math

Question 1

Friction loss for RAM

Answer 1

75 psi if flowing 500 gpm

50 psi if flowing 400 gpm

Question 2

Preferred hose size for RAM

Answer 2

3”

Question 3

Find Available Water

Answer 3

1. static reading
2. note drop after first line
   3 multiply drop by square of the velocity t o se if original flow may be doubled, triple, ect.
3. subtract total drop from original static pressure
4. product of #3 and your original flow rate will determine flow

Question 4

Minimum Hydrant Residual Pressure on Compound gauge?

Answer 4

20 psi

Question 5

PSI for a standpipe system

Answer 5

25 psi for FDC and riser

Question 6

PSI for a sprinkler system

Answer 6

150 psi

Question 7

Calculate relay operations

Answer 7

flow relay plus 20 psi for residual pressure

Question 8

Maximum pressure flucuation

Answer 8

10 psi

Question 9

Siamese Hoselines, master stream ground monitor

Answer 9

25 psi

Question 10

calculate wyed hoselines

Answer 10

10 psi for the wye if flowing 350 gpm or greater

Question 11

Master steams appliances

Answer 11

add 25 psi for master steam devices

Fog- 100 psi
solid stream- 80 psi

Question 12

Elevation psi

Answer 12

add 5 psi for each flow excluding first or 5 psi per 10’ of elevation

Question 13

GPM Parameters- Solid Stream

Master streams

Answer 13

Master steams (80 psi nozzle pressure)
1 1/4"   400 gpm
1 3/8"   500 gpm
1 1/2"   600 gpm
1 5/8"   700 gpm
1 3/4"   800 gpm
1 7/8"   900 gpm
2"   1000 gpm

Question 14

GPM Parameters- solid stream

Hand lines

Answer 14

Hand lines (50 psi nozzle pressure)
1” 200 gpm
1 1/8” 250 gpm
1 1/4” 300 gpm

Question 15

Unequal Size lines 2 1/2” and 3”

Answer 15

total Gpm-  FL- 100 ft.
500-  10 psi
600-  15 psi
700-   20 psi
800-   25 psi
900-   30 psi
1000-  35psi

Question 16

3” skidload

Answer 16

Fog nozzle-
90 psi + 6 psi per 100’ of 3”

Smooth nozzle-
70 psi + 9 psi per 100” of 3”

Question 17

2 1/2” skidload

Answer 17

Fog nozzle-
135 psi + 7 psi per 100’ of 2 1/2”

Smooth nozzle-
125 psi + 10 psi per 100’ of 2 1/2”

Question 18

2 1/2” preconnect pressure and gpm

Answer 18

200” of preconnect
Fog- 250 gpm at 105 psi
Smooth- 300 gpm at 90 psi

Question 19

1 3/4” Preconnect pressure and gpm

Answer 19

200’ of preconnect
Fog- 175 gpm at 155 psi
Smooth- 200 gpm at 150 psi

Question 20

3” hose pressure

Answer 20

Q squared
175 gpm- 3 psi
200 gpm- 4 psi
250 gpm- 6 psi
300 gpm- 9 psi
350 gpm- 12 psi
400 gpm- 16 psi
500 gpm- 25 psi
600 gpm- 36 psi

Question 21

2 1/2” hose pressures

Answer 21

Subtract 10 method from Q
175 gpm- 7 psi
200 gpm- 10 psi
250 gpm- 15 psi
300 gpm- 20 psi
350 gpm- 25 psi
400 gpm- 30 psi
500 gpm- 40 psi

Question 22

1 3/4” hose pressure loses

Answer 22

175 gpm- 40 psi

200 gpm- 50 psi

Question 23

Friction loss fomula

Answer 23

FL= CQ2L

2 is squared

Question 24

R.A.M for 100’ of both 3” and 2 1/2”

Answer 24

500 GPM- 25 psi for 3” (each 100’) and 75 psi for the RAM= 100 psi

400 GPM- 30 psi for the 2 1/2” (each 100’) and 50 psi for the RAM= 80 psi