Pumps & Piping Systems

Question 1

A(n) ____________ is an assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements.

Answer 1

stuffing box

Question 2

___________ is a spontaneous vaporization of the fluid inside a pump, resulting in a degradation of pump performance, as well as noise, vibration, impeller pitting, and structural damage to the pump casing.

Answer 2

Cavitation

Question 3

Why is this concentric reducer arrangement to be avoided?

Answer 3

There is a risk of large air bubbles growing in the high point and eventually being swept into the pump impeller.

Question 4

About what thickness of grout would be typical under a pump skid?

Answer 4

1-1/2”

Question 5

A(n) _______________________ for a pump and piping system refers to the study of how the system behaves when there are sudden changes in flow, pressure, or operating conditions. These changes can result from events such as starting or stopping pumps, valve closures or openings, changes in load, or other time-varying disturbances that affect the system. The goal is to understand the dynamic response of the system, including pressure surges, flow variations, and the potential for damage or inefficiencies caused by these transients.

Answer 5

transient analysis

Question 6

Name four (4) scenarios where a VFD for a new pump would be a good idea.

Answer 6

1. Variable flow requirements: When the system needs different flow rates depending on the situation, like in a building with varying water usage throughout the day.
2. Maintaining constant pressure: If a constant pressure needs to be maintained even when the flow rate changes, a VFD can adjust the pump speed to compensate.
3. Energy efficiency: By allowing the pump to operate at a slower speed during low demand periods, a VFD can significantly reduce energy consumption.
4. Pump protection: VFDs can help protect pumps from damage by preventing sudden starts and stops, and by allowing for soft starts and smooth acceleration.

Question 7

One of the most common transient phenomena in pump and piping systems is ______________. It occurs when a sudden change in flow velocity (such as closing a valve quickly or turning off a pump) causes a pressure wave to travel through the system. This pressure wave can lead to dangerous pressure spikes, vibration, and even rupture of pipes if not properly controlled.

Answer 7

Water hammer

Question 8

What type of pump are these?

Answer 8

Vertical multi-stage pumps

Question 9

What type of pump are these?

Answer 9

Vertical single-stage centrifugal pumps

Question 10

Name some advantages of a vertical centrifugal pump over a horizontal centrifugal pump.

Answer 10

1. Better suitability for high suction lift applications.
2. Flexibility in installation in deep wells or sumps.
3. Reduced vibration and noise.
4. Ability to handle high flow rates with a smaller footprint, especially in multi-stage designs.

Question 11

Name some advantages of a horizontal centrifugal pump over a vertical centrifugal pump.

Answer 11

1. Simpler design and maintenance, which makes them easier to operate and repair.
2. Lower initial cost and better cost-effectiveness for many standard industrial applications.
3. Higher efficiency in typical low-to-moderate pressure and flow applications.
4. Versatility, with a wide range of applications in industries such as water treatment, chemical processing, and cooling systems.

Question 12

What is represented by this line in this flow diagram?

Answer 12

Minimum continuous stable flow

Question 13

Name at least one software application that can perform a transient analysis?

Answer 13

AFT Impulse, Synergi Pipeline Simulator, WinTran, KYPipe Surge, and PIPENET Transient Module. All of these are designed to simulate pressure surges and water hammer events within piping networks by analyzing rapid changes in flow conditions over time.

Question 14

What is the wall-mounted device in this picture?

Answer 14

VFD (Variable Frequency Drive)

Question 15

A(n) _______________ is an electrical device that controls the speed of an electric motor by varying its input voltage. VFDs are used to control pumps, fans, conveyor belts and other types of machinery in industrial plants.

Answer 15

VFD (Variable Frequency Drive)

Question 16

A(n) __________________ is simply a method of containing fluid within a vessel (typically pumps, mixers, etc.) where a rotating shaft passes through a stationary housing or occasionally, where the housing rotates around the shaft. This does not include packing.

Answer 16

mechanical seal

Question 17

What is the alternative to a mechanical seal, if a mechanical seal is not used?

Answer 17

Mechanical packing, also known as packing or gland packing

Question 18

What is this piece of equipment called?

Answer 18

Hydropneumatic tank (aka pressure tank)

Question 19

If a pump has a stuffing box, can it also have a mechanical seal?

Answer 19

Yes, a pump with a stuffing box can also have a mechanical seal; in fact, a mechanical seal is often installed within the stuffing box of a pump, effectively replacing the traditional packing material that would otherwise be used in the stuffing box to create a seal around the rotating shaft.

Question 20

What is a stuffing box for a pump?

Answer 20

A stuffing box is a chamber around the pump shaft where sealing material (like packing) is placed to prevent fluid leakage. Alternatively, a mechanical seal may be installed within the stuffing, effectively replacing the traditional packing material.

Question 21

What does IPS stand for?

Answer 21

Iron Pipe Size. It is the original pipe sizing system from the early 19th century. IPS is typically used for black iron or carbon steel pipe, and is available in sizes from ¾-in. to 65-in.

Question 22

What does DIPS stand for?

Answer 22

Ductile Iron Pipe Size. This pipe sizing system was created in 1948. DIPS is typically used for cast or ductile iron pipe, and is available in sizes from 4-in. to 36-in. DIPS piping has a larger outside diameter (OD) than IPS piping. For example, a 30-in DIPS pipe has a 32-in OD, while a 30-in IPS pipe has a 30-in OD.

Question 23

What are the main differences between IPS and DIPS?

Answer 23

DIPS pipes typically have a larger outside diameter compared to IPS pipes of the same nominal size. In IPS, the nominal size usually refers to the outside diameter, while in DIPS, the outside diameter is more precisely controlled.

Question 24

What is attached to the pipe in this picture?

Answer 24

Tracer wire

Question 25

What is the purpose of tracer wire?

Answer 25

Tracer wire is used to locate buried utilities, such as pipes, cables, and irrigation systems. It’s buried alongside the utility during installation and helps workers find it later.

To find the utility, a technician uses a transmitter to send a signal through the tracer wire. A receiver then pinpoints the location of the wire, which indicates the location of the utility.

Question 26

Green tracer wire typically indicates what kind of utility?

Answer 26

Sanitary sewer systems

Question 27

Red tracer wire typically indicates what kind of utility?

Answer 27

Electrical power

Question 28

Yellow tracer wire typically indicates what kind of utility?

Answer 28

Gas, oil, dangerous materials, product lines

Question 29

Blue tracer wire typically indicates what kind of utility?

Answer 29

Water systems

Question 30

Orange tracer wire typically indicates what kind of utility?

Answer 30

Communication, cable television, fiber optics

Question 31

What does “DR” stand for when referring to HDPE piping?

Answer 31

Dimension Ratio. It is the ratio of the pipe’s outside diameter to its minimum wall thickness.

Question 32

What does “SDR” stand for when referring to HDPE piping?

Answer 32

Standard Dimension Ratio. It is a specific set of DR values based on a standardized series of numbers, used to ensure consistency in pipe manufacturing across different applications.

Question 33

What does HDPE stand for?

Answer 33

High Density Polyethylene

Question 34

Does a higher Dimension Ratio (DR) for HDPE mean a thicker, or thinner wall thickness?

Answer 34

Thinner