Determining Flow With Pre-Piped Monitors; Stream Trajectory Data - Task Force Tips MASTERSTREAM Series Instructions For Installation, Safe Operation And Maintenance

3.4 DETERMINING FLOW WITH PRE-PIPED MONITORS

The simplest procedure to determine fl ow with automatic nozzles is with a fl ow meter. If a fl ow meter is unavailable, then the
fl ow may be estimated using pressure loss data between the nozzle and an in-line pressure gauge at the pump or considerably
upstream from the nozzle. Data is taken with a smooth bore nozzle and handheld pitot gauge. Note: Equations assume no
substantial change in elevation between in-line pressure gauge and nozzle.
Step1: Determine fl ow of smooth bore nozzle.
Flow water with a smooth bore nozzle and record the nozzle's size, pitot pressure and in-line pressure gauge reading. The smooth
bore nozzle's fl ow is calculated from the Freeman formula:
Where: F = 29.71 for English units (GPM, INCHES, PSI)
F = .667 for metric units (LPM, MM, BAR) Note: 1 BAR=100 KPA
Q fl ow in GPM (or LPM)
smooth
D exit diameter in INCHES (or MM)
P pitot pressure in PSI (or BAR)
pitot
Step 2: Find pressure loss constant.
Using the results from step 1, use the following equation to calculate the pressure loss constant between the in-line pressure gauge
and the nozzle:
Where: C piping pressure loss constant in GPM2/PSI (or LPM2/BAR)
P in-line pressure gauge reading in PSI (or BAR)
inline
Step 3: Calculate fl ow with automatic nozzle.
Using the pressure loss constant from step 2 and the following equation, the fl ow with an automatic nozzle can be calculated for
your particular installation.
Where: Q automatic nozzle fl ow in GPM (or LPM)
auto
P nominal nozzle operating pressure in PSI (or BAR)
auto
Mount a graph or table of the results adjacent to the in-line pressure gauge. Deliver any desired fl ow by adjustment of pump
pressure.

3.5 STREAM TRAJECTORY DATA

Figures 4A - 4E give the stream trajectory for the Masterstream Series nozzles at various fl ows.
Notes on trajectory graphs:
• Graphs show approximate effective stream trajectory at 30 degrees elevation in no wind conditions. Distance to last water
drops approximately 10% farther.
• To estimate trajectories at elevations other than 30 degrees, refer to document LTT-135, available at www.tft.com.
• Trajectories shown are for water. The addition of foam is expected to decrease the reach by 10%.
• Tail or head winds of 20 MPH (30 KPH) may increase or decrease the range approximately 30%.
• Stream trajectory of Masterstream 4000 based on "The Trajectories of Large Fire Fighting Jets" by A.P. Hatton
Osborne, Reference: "The International Journal of Heat and Fluid Flow", Vol 1 No 1.
0 10
80
70
MASTERSTREAM 1000/1250s, 100 PSI (7 BAR, 700 KPA )
60
50
40
30
20
10
0
0 20 40
GPM
CURVE FLOW
A 300
B 400
C 500
D 800
E 1000
©Copyright Task Force Tips, Inc. 1999 - 2011
METERS
20 30 40
A
60 80 100 120 140
HORIZONTAL DISTANCE (FEET)
LBS
REACTION
150
200
260
400
510
FIG 4A - Masterstream 1000 Stream Trajectory
Q = F x D
smooth
C =
P
Q =
auto
50 60 70
D
B
C
160 180 200 220
CURVE
A
B
C
D
E
12
2
P
pitot
2
Q
smooth
- P
in-line pitot
(P - P
in-line auto
and
80 90
20
10
E
0
240 260 280 300
LPM KGF
FLOW REACTION
1100 70
1500 90
1900 120
3000 180
3800 230
LIM-030 April 29, 2011 Rev13
)C
M.J.