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HH. H O U ST ON F I RE D E PA RT ME N T P U MP O P ER AT OR P R O GR AM VAL JAHNKE FIRE TRAINING FACILITY. Egineer/Operator Program. Pump Operations. Pump Equipment. Centrifugal Pump Pressure Relief Valve/Governor Intake Relief Valve Transfer Valve Positive Displacement Primers
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HH HOUSTONFIREDEPARTMENT PUMPOPERATORPROGRAM VAL JAHNKE FIRE TRAINING FACILITY
Egineer/Operator Program Pump Operations
Pump Equipment • Centrifugal Pump • Pressure Relief Valve/Governor • Intake Relief Valve • Transfer Valve • Positive Displacement Primers • Manual Pump Shift • Gauges • Auxiliary Cooler
Centrifugal Pump • Non-positive displacement pump • Three factors influence pump dischargepressure 1) Incoming pressure, 2) Speed of the impeller, and 3) The amount of water being discharged • Single or multi-stage • NOT self-priming • Cavitation
Pressure Relief Valve/Governor • Most common devices • Set while discharging at operating pressure • Set for highest operating pressure • Pressure relief valve - diverts water • Pressure governor - controls rpm
Intake Relief Valve • Also known as dump valve • Protects pump from water hammer and excessive intake pressure • Possibly capped during high pressure operations • Piston intake relief valve
Transfer Valve • Multi-stage pump only • Pressure (series) vs. Volume (parallel) • Most operations in pressure mode • 50% rule • Change over @ 50 psi net pump pressure
Positive Displacement Primers • Required for drafting • Most common - rotary vane • Operate for no more than 45 seconds • Priming oil • Environmentally safe primers
Manual Pump Shift • Provides back-up • Usually located on pump panel • Often require two persons to operate • Back-up throttle may have to be used • Exercise manual shift often
Gauges • Compound gauge • Master intake gauge (compound) • Master discharge gauge • Individual discharge gauge • Engine gauges
Auxiliary Cooler • Allows water from pump to cool engine • Use when temperature exceeds normal level • Close when temperature returns to normal • Keep in closed position
Valves • Main intake valve (suction)-keystone, piston, MIV • Auxiliary intake valve ( 2 ½ ) • Tank-to-pump valve • Tank fill valve • Discharge valves • Pump drain valve • Discharge drain valve • Intake drain valve
Booster Tank • Sizes • Tank-to-pump valve • Use only one handline • Obtaining positive source • Refill as soon as possible
Hydrant Operations • Two types of hydrants • Steamer should face street • Blue reflectors assist in locating • Color coded to main size • MUD Districts may not color code • Private hydrants - Apartments, Businesses
Water System Consumption • Peak use hours • Morning - residential areas • Mid day - downtown areas • Evening - residential areas • May contact Water Department to divert water to fire area
Drafting • Primary source for rural fire protection • Portable water supplies • Static water supplies
Theory of Pressure • Force: measure of weight • Pressure: measure of force per unit area
Pressure and Fluids • Pressure acts on fluids according to six basic principles • Fluid pressure is perpendicular to any surface on which it acts. • Fluid pressure at a point in a fluid at rest is of the same intensity in all directions. • Pressure applied to a confined fluid from without is transmitted equally in all directions. • The pressure of a liquid in an open vessel is proportional to its depth. • The pressure of a liquid in an open vessel is proportional to the density of the liquid. • The pressure of a liquid on the bottom of a vessel is independent of the shape of the vessel.
Hydraulic Calculations Engine Pressure = nozzle pressure + friction loss in the hose + friction loss in appliances + pressure due to elevation Nozzle Pressure - The amount of pressure required at the nozzle to produce an effective fire stream.
Nozzle Pressures • Fog nozzle 100 psi • Low pressure fog nozzle 75 psi • Vindicator nozzle (minimum) 50 psi • Solid stream handline 50 psi • Solid stream master 80 psi
Friction Loss The part of the total pressure lost while forcing water through pipe, fire hose, fittings, adapters, and appliances. The basis for fire hose friction loss calculations are the size of the hose, the amount of water flowing, the length of the hose lay, the age of the hose, and the condition of the lining. These factors give rise to the formula for computing friction loss: FL = C · Q · L
FL = C · Q · L • FL = friction loss in psi • C = coefficient ( constant ) • Q = flow rate in GPM/100 • L = hose length in feet/100
Friction Loss Coefficients • 1¾” - 15.5 • 2½” - 2.0 • 3” - .80 • 4” - .20
Example If 200 gpm is flowing from a nozzle, what is the friction loss in 200 ft. of 2½” hose? FL = C · Q · L C = 2 Q = gpm/100 = 200/100 = 2 L = length/100 = 200/100 = 2 FL = (2) (2) (2) = (2) (4) (2) = 16 psi
GPM Formula • It is possible to determine water flow from any solid stream nozzle when the nozzle pressure and tip diameters are known. The following formula is used to determine the GPM flow of solid stream nozzles: GPM = 29.7 ·d2 ·NP
GPM = 29.7 ·d2 ·NP GPM= Discharge in gallons per minute 29.7 = A constant d = Diameter of the tip (inches) NP = Nozzle pressure in psi (square root)
Example Determine the water flow from a 2” tip operating at 80 psi. GPM = (29.7) (d)2 (NP) = (29.7) (2)2 (80) (use 81) = (29.7) (4) (9) = (118.8) (9) = 1069.2 GPM (1070)
Appliances • Reducers • Gates • Wyes • Manifolds • Heavy Stream Piping
Appliance Friction Loss • Small appliances: • Less than 350 GPM - no friction loss • More than 350 GPM - 10 psi friction loss • Master streams: • 25 psi friction loss
Standpipes • No friction loss for piping • Allow for elevation only • 5 psi per floor for elevation • Can be negative number • pumping to basement
Total Engine Pressure • EP = NP + FL + Appliance + Elevation
Example • What is the engine pressure for 200 ft. of 1¾” hose flowing 200 gpm, with a low pressure fog nozzle, on the third floor? EP = NP + FL + Appliance + Elevation EP = 75 + 125 + 0 + 15 EP = 215 psi
Wyed Hoselines • Complex pumping situation • Common with apartment lay • Same size and type • Different size • Communication with crews
Pressure vs. Volume • Common misconception • Maximum capacity at draft • Maximum capacity with positive pressure • Net pump pressure
Calculating Additional Water Available • Static pressure • Residual pressure • Percentage drop: static -residual • Formula • Percentage Drop = (Static - Residual) (100) • Static
Water Available Table Percent Decrease Water Available 0 - 10% 3 x amount 11 - 15% 2 x amount 16 - 25% same amount Over 25% less than being delivered
Multiple Discharges • Different Pressures • Different Friction Loss Calculations • Gating Back Discharges • Set Pressure Relief Device/Governor
Master Streams • Most Common - Deck Gun, Ladder Pipe • Nozzle Tips Flowing 400-1500 GPM • Solid Bore - 80 psi Nozzle Pressure • Fog Nozzle - 100 psi Nozzle Pressure • 25 psi Friction Loss
Standpipes and Sprinklers • Usually have a 2 ½” connection • Hook up with 3” high pressure hose or 4” hose with adapter • Reverse lay • DO NOT PUMP UNLESS ORDERED
Non-PRV Systems • Standpipe: • Fog Nozzle: 150 psi + 5 psi per floor • Solid Stream 65 psi + 5 psi per floor • Sprinkler: • 150 psi + 5 psi per floor • Elevation loss is calculated to the fire floor
PRV Systems • Pump the designed pressure if known • If the designed system pressure is unknown: • 100 psi + 6 psi per floor to the top floor of the zone • When pumping into a PRV system, the standpipe outlet pressure cannot be raised above its designed pressure
Relay Pumping • Necessary when the required GPM flow of the attack pumper cannot be met because of friction loss in the supply line • Pump pressure is based on GPM needed and distance between pumpers • 20-50 psi residual in addition to friction loss • Relay initiated by pumper at water source
Relay Pumping • Intermediate pumpers - close pump to tank valve, open 2½” discharge until water discharges, close discharge, place in pump gear and open supply to next pumper • Discharge pressures should not exceed 200 psi, if pressure required to supply water is greater than 200 psi, another pumper or additional lines are needed
Relay Pumping • Relay is designed to deliver volume not pressure • Relay is terminated by attack pumper by decreasing pressure, followed by next pumper in relay, etc.
Foam OperationsPortable Eductors • Do not start foam operations unless incident can be terminated with resources available • Portable eductors require 200 psi @ eductor • Emulsifiers can be educted @ 1/2 or 1% • Nozzle setting must be @ 95 gpm • Apparatus will carry 6 - 5 gallon containers of foam and 2 - 5 gallon containers of cold clean