Chp 7 Flashcards
THE PRIMARY FUNCTION OF THE ENG IS TO PROVIDE WATER TO ATTACK CREWS IN SUFFICIENT VOLUME AND PRESSURE
NOTE
FL FACTORS
BIGGEST IS GPM
CONDITION OF HOSE AND COUPLINGS
KINKS
FRICTION LOSS
C: FRICTION LOSS COEFFICIENT
Q: FLOW RATE IN HUNDREDS OF GPM
L: HOSE LENGTH IN HUNDREDS OF FEET
DETERMINING FL COEFICCIENTS
SOME DEPTS MAY USE THEIR OWN ATTACK LINE TO DETERMINE
USE PITOT TUBE OR FLOW METER
TWO IN LINE GAUGES
HOSE WITH SMOOTH BORE NOZZLE (FOR PITOT) OR ANY NOZZLE FOR FLOW METER
APPLIANCE LOSS
IF <350 GPM, IGNORED
10 PSI AT 350 AND ABOVE
25 PSI FOR MS, REGARDLESS OF FLOW
ELEVATION PRESSURE LOSS
EP=0.5 X H
OR
EP=5PSI X NUMBER OF FLOORS -1
MULTIPLE HOSE LINES
IF EQUAL LENGTH AND DIAMETER, JUST CALC ONE
IF NOT, CALCULATE THE HIGHEST
WYED HOSE LINES
EQUAL LENGTH JUST CALCULATE ONE
SIAMESE HOSE LINES
FL FOR TWO LINES IS ~25% OF ONE
MASTER STREAMS
ADD 25 PSI
ELEVATED WATERWAY
ADD 25 PSI PLUS ELEVATION
COMMON NOZZLE PRESSURES
SOLID STREAM: 50 PSI
MASTER STREAM: 80 PSI
FOG NOZZLE: 100 PSI
LOW PRESSURE FOG: 50 OR 75
NET PUMP DISCHARGE PRESSURE
PDP LESS INTAKE PRESSURE
