Chapter 5 Flashcards
When a nozzle is above the level of the pump, there is:
pressure loss.
In order to convert head in feet to head pressure in psi, you must divide the number of feet by
2.304
If a gate valve resists turning after fewer than the indicated number of turns required to close the valve, the:
condition should be reported to the responsible agency.
Which of the following refers to stored potential energy available to force water through pipes, fittings, hose and adapters?
Static pressure
Which of the following refers to a circulating feed or looped line?
When a fire hydrant receives water from two or more directions
Which of the following is MOST likely a cause of friction loss in fire hose
Sharp bends
Which type of friction loss can usually be minimized by employing proper hose handling techniques?
Sharp bends in the hose
Rates of consumption allow engineers and fire protection personnel to determine:
adequacy of the water distribution system.
Which of the following BEST describes why altitude impacts the production of fire streams?
Because atmospheric pressure drops as height above sea level increases
Which statement about a gravity system is MOST accurate?
Uses a primary water source located at a higher elevation than the distribution system
When water converts to a gas, water vapor, or steam, the water:
only becomes visible as it rises away from the surface of the liquid and begins to condense.
In a grid system, large pipes (mains), with relatively widespread spacing, that convey large quantities of water to various points of the system for local distribution to smaller mains are called
primary feeders.
Which are the most common type of valves used on most public water distribution systems?
Nonindicating valves
The 6th principle of pressure states that the pressure of a liquid at the bottom of a vessel is:
independent of the shape of the vessel.
Which type of valve is commonly used on private water supply systems and the words open or shut appear in a window as the valve approaches one position or the other?
Post indicator (PIV) valve
A dead-end fire hydrant is a fire hydrant that:
receives water from only one direction.
For fire protection purposes, ordinary fresh water is considered to weigh:
8.3 lb/gal (1 kg/L).
Water may be used to smother fires in a combustible liquid:
when the liquid’s specific gravity is higher than 1.
Which is the BEST description of pressure?
Force per unit area
Which of the following refers to the portion of total available pressure not used to overcome friction loss or gravity while forcing water through pipes, fittings, hoses, adapters?
Residual pressure
Which means of moving water uses one or more pumps that take water from a primary source and discharge it through filtration and treatment processes?
Direct pumping system
Which of the following refers to the pressure found in a water distribution system during normal consumption demands?
Normal operating pressure
For water supply, most communities use a:
combination of the direct pumping and gravity systems.
The third principle of pressure states that pressure applied to a confined fluid is
transmitted equally in all directions.
The valves within a water distribution system should be:
inspected and operated yearly by the water supply utility
Which of the following is an action that fire departments should take when a large volume of water is needed in an area?
Request that water utility department increase water pressure
When engineers estimate the amount of water that a large city needs, the:
domestic/industrial requirements will far exceed that needed for fire protection.
The fifth principle of pressure states that the pressure of a liquid in an open vessel is:
Proportional to the dentisty of the liquid.
Which of the following refers to the forward velocity pressure while water is flowing from a discharge opening?
Flow pressure
Which of the following causes water hammer?
Suddenly stopping water moving through a hose or pipe
In a grid system, a network of intermediate-sized pipes that reinforce the grid and aid the concentration of required fire flow at any point are called:
secondary feeders.
A characteristic of water as an extinguishing agent is that it:
has a high surface tension that makes it somewhat difficult to soak into dense materials
Which of the following is a characteristic of water?
It has greater heat-absorbing capacity than other common extinguishing agents.
Most commonly, private water supply systems receive their water from a(an):
municipal water supply system.
The piping for fire protection and domestic/industrial services for private water supply systems are:
almost always separate.
The fourth principle of friction loss states that for a given velocity, friction loss is
approximately the same, regardless of pressure on the water.
The difference between static pressure and normal operating pressure is:
the friction caused by water flowing through the pipes, valves and fittings.
Which is an advantage to having separate piping arrangements for a private water supply system?
Neither of the systems is affected by service interruptions to the other
Which of the following is the MAIN concern of fire departments regarding water treatment facilities?
Maintenance failure or other events could disable pumping station(s) or severely hamper the purification process
The fourth principle of pressure states that the pressure of a liquid in an open vessel is
proportional to its depth.
If a property is served by both the municipal system and a private source consisting of nonpotable water:
measures must be taken to prevent cross contamination
Which of the following statements about atmospheric pressure is the MOST accurate?
Pressure is greatest at low altitudes and least at very high altitudes
Why does the third principle of friction loss demonstrate the advantage of larger size hose?
For the same discharge, friction loss varies inversely as the fifth power of diameter of hose.
Which of the following statements about fire hose and friction loss is MOST accurate?
The smaller the hose, the greater the velocity needed to deliver the same volume.
The first principle of friction loss states that if all other conditions are the same, friction loss:
varies directly with length of hose or pipe.
Which of the following refers to absolute zero pressure?
Perfect vacuum
The second principle of pressure states that fluid pressure at a point in fluid at rest is:
the same intensity in all directions
When a nozzle is below the level of the pump, there is:
pressure gain.
The second principle of friction loss illustrates that:
friction loss develops much faster than change in velocity.
Friction loss is that part of the total pressure lost:
while forcing water through pipe, fittings, fire hose, and adapters.
Which of the following statements about friction loss is MOST accurate?
Friction loss in a water system increases as length of hose or piping increases
Which of the following statements about water as an extinguishing agent is MOST accurate?
Generally, it is an inexpensive and readily available commodity.
Which of the following statements about water curtains is MOST accurate?
Radiant heat easily passes through water, rendering water curtains ineffective.
Which of the following refers to any pressure less than atmospheric pressure?
Vacuum
Which of the following statements about properties of water is MOST accurate?
Water is considered to be virtually incompressible.
The first principle of pressure states that fluid pressure is:
. perpendicular to any surface on which it acts.
Why is friction loss in newer, modern fire hose much less than in older fire hose?
Modern fire hose has a smoother inner lining.
Who should the fire department coordinate with before flushing hydrants in nonemergency situations?
Local water authority
