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Calculating pump pressure: PP=NP+FL+/-ELFriction loss for appliances:Wyes and siameses 5 psiStandpipe/Sprinkler connections 25 psiPortable monitor: 15 psiElevation:Add or subtract 5 psi for every 10 feet of elevation 1 ½” hose friction loss:FL=Q2/3Q=gpm being flowed, drop last digit1 ¾” hose friction loss:FL=Q2/5Q=gpm flowing, drop last digit2 ½” hose friction loss:FL=Q-10 (Q=drop last digit of gpm)GPM for smooth bore tips: Hand Lines
Tip size 1” 1 1/8” 1 ¼”GPM 200 250 300
Master StreamsTip size
1 3/8”
1 ½”
1 5/8”
1 ¾”
1 7/8”
2”
GPM 500 600 700 800 900 1000
Rule of thumb numbers (pump pressures):1 ½” Trash lines (95 gpm) 125psi1 ¾” Crosslay (125 gpm) 100 psi nozzle 155psi1 ¾” Crosslay (125 gpm) 75 psi nozzle 130 psi
Maintain 150 psi for sprinkler systems
Friction loss constants (per 100 feet):1 ½” hose (95gpm) 25 psi1 ¾” hose (125 gpm) 30 psi2 ½” hose (200 gpm) 10 psi
If static pressure drops, possible to add # of lines of same size as line already in use:
20%-25% drop 1 line
15% drop 2 lines
10% drop 3 lines
5% drop 4 lines
Maintain 20 psi residual pressure for
safety!
Calculating pump pressure: PP=NP+FL+/-ELFriction loss for appliances:Wyes and siameses 5 psiStandpipe/Sprinkler connections 25 psiPortable monitor: 15 psiElevation:Add or subtract 5 psi for every 10 feet of elevation 1 ½” hose friction loss:FL=Q2/3Q=gpm being flowed, drop last digit1 ¾” hose friction loss:FL=Q2/5Q=gpm flowing, drop last digit2 ½” hose friction loss:FL=Q-10 (drop last digit of gpm)GPM for smooth bore tips: Hand Lines
Tip size 1” 1 1/8” 1 ¼”GPM 200 250 300
Master StreamsTip size
1 3/8”
1 ½”
1 5/8”
1 ¾”
1 7/8”
2”
GPM 500 600 700 800 900 1000
Rule of thumb numbers (pump pressures):1 ½” Trash lines (95 gpm) 125psi1 ¾” Crosslay (125 gpm) 100 psi nozzle 155psi1 ¾” Crosslay (125 gpm) 75 psi nozzle 130 psi
Maintain 150 psi for sprinkler systems
Friction loss constants (per 100 feet):1 ½” hose (95gpm) 25 psi1 ¾” hose (125 gpm) 30 psi2 ½” hose (200 gpm) 10 psi
If static pressure drops, possible to add # of lines of same size as line already in use:
20%-25% drop 1 line
15% drop 2 lines
10% drop 3 lines
5% drop 4 lines
Maintain 20 psi residual pressure for
safety!