heads (closed) – upright and
sidewalls
• Automatic Detection Devices – electronic,
pneumatic, detection
• Control panel
• Operation
Common Problems
• Fire Department connection – not capped,
threads damaged, obstructions in piping,
visually obstructed
• Control valves and Trim – closed/obstructed,
not supervised or locked open, not listed, not
indicating, insufficient air pressure, dry pipe
flooded, and valve water column
Common Problems
• Gauges – broken or missing, not listed, improper pressure
• Piping – not secured, supporting items not associated with
sprinklers
• Automatic sprinkler heads – damaged, painted, improperly
installed, physically obstructed, improper temperature
rating
• Compressors – power off
• Enclosures – lack of heat
Common Problems
• Frozen piping
• Spare Supply of Sprinkler Heads – correct number,
correct temperature, wrench
• Test record – available upon request and up-to-date
• Fire Code requirements – check, inspect and test