pump hydraulics

Theoretical and pump chart information

Formula for GPM

29.7(D²)√NP —> Where D is the diameter of the nozzle and NP is nozzle pressure

Formula for FL (Friction Loss)

C(Q²)L Where C is the set Coefficient, Q is quantity of water (GPM) divided by 100, L is hose length divided by 100

Formula for PDP (pump discharge pressure)

NP + FL + App ± Elev Add up nozzle pressure, friction loss in the hose, appliance consideration over 350gpm, elevation up or down 5psi per 10ft

Coefficient for 1.5” hose

24

Coefficient for 1.75” house

15.5

Coefficient for 2.5” hose

2

Coefficient for 3” hose

0.8

Coefficient for 5” hose

0.08

Theoretical Hydraulic Calc steps

1) Draw picture of the problem.

2) Label nozzle pressure and GPM for each nozzle

3) Determine and Label GPM for each line individually

4) calculate FL for each hose line seperately

5) Account for Elevation gain or loss

6) Account for appliances if over 350gpm

7) Calculate PDP by plugging in to formula.

Preconnect 1.75” w/ Elkhart nozzle (gpm and psi)

100gpm	150gpm	200gpm
100psi	135psi	200psi
(200ft)

Preconnect 1.75” w/ smoothbore 7/8” tip gpm and psi

150gpm	150gpm	150gpm
85psi	120psi	155psi
(100ft) bumper	(200ft)	(300ft) driver rear

2.5” w/ smoothbore gpm and psi

200gpm (1” tip)	265gpm (1 1/8” tip)	325gpm (1 1/4” tip)
(200ft)—> 65psi	80psi	95psi
(400 ft)—> 85psi	110psi	135psi

2 1/2” w/ Elkhart gpm and psi

	250gpm	325gpm
200ft	100psi	115psi
400ft	125psi	160psi

2 1/2” friction loss cheat rule

Smoothbore:

200gpm (no tips off) is 10psi FL

265gpm (1 tip off) is 15psi FL

325gpm (2 tips off) is 20psi FL

Elkhart:

250gpm flow is 15psi FL

325gpm is 20psi FL

Deck Gun details

105 psi PDP (80 at the discharge gauge)

1 3/8” tip: 500gpm (no tips off)

1 1/2” tip: 600gpm (1 tip off)

1 3/4” tip: 800gpm (2 tips off)

2” tip: 1000gpm (3 tips off)

Elkhart

100psi 1250gpm

Elkhart NP (new) 1 3/4”

65psi

Elkhart (old) 2 1/2” NP

75psi

Smoothbore handline NP

50psi

Smoothbore Master stream (deck gun and blitz monitor) NP

80psi

Any other fog nozzle NP

100psi

Wildland real world calcs

Start with 70 psi NP (for pump chart we use 100psi)

Add FR (3psi per 100ft for 25gpm) Maxi low

(10psi per 100ft for 70gpm)

(20psi per 100ft for 90gpm) Maxi high

(24psi per 100ft for 100gpm)

Add ± Elevation

Elkhart 1 ¾” gpm range

60-200gpm

Elkhart 2 ½” gpm range

75-325 gpm

Maxi fog 1 ½" gpm range

25 or 90gpm

Kocheck FSS 1” gpm range

10-25gpm

Bubble cup 1 ½” gpm range

20-60gpm

Bubble cup 1” gpm range

10-24gpm

Smoothbore tip GPM

1 ½ ” with 3/8“ tip

30gpm

1.5” hose with 1/2” tip gpm

50gpm

1.5” hose w/ 5/8” tip gpm

80gpm

1” hose with 3/16” tip gpm

7gpm

1” hose with 1/4” tip gpm

13 gpm

1” hose with 3/8” tip gpm

30gpm

Engine drafting steps

1) position apparatus for egress and drafting line on panel side if possible

2) chock tires

3) assemble strainer and draft lines with tight connections

4) Position draft line strainer in water with attached shovel or ladder to keep of ground

5) attach draft line to pump intake (add additional draft line if neccessary)

6) check all drains, valves and caps are CLOSED.

7) Finish Goldy 9. Engine in pump. Panel lights

8) Pump Boss in RPM mode or move PRV out of the way.

9) Two stage pumps in volume/capacity

10) Pump at 1200RPM

11) Primer for 45-60 sec max.

12) Signs of a draft: heavy draft line, drop in primer tone, DISCHARGE GAUGE has pressure!

13) Slowly give the water a place to go (Tank fill, recirc line, fire attack).

14) Switch back to PSI mode on the pump boss and Pressure more on a two stage pump (under 50psi)

Goldy 9 steps

1) Set brake

2) sound horn

3) place engine in pump

4) tank to pump (open - watch gauge)

5) tank fill (cracked open)

6) set chocks

7) panel lights/ground lights on

8) run up PRV

9) bump throttle to confirm pump is ready

After Goldy 9

1) Evaluate Hazards

2) check FF for PPE, tools

3)check hoses clear of bed

4)check hose lays for kinks

5) charge line slowly (watch gauge)

6) set PRV

7) visualize all hose line for problems

8) ensure correct tips on 2 ½” smoothbore

9) check tank level

10) turn on FOAM pro

11) prep tools for next operation (ric tools, other hoseline, ladders, etc)

12) scene lighting

13) make supply!

Steps when hydrant supply is lost

1) Open tank to pump

2) Close PIRV Intake

3) Shutdown nonessential lines (Deck gun, exterior lines)

4) Stabilize discharge pressure(s)

5) Notify “IC, engine 51 lost supply, shutdown exterior lines, full / ¾ / ½ tank.