A9 Flashcards
What is the pressfit piping system primarily designed for?
a) Large-bore piping systems
b) Small-bore piping systems (NPS ½ to NPS 2)
c) High-pressure gas transmission
d) Underground sewage systems
Small-bore piping systems (NPS ½ to NPS 2)
What is the pressure rating for Pressfit joints used in general service systems?
a) 150 psi
b) 200 psi
c) 300 psi
d) 400 psi
300
What type of groove is created by machining a groove in the pipe end?
a) Cut groove
b) Rolled groove
c) Threaded groove
d) Welded groove
Cut groove
What is a major advantage of the grooved piping method?
a) Requires specialized welding tools
b) Easy assembly and disassembly
c) Does not support high-pressure systems
d) Limited to metallic pipes only
Easy assembly and disassembly
What type of pipe preparation is required for Pressfit joints?
a) Welding
b) Threading
c) Square cut, plain-end
d) Flanging
Square cut, plain-end
What is the recommended expansion compensation method for rigid Pressfit systems?
a) Thermal welding
b) Flexible mechanical coupling
c) Threaded connections
d) Reduced pipe thickness
Flexible mechanical coupling
Which type of grooved joint is recommended for pipes with walls thinner than standard weight?
a) Cut groove
b) Rolled groove
c) Threaded groove
d) Welded groove
Rolled groove
What is the main sealing component of a grooved pipe joint?
a) Metal coupling
b) Elastomeric gasket
c) Welded flange
d) Threaded fitting
Elastomeric gasket
What is the main advantage of flexible couplings in a piping system?
A) They create a rigid connection
B) They allow for controlled pipe movement
C) They are less expensive than other types
D) They require no maintenance
They allow for controlled pipe movement
Flexible couplings reduce stress caused by which factors?
A) Electrical surges
B) Thermal changes and seismic activity
C) External impacts
D) Corrosion
Thermal changes and seismic activity
What feature of flexible couplings helps minimize noise and vibration transmission?
A) Rigid clamping
B) Elastomeric gasket
C) Metal housing
D) Expansion loops
Elastomeric gasket
In what situation would rigid couplings be preferred over flexible couplings?
A) In areas with high seismic activity
B) For long piping runs with no branches
C) In mechanical rooms to control piping motion
D) In underground pipelines
In mechanical rooms to control piping motion
What should a piping system designer consider when selecting a grooved joint gasket?
A) The size of the pipe only
B) Temperature and service conditions
C) Color of the gasket
D) Cost of the gasket
Temperature and service conditions
Why is proper gasket selection important in grooved piping systems?
A) It increases the aesthetic appeal
B) It ensures maximum life and performance
C) It eliminates the need for flexible couplings
D) It reduces the overall cost of the system
It ensures maximum life and performance
What is the primary purpose of using synthetic rubber gaskets in grooved piping products?
A) To provide a tight seal
B) To add flexibility to the pipe
C) To reduce the weight of the piping system
D) To enhance the appearance
To provide a tight seal
What is the consequence of exceeding temperature limits of gasket materials?
A) Increased system efficiency
B) Degrading effect on the polymer
C) Enhanced durability
D) Reduced noise levels
Degrading effect on the polymer
What is the significance of pressure-temperature ratings in grooved mechanical pipe joints?
A) They determine the color of the pipe
B) They are used to select the right piping material
C) They ensure the piping system can withstand specific pressures and temperatures
D) They are not relevant to the design process
They ensure the piping system can withstand specific pressures and temperatures
What does the term “free-floating system” refer to in piping design?
A) A system that uses only rigid couplings
B) A system allowed to thermally expand or contract without expansion joints
C) A system completely fixed in place
D) A system with no supports
A system allowed to thermally expand or contract without expansion joints
How can a piping system designer prevent harmful bending moments at branch connections?
A) By ignoring pressure thrusts
B) By anchoring the system and directing movements
C) By using only flexible couplings
D) By reducing the pipe diameter
By anchoring the system and directing movements
What is one characteristic of flexible grooved-type couplings that must be considered during design?
A) They are completely rigid
B) They have linear and angular movement capabilities
C) They do not require any maintenance
D) They increase system rigidity
They have linear and angular movement capabilities
What should be considered when positioning hangers in systems using flexible couplings?
A) The weight of the pipes
B) The color of the pipes
C) The angular and rotational movement at joints
D) The diameter of the pipes
The angular and rotational movement at joints
What must be done if joints in a piping system are to remain deflected?
A) Use lighter hangers
B) Allow joints to move freely
C) Anchor the lines to restrain pressure thrusts
D) Ignore lateral forces
Anchor the lines to restrain pressure thrusts
In a grooved piping system, what is necessary when anticipating simultaneous linear and angular movements?
A) Increase the pipe diameter
B) Install additional joints to accommodate both movements
C) Use rigid couplings only
D) Decrease the number of hangers
Install additional joints to accommodate both movements
What is the role of lateral restraint in anchored systems with deflected joints?
A) To reduce the number of supports
B) To prevent sideways movement due to pressure thrusts
C) To increase the flexibility of the system
D) To eliminate the need for anchors
To prevent sideways movement due to pressure thrusts
When designing for thermal movement in grooved piping systems, what is the first step?
A) Estimate the pipe material cost
B) Compute the exact change in the linear length of the piping system
C) Select the color of the pipe
D) Install all rigid couplings
Compute the exact change in the linear length of the piping system
What is a benefit of using flexible couplings in expansion loops?
A) They increase pipe rigidity
B) They absorb thermal growth and contraction
C) They eliminate the need for hangers
D) They are cheaper than rigid couplings
They absorb thermal growth and contraction
Why should rigid couplings not be used in expansion loops?
A) They are difficult to install
B) They cannot accommodate angular deflection
C) They are more expensive
D) They require more maintenance
They cannot accommodate angular deflection
Where should the expansion loop ideally be located in relation to an anchor?
A) At the farthest point from the anchor
B) Adjacent to the anchor within four pipe diameters
C) Exactly in the middle of the pipeline
D) It doesn’t matter where it’s located
Adjacent to the anchor within four pipe diameters
What must be done to accommodate thermal expansion if the anticipated movement exceeds the capacity of the flexible joints?
A) Increase the pipe diameter
B) Install additional expansion joints
C) Reduce the operating temperature
D) Decrease the number of flexible couplings
Install additional expansion joints
Why is it essential to consider the actual expansion coefficients for different pipe materials?
A) They help in selecting the right color for the pipes
B) Different materials have varying expansion rates
C) All materials have the same expansion rate
D) Expansion coefficients are irrelevant
Different materials have varying expansion rates
In the calculation of thermal movement, what factors need to be considered?
A) Pipe color and diameter
B) Pipe length and temperature changes
C) Manufacturer’s brand and cost
D) Installation date and pipe thickness
Pipe length and temperature changes
What is the purpose of aligning guides in an expansion loop?
A) To reduce the number of required couplings
B) To ensure proper pipe alignment
C) To eliminate the need for hangers
D) To prevent thermal expansion
To ensure proper pipe alignment
What is the purpose of main anchors in piping systems?
A. To allow free movement of pipes
B. To prevent movement due to pressure thrust and thermal growth
C. To guide the direction of pipelines
D. To act as decorative elements
To prevent movement due to pressure thrust and thermal growth
Where are main anchors typically installed?
A. Randomly along the pipeline
B. At or near terminal points and changes in pipe direction
C. Only at pipe bends
D. In the middle of long pipelines
At or near terminal points and changes in pipe direction
What is the main role of intermediate anchors?
A. To prevent thermal expansion
B. To divide a long pipe run into individual expanding sections
C. To provide decorative support
D. To eliminate the need for main anchors
To divide a long pipe run into individual expanding sections
What happens to pressure thrust on intermediate anchors?
A. It doubles
B. It cancels each other out
C. It gets redirected to main anchors
D. It causes structural damage
It cancels each other out
What is necessary to prevent piping from being forced inside by pressure thrust?
A. Flexible couplings
B. A pressure thrust anchor
C. Lateral bracing
D. Rigid pipes
A pressure thrust anchor
Why might intermediate anchors be required in piping systems?
A. To manage pipe color coordination
B. To support and guide the pipe against movement
C. To reduce pipe diameter
D. To replace main anchors
To support and guide the pipe against movement
What should be used where thermal movement of pipes is significant?
A. Flexible couplings
B. Rigid joints
C. Plastic piping
D. Decorative anchors
Flexible couplings
Where should a main thrust anchor be located in a riser with branch connections?
A. At the midpoint
B. At or near the base of the riser
C. At the top of the riser
D. At every branch connection
At or near the base of the riser
What spacing is recommended for intermediate anchors between upper and lower anchors?
A. Every branch length
B. Every other branch length
C. Every two meters
D. Every coupling length
Every other branch length
What does thermal movement in pipes require?
A. Reduction of pipe diameter
B. Allowance for expansion
C. Elimination of anchors
D. Installation of rigid pipes only
Allowance for expansion
Why is guidance necessary for risers without branch connections?
A. To increase pressure
B. To prevent buckling of the riser
C. To reduce installation time
D. To lower pipe costs
To prevent buckling of the riser
Why is flexibility important in piping systems?
A. To accommodate structural misalignment
B. To minimize thermal expansion
C. To prevent system vibration
D. All of these
All of these
How can grooved piping systems benefit earthquake-prone areas?
A. By being inexpensive to install
B. By reducing vibration transmission
C. By eliminating pipe supports
D. By increasing system rigidity
By reducing vibration transmission
What is the role of sway bracing in seismic design?
A. To remove vibration entirely
B. To limit pipe movement during seismic events
C. To reduce system installation time
D. To increase pipe pressure
To limit pipe movement during seismic events
What is a critical practice in seismic design for piping systems?
A. Adding extra weight
B. Aligning pipes with the building structure
C. Removing all flexible joints
D. Minimizing pipe length
Aligning pipes with the building structure
