Hose Operations and Hose Streams Flashcards
What is the difference between a Hose stream and a fire stream?
They are interchangeable.
They both refer to the stream of water that comes out of the hose to extinguish the fire.
What factors can limit the availability of water from fire hydrants?
- Damage to hydrants
- Broken water mains
- Greater demand than anticipated
- Frozen pipes
- Closed isolation valves
- Dead-end water mains
Which of the following is not allowed to inspect a fire hydrant?
Firefighters, inspectors, police officers, water department personnel, private contractors.
Police
What are the two types of fire hydrants used in North America?
Dry-barrel and wet-barrel
What are the two essential componants that all fire hydrants have?
One 4 or 4.5 inch pumper outlet
Two 2.5 inch couplings
How large does the valve of a water main need to be to meet NFPA 1963?
6 inches
How large does the diameter of the valve of a standard three way hydrant need to be to meet NFPA 1963 standards?
5 inches
Where are dry-barrel hydrants designed to be used?
Cold climates
What is the main difference between dry barrel hydrants and wet barrel hydrants?
Dry barrel hydrants contain water underground where it will not freeze in winter, where as wet barrel hydrants are found in warmer climates and contain the water with in the hydrant itself.
What factors could lead to a fire hydrant being labelled as out of service?
- Damage to hydrant or piping or pump
- Repairs or upgrades being performed on the hydrants or pipes or pump
- Frozen componants
- Blockage due to an object
If you find a fire hydrant that is showing signs of malfunction, what steps should you take to mark it as out of service?
- Label it as out of service
- Notify fire department and water department
What are the most commonly used tools during hydrant operations?
Spanner wrench, Hydrant wrench, Rubber mallet, Gate valve, hydrant valves
What is the difference between a spanner wrench and a hydrant wrench?
Spanner wrenches are used for attaching hose to the fire hydrand valves, and the hydrant wrenches are used for opening the stem nut and opening the discharge caps.
What are the four most common uses of gate valves?
- Allow additional hoselines to be laid to the hydrant
- Connect a supply pumper to the hydrant
- Boost pressure in the original supply line without interrupting flow
- You can precharge a line for another pumper to use before it arrives
What is a hose clamp and what are they used for?
They prevent the discharge of water by creating a break in the hoseline to change a burst section of hose, add more hose all without interupting the flow path.
What are the four kinds of hose clamps used in firefighting?
Screw down, Press down, Hydraulic press, wildland
What skills must firefighters be able to perform with fire hydrants?
- Provide water for fire operations
- Flow water to discharge sediment in the hydrant
- Perform inspections
- Ensure proper operations
- Assist in flow test
True or false, water hose is designed to accomidate the pressures of fire hydrants, so it is ok to open them fast.
False, opening the fire hydrants quickly and discharging lots of pressure at once is called a water hammer. It can cause the hose to flail, create punctures in the hose, and more. Also, closing the hydrant too quickly can damage the hydrant.
When twisting the Stem nut of a dry barrel fire hydrant, does the valve move upward or downward, and how does this affect the drain valve?
The valve moves downward to allow water into the hydrant, this movement causes the drain holes to be closed. When the valve is lifted back up, the drain holes are opened and the water is able to drain.
Why is it so important for dry barrel hydrants to be opened and closed fully?
Because a partial opening causes an opening in the drain hole, which will decrease the water pressure and erode the soil arround the hydrant.
How do you test the drain hole of a dry barrel hydrant?
Leave one of the hose valves open as you close the stem nut, then place your palm on the opening of the open valve, if there is negetive pressure, the hydrant is emptying and if not then retry. If it continues to not drain, notify the water department.
What are intake strainers?
They are attached to the drafting ends of hard intake hoses and they filter out debris that could damage the pump.
What are hose rollers?
They are rollers used to ease the laying, collection and drainage of hose. They can protect against sharp edges and prevent mechanical friction damage.
What are hose bridges?
They protect the hose from tire damage by creating a ramp
What are chafing blocks?
Objects that are used to protect the hose from vibrating against sharp objects or rough pavement.
What is a hose strap?
A length of rope that is tied around the hose and around the shoulder of a firefighter to assist in pulling the hose forward.
True or false, wyes have one female inlet and multiple male outlets
True
What is the difference between a siamese and a wye?
A siamese connects multiple lines into one line, a wye turns one line into multiple lines.
Siamese have two female inlets and one male outlet, whereas wyes have one female intake and multiple male outlets.
What are manifolds and trimese?
The name is interchageable but they are siamese with three inlets.
What are hydrant adapters?
They allow different thread styles to connect to a fire hydrant
What are reducers?
They are used to transfer the water from a large diameter hose to a smaller diameter hose to increase pressure.
What is a forward lay?
Laying hose from the nearest hydrant towards the incident. A female coupling should be the first removed from the apparatus so it can be attached to the hydrant.
What is the primary advantage of a forward lay?
The apparatus is close to the incident and therefore the equipment is close at hand and the pump operator can see the incident.
What is a four-way hydrant valve operation?
Crew 1 one arrives at the scene and establishes a forward hose lay to the fire. They anticipated help arriving, so they placed a four-way gated valve on the hydrant with only one gate open to supply the fire.
Crew 2 arrives and needs to add pressure to the original fire hose line, but they don’t want to cut off the pressure to the fire, so they connect to the four-way gate valve. They attach a hose length from the left most gate towards the apparatus.
then they attach another hose legth from the apparatus to the centre gate of the hydrant. They pressurize the line with water from the apparatus, then they switch the setting on the hydrant valve so that water from the hydrant goes through the left most length, gets pumped by the apparatus through the center gate and ejected out of the right gate towards the fire.
What are some of the disadvantages of a reverse hose lay?
- Firefighters must remove all necessary equipment from the apparatus before it departs to the water source.
- The apparatus operator is occupied with the apparatus and cannot help in other duties.
When advancing hose into a strucure, what should the spacing be between all the firefighters helping with the hose?
15 to 20 feet
Before entering a building, what tool should you use to determine the heat inside?
A thermal imager, but if you don’t have one you can spray the top of the door and see if it steams.
Which load and carry method is excellent on vertical hose advances?
The minuteman
What is a standpipe?
A pressurized water system that is built into structures for easier access to water in tall buidlings
True or false, firefighters must always connect to the standpipe one floor below the fire floor.
False, if the standpipe is in an enclosed stairway they can use it on the firefloor.
How tall does a structure need to be before it requires a stanpipe?
Typically 3 stories or more.
Why is it important to secure the hose of an improvised standpipe?
Because the water weight has a tendency to drag the hose downward otherwise.
What are the eight factors that can affect the hose stream?
- Velocity of the water agent
- Flow rate of the water
- Gravity
- Wind direction and speed
- Air friction
- Operating pressure
- Type of nozzle
- Condition of the nozzle
What are the uses of hose streams?
- Reducing temperature of burning material and gases for firefighter advancement
- Disperse hot smoke and gas
- Water curtain to protect firefighters and property
- Creating a barrier between fuel and fire
- Hydraulic ventilation
What kind of stream does a smooth bore nozzle create?
Tightly packed solid stream
What type of stream does an fog nozzle create?
A fog or a straight stream
When water is converted into steam, it expands to fill a space how many times greater than its original space?
1,700 times larger
True or false, a solid stream of water absorbs more heat than a fog nozzle because it produces greater pressure and speed of discharge, which allow for greater heat absorbtion.
False, fog nozzles absorb more heat more quickly because it creates a greater surface area, as the water particles are more spread out.
True or false, a smooth bore nozzle operates at higher pressures than fog nozzles.
False
What are some advantages of using smooth bore nozzles over fog nozzles?
They are less prone to clogging
Can opperate at low pressures
Can be used to apply compressed air foam
What are some disadvantages of smooth bore nozzles?
- Do not allow for stream selection
- May allow hose lines to kink
What are some of the advantages of a fog nozzle?
- Adjustable discharge patterns
- Can protect firefighters
- Offers a variety of nozzle choices
- Can be used to apply certain types of foam
What are the four types of fog nozzles?
- Basic fog nozzle
- Constant gallonage fog nozzle
- Contant pressure fog nozzle
- Contant/selective gallonage fog nozzle
What is the discharge rate for a handline and for a master stream?
Up to 1000 L/m for handlines
Up to 10000 L/m for master lines
What are the three most commonly used broken stream devices?
- Piercing nozzle, hammered through a wall to produce a stream on the other side
- Bresnan distributor, has many holes that shoot water perpendicular to the hose line and it spins.
- Rockwood Cellar pipe. Similar to the Bresnan.
What are the three kinds of nozzle control valves?
- Ball
- Slide
- Rotary
How does a ball valve work?
A Ball is suspended within the nozzle, when it fully blocks the passage fo the water, the water stops and when it is fully open, the water flows at maximum velocity.
How does a slide valve work?
A cylinder is pressed against a cone to form a seal and prevent the passage of water, when it is open it allows water to pass.
Slide valves are particularily good at preventing turbulance during a partial opening.
What is the discharge rate of a low-volume stream?
Less than 160 L/min
What is the discharge pressure of a handline stream?
Between 160 and 1400 L/min
What is the discharge rate of the master stream?
Greater than 1400 L/min
What is a critical flow rate?
The amount of water that is necessary to absorb the heat created by a fire. Too much water application creates unnecessary water damage and too little will not extinguish the fire.
What are the four types of hose streams?
- Solid
- Straight
- Broken
- Fog
What is the difference between a straight stream and a solid stream?
A straight stream is one that is produced by an adjustable nozzle, which creates a semisolid stream.
A solid stream is produced by a smooth bore nozzle and maintains a solid stream of water for far longer than an adjustable nozzle.
What four factors limit the affect of hose streams?
- Gravity
- Velocity loss
- Friction with air
- Wind
True or false, a single firefighter is allowed to handle the hose by themsleves if the incident is in a small building or is a small fire taking place outside.
True
