Piping Flashcards
Pipes and fittings are made from which of the following materials
- glass
- plastic
- stainless steel
- all the above
Any substance or material that flows is defined as a
- fluid
Why is a steam trap used in a steam line?
- collect condensate
To make a turn, a pipeline is fitted with which of the following?
- elbow
What happens when sludge or corrosion reduce the I.D. of piping?
- pressure decreases
If the speed of a fluid is doubled, the friction will
- increase 4 times
Protective devices in a piping system include what components?
- filters
- strainers
- safety valves
- all of the above
Why are expansion joints installed in a pipline?
- allow for expansion and contraction of the line
What is the best insurance for keeping a piping system operating efficiently?
- routine preventive maintenance
Most piping system problems are caused by
- leakage and corrosion
What terms are used to express pipe diamensions
- outside diameter
- inside diameter
- inches and fractions of inches
- all of the above
A pipe smaller than 12” in diameter is normally designated by its
- I.D.
The wall thickness of a 12” in diameter, Schedule 80 (Extra-Strong) pipe is
- 1/2 (.500”)
What is the class of pipeline used to carry compressed air?
- service
A ferrous metal always contains
- iron
As fluid viscosity decreases, friction in the line
- decreases
Water hammer in a piping system occurs when the
- flow is suddenly slowed or stopped
Welded joints are preferred for applications that involve
- high temperatures, high pressures
One way to avoid weld icicles and splatter in a pipe weld is to use a
- backing ring
What is used to prevent oxides from forming when brazing a pipe?
- acid flux
Metal piping is sometimes lined with non-metallic piping materials to provide
- corrosion resistance
How much extra capacity, in percent, is a waste pipeline usually designed to have
- 40%
What is the strongest, most pressure-resistant concrete pipe?
- Reinforced-and-prestressed
Asbestos-cement pipe has the advantage of high resistance to
- corrosion
Plastic piping has which of the following qualities??
- Self-insulating properties
Sections of plastic pipe can be joined by which of the following methods
- threading
- welding
- butt-and-strap joints
- all the above
Which method can also be used to repair leaks in thermoplastic piping?
- fillet welding
The correct wrench to us on plastic pipe is
- strap wrench
What should you check for when maintaining nonmetallic piping?
- leakage
- corrosion
- secure supports
- all the above
Nonmetallic piping can be joined to metal piping by
- flanges
If the wall-thickness gage of tubing is not specified, you know that it is made to
- Birmingham Wire Gage (BWG)
Standard steel tubing ranges in size from
- 3/16” to 10-3/4”
- 1/32” to 12” Modern
Compared to pipe, tubing is
- flexible
Which of the following methods are used for joining tubing?
- brazing
- welding
- threading
- all the above
What kind of tubing would be used for a food-processing or “clean room” application?
- aluminum or stainless
With tubing, the term “impact method” refers to what kind of operation?
- flaring
Before tubing can be bent or flared, it should be
- annealed
Which of the following tube materials is strong enough to be threaded?
- steel
What type of tubing is best to use for low-pressure operation at extremely low temperatures?
- aluminum
Plastic tubes are joined by what method?
- fusion
What effects must hoses be protected against?
- temperature
- pressure
- corrosion
- all the above
What is the diameter of a -16 (dash 16) hose in inches?
- 1”
The most common hose for general use is of what type construction?
- Reinforced nonmetallic
The inner suction of a hose is called the
- tube
To what general classification of pressure does a hose carrying 2500PSI belong?
- medium (2500-3000)
The type of hose construction most suited to maximum suction is
- wire reinforced
The nonmetallic hose best suited for use at extremely low temperatures is
- dacron
Interlocked metal hose is used in what type of application?
- low pressure
Where materials are distributed from one source to several points, what kind of coupling will most likely be used?
- quick connect-disconnect
What should you look for when inspecting a steam hose?
- brittleness
- swelling
- softening or cover breaks
- all the above
Which of the following functions are performed with the use of fittings?
- change the direction of fluid flow
- provide branch connections
- change the size of pipe and tubing lines
- all the above
What does C/F (centreline to face) distance equal in a long radius elbow?
- 1-1/2 times the fitting diameter
For best fluid flow, which of the following elbows should be used?
- long radius
The fitting that provides two smaller branches is called a
- reducing cross
A union is used for which of the following?
- connect two sections of pipe or tubing
What can be used with screwed connections to make them leakproof
- paste dope
- teflon tape
- properly cut threads
- all the above
Which of the following flanged joints uses a gasket?
- bolted flange
A flange that has a plain or flat face should be joined to a flange that has a
- plain face
What fitting helps reduce the effect of water hammer?
- vibration dampener
Match the symbols in order of type of connections: flanged, welded, bell-and-spigot, soldered
- -II- , -X- , -)- , -O-
Most valves are named after the
- internal closing element
A gate valve that has two ports and is designed for fluid flow in one direction only is considered a
- two-way valve
Which of the following valves provides the most accurate throttling?
- needle
When an application calls for fast on-off operation, low pressure drop, good sealing, and flow in both directions, which of the following valves is the best choice?
- Ball valve
Large butterfly valves are most likely to be operated by
- electric or hydraulic power
The opening in the cylinder of a plug valve designed for throttling service is usually what shape
- diamond
Which of the following is true of a check valve?
- closes automatically
- ensures proper flow direction
- may be installed vertically or horizontally, depending on the type
- all of the above
What type of check valve should be used where pressure drop is the major consideration
- swing
Water for emergency showers is best controlled through use of
- quick-opening valves
The first step to good valve maintenance is
- careful, periodic inspection
What is the best valve to use for a vacuum application?
- diaphragm valve
Which of the following does a diaphragm valve eliminate?
- lubricant contamination of fluid
Blowoff valves in steam boiler applications are used to do which of the following?
- blow down boiler pressure
- rapidly lower boiler water level
- clear cleaning solution from boiler
- all of the above
What do pressure-regulating valves do?
- keep line pressure at a preset level
In valves, what is feedback?
- outlet pressure controlling inlet pressure
It is customary to install additional valves in a section of piping that includes which of the following valves?
- rupture-disc relief
- pressure regulating
- pressure reducing
- all of the above
The control unit of a temperature regulating valve includes a
- thermostat
The disc of a rupture-disc relief valve is usually made of
- metal
Which of the following would be installed to help balance pressure on either side of a main valve?
- bypass valve
A direct-opening valve is opened and closed by a
- solenoid plunger
Solid particles in the fluid have what harmful effects in a piping system?
- score pipe or tubing walls
- damage seals and fittings
- damage pump parts
- all the above
Which of the following valve problems is caused by solid particles in the fluid?
- valve closing elements jammed
Where is the coarse screen placed in a strainer?
- inside the fine screen
What should you do as the first step when removing a strainer for cleaning?
- shut off the line
On which side of the filter element do filtered particles collect?
- entry side
What is a filter through which all the oil in a system passes called?
- full flow
What happens in a piping system carrying saturated steam (100psi @ 170°) if the steam pressure drops to 50 PSI?
- steam flashes to superheated
Where there are slight variations in load or pressure, which of the following traps are usually used
- Upright or open bucket trap
In which of the following are air-vent valves used?
- oil lines
Why is it difficult to lubricate steam traps?
- because of water-steam mixture
It is necessary to maintain proper pressure level in a piping system to
- have the most efficient transportation of fluids
A pressure gage reads 30 PSI at sea level. What is tha absolute pressure?
- 44.7 psia
Fluid pressure of 10 psi is pushing against an area of 5 square inches, what is the total force against the area?
- 50 pounds
Which of the following gage elements are spring-loaded?
- plunger
- bellows
- bourdon tube
- all the above
The component that connects a revolving unit with a fluid line is called a
- rotary pressure joint
For what reasons can vacuum in a pipeline be a problem?
- fluids may run in wrong direction
- the line may collapse
- the fluid may become contaminated
- all the above
When pressure rises in a compressed air line, what happens to the air in the receiver?
- the air is compressed
Which of the following is the work performing element in an electric actuator?
- motor and screw-driven shaft
The area of an intensifier’s small piston is 2 square inches, area of the large piston is 6 square inches, input pressure is 40 psi. What is the output of the small piston in psi?
- 120 PSI
- piston area ratio
- output / input x pressure
Which of the following wrenches should you use on plated or polished pipe?
strap wrench
