SAFE 874
Case Study 6
Sprinkler Systems
For the math problems, you must show your work. If you use an NFPA standard to obtain the answer,
cite the standard.
1. What is the minimum distance a standard spray pendent sprinkler head can be placed from a
wall?
2. What is the maximum distance a standard spray pendent sprinkler head can be placed from a
wall in an ordinary hazard occupancy?
3. What is the maximum distance between branch lines that has spray pendent sprinkler head
allowed in an extra hazard occupancy (Assume the system is hydraulically calculated and the
design density is .30)
4. What is the definition of an Ordinary Hazard Group 1 occupancy?
5. What is the maximum protection area for a sprinkler head in a light hazard occupancy? The
construction is noncombustible and the sprinkler system is hydraulically calculated.
6. A system will be designed with a design area of operation of 1,500 square feet. If the occupancy
was classified as an Ordinary Hazard Group 2 location, what is the design density in gpm/ft2?
7. A sprinkler system was desined for an Extra Hazard Group 1 location. The design area of
operation was 3,000 square feet and a density of .30 gpm/ft2. What is the minimum water flow
at the most remote sprinkler head?
8. What is the required water pressure a sprinkler head knowing the head has a k-factor of 5.6 and
the water flow is 25 gpm?
9. What is the coefficient of friction (C) value for unlined cast iron piping?
10. What would the expected friction loss be in 10 feet of Schedule 10 unlined cast iron pipe that
has an inside diameter of 2.157 inches and 25 gpm of water flowing through it?
11. What is the inside pipe diameter of Schedule 30 3” pipe?
12. A 2” diameter pipe has a 90 degree elbow. When calculating the friction loss of water going
through the elbow, how many feet of piping is the elbow equivalent to?
13. What is the maximum number of heads I can have on either side of a cross main in an ordinary
hazard occupancy?
14. What is the temperature rating and color coding for a glass bulb sprinkler head with an ordinary
temperature classification?
15. What is the minimum number of spare sprinkler heads should I have on hand?
16. I have 300 feet of water main pipe running from the riser that has an available water pressure of
30 psi. The pipe has a coefficient of friction (C) value of 100. What is the maximum pipe
diameter I can use if the design requires the system to provide 120 gpm of water flow at the
remote end of the water main with a minimum water pressure of 28 psi?(5 points)