4Th Class Power Engineering Chapter 49

Front 1

A ___________ gasket is typically used in a low pressure joint

Back 1

Full-face gasket

Front 2

___________ gaskets are generally used for high pressure and special services.

Back 2

Ring joint gasket

Front 3

__________ flanges are used in piping systems constructed from stainless steel or other costly materials.

Back 3

Van Stone flanges

Front 4

Three types of flanges

1.

2.

3.

Back 4

1. Screwed

2. Welded

3. Van Stone

Front 5

All fittings not properly or clearly identified should be _________.

Back 5

Rejected

Front 6

Name three types of steam traps.

Back 6

1. Mechanical

2. Thermostatic

3. Thermodynamic

Front 7

New lines must be blown clear of all foreign matter before installing the ______.

Back 7

Trap

Front 8

Copper and copper alloy piping and tubing is not used in power plants when __________ is a prime factor.

A. Pressure

B. Metallurgy

C. Temperature

D. Fluid commodities

Back 8

C. Temperature

Front 9

A good rule of thumb to use for pipe support is every

A. 10 m

B. 7.5 m

C. 5 m

D. 3 m

Back 9

D. 3 m

Front 10

The ASME Code for Pressure Piping contains sections on piping requirements for:

A.

B.

C.

D.

Back 10

A. Power piping

B. Industrial gas and air piping

C. Refinery and oil piping

D. Refrigeration piping systems

Front 11

Commercial pipe is made in standard sizes, each having several different wall thickness or weights. Above NPS-12, the size is given as the.

A. Actual outside diameter

B. Nominal inside diameter

Back 11

A. Actual outside diameter

Front 12

Schedule numbers 10, 20, 30 up to 160 are used to designate.

A. Nominal inside diameter

B. Wall thickness

C. Outside diameter

Back 12

B. Wall thickness

Front 13

Two general methods used to accommodate expansion in piping.

A.

B.

Back 13

A. Expansion bends

B. Expansion joints

Front 14

Two types of expansion joints

A.

B.

Back 14

A. Corragated

B. Slip

Front 15

Plastic foams used for pipe insulation are:

A) Glued directly to the pipe

B) For refrigeration system piping only

C) Used for high temperature service

D) Prohibited from power plant use

E) For lower temperature insulation purposes

Back 15

D) Prohibited from power plant use

Front 16

Welding together pipe size of 2 inch nominal size and smaller is usually done by:

A) The oxy-acetylene method

B) Non-pressure welders

C) The butt weld method

D) Pipe fitters

E) The socket weld method

Back 16

E) The socket weld method

Front 17

In most sizes of pipe, schedule forty corresponds to _____ wall thickness.

A) Higher

B) Reduced

C) Excessive

D) Regular

E) Standard

Back 17

E) Standard

Front 18

The Van Stone type flange fits on the pipe:

A) By welding to the inside of the flange

B) By evenly spaced set screws

C) By threads on the end

D) Loosely

E) In a fixed position

Back 18

D) Loosely

Front 19

A bellows type corrugated expansion joint is suitable for pressures up to approximately:

A) 500 kPa

B) 2 000 kPa

C) 15 000 kPa

D) 1 000 kPa

E) 30 000 kPa

Back 19

B) 2 000 kPa

Front 20

Double extra strong pipe is denoted by:

A) SS

B) DES

C) XXS

D) 2S

E) ES

Back 20

C) XXS

Front 21

By using backing rings in butt, welded pipes, the backing ring serves to:

A) Reinforce the pipe because of beveling at the joint

B) Align the pipe

C) Prevent welding gases from entering the pipe line

D) Reduce sludge flow

E) Support the pipe wall

Back 21

B) Align the pipe

Front 22

Cold water piping systems are usually insulated so that:

A) Appearance is improved

B) Water hammer is eliminated

C) The loss of heat is prevented

D) Corrosion is minimized or eliminated

E) The ingress of heat is prevented

Back 22

D) Corrosion is minimized or eliminated

Front 23

A _____ should be installed just ahead of a steam trap.

A) Non-return valve

B) Check valve

C) Pressure reducing valve

D) Sediment separator

E) Pressure gauge

Back 23

D) Sediment separator

Front 24

The main purpose of installing insulation on pipe systems is to:

A) Provide a paint surface

B) Prevent heat transfer

C) Prevent condensate from evaporating in the lines

D) Prevent injury to personnel due to contact with the bare surfaces of the pipe

E) Give the pipe a neat appearance

Back 24

B) Prevent heat transfer

Front 25

An insulation suitable for temperatures up to 430°C is:

A) Magnesia

B) Plastic

C) Cellular glass

D) Glass fiber

E) Asbestos

Back 25

C) Cellular glass

Front 26

Materials used for high pressure steam piping are:

1. Wrought iron

2. Cast iron

3. Carbon steel

4. Alloy steel

5. Forged steel

A) 1, 4, 5

B) 3, 4, 5

C) 4, 5

D) 1, 3, 4

E) 2, 3, 4

Back 26

B) 3, 4, 5

Front 27

A cold steam trap while in service indicates that the:

A) Steam is cold

B) Steam is not super heated

C) Trap is passing steam

D) Trap is plugged

E) Condensate line is frozen

Back 27

D) Trap is plugged

Front 28

The operation of a mechanical steam trap depends on the:

A) Difference in temperature between the steam and condensate

B) Liquid level in the condensate tank

C) Difference in pressure between the steam and condensate

D) Liquid level in the stream trap

E) Difference in specific gravity between the steam and condensate

Back 28

D) Liquid level in the stream trap

Front 29

Since cast iron has a high resistance to corrosion and abrasion, it is used for:

A) Blow off piping

B) Condensate lines

C) Ash handling systems

D) Underground steam lines

E) High pressure service

Back 29

C) Ash handling systems

Front 30

Up to and including 304.8 mm pipe, the size of the pipe is expressed as a measure of:

A) Outside radius

B) Thickness of wall

C) Circumference

D) Inside diameter

E) Outside diameter

Back 30

D) Inside diameter

Front 31

Materials used for water and instrument air piping in power plants are:

1. Cast iron

2. Copper

3. Brass

4. Galvanized steel

5. Alloy steel

A) 2, 3, 4, 5

B) 3, 4, 5

C) 1, 2, 3

D) 1, 2, 3, 4

E) 2, 3, 4

Back 31

E) 2, 3, 4

Front 32

A device which incorporates a swirling motion to remove moisture from a piping system is the:

A) Centrifugal separator

B) Steam trap

C) Baffle type separator

D) Chevron drier

E) Centrifuge

Back 32

A) Centrifugal separator

Front 33

Relative to pipe and fittings, an anchor chair is used to:

A) Hold a large fitting in a piping run

B) Support pipe

C) Install piping at considerable height

D) Anchor a slip type expansion joint

E) Allow for expansion and contraction of pipe

Back 33

B) Support pipe

Front 34

Forged steel is primarily used for:

A) Sewer lines

B) Pipe fittings

C) Water treatment piping and valves

D) Steam lines conveying super heated steam

E) Ash handling systems

Back 34

B) Pipe fittings

Front 35

Pipe is manufactured in two main categories; welded and:

A) Brazed

B) Seamless

C) Soldered

D) Threaded

E) Flanged

Back 35

B) Seamless

Front 36

_____ fittings are used to provide better flow of condensate.

A) Eccentric

B) Plastic

C) Concentric

D) Steel

E) Circular

Back 36

A) Eccentric

Front 37

A slip type expansion joint:

1. Is stronger than a bellows type

2. Is actually a pipe within a pipe

3. Can have packing added in service

4. Has a lubrication fitting

5. Is usually flame fitted to the pipe

A) 1, 2, 5

B) 2, 3, 5

C) 1, 2, 3, 4, 5

D) 1, 2, 3, 4

E) 1, 3, 4, 5

Back 37

C) 1, 2, 3, 4, 5

Front 38

As a piping and pipe fitting material, cast steel is used:

A) For construction of welded pipe

B) Mainly for instrumentation and control piping

C) Steam traps

D) Extensively for fittings

E) Primarily for special applications

Back 38

E) Primarily for special applications

Front 39

Piping insulation should have the following characteristics:

1. Be non-corrosive

2. Have a low heat conductivity

3. Have high eddy current values

4. Be easy to remove from the pipe 5. Retain its shape and insulating value when wet

6. Be vermin proof

A) 1, 3, 4, 5

B) 1, 3, 5, 6

C) 1, 2, 5, 6

D) 1, 2, 4, 6

E) 1, 2, 3, 5

Back 39

C) 1, 2, 5, 6

Front 40

Two fittings that can be found on a steam separator are:

1. Gauge glass

2. Pressure gauge

3. Vent valve

4. Steam trap

5. Safety valve

A) 1, 4

B) 4, 5

C) 1, 2

D) 2, 5

E) 2, 3

Back 40

A) 1, 4

Front 41

A gray cast iron fitting is identified by:

A) The letters G.C.

B) The letters G.C.I.

C) The letters G.C.I.F.

D) Not being marked on the fittings

E) The letters C.I.

Back 41

D) Not being marked on the fittings

Front 42

All classes of pipe of a given size have the same:

A) Expansion coefficient

B) Outside diameter

C) Inside diameter

D) Length

E) Mass per metre of length

Back 42

B) Outside diameter

Front 43

Before admitting any steam to a steam piping system, it is imperative to first:

A) Crack open the steam valve

B) Positively ensure that no water or condensate exist in the piping

C) Warm the line up properly

D) Ensure the steam pressure is at maximum value allowed without the boiler safety valve opening

E) Ensure drain valves are closed

Back 43

B) Positively ensure that no water or condensate exist in the piping

Front 44

As the wall thickness of a pipe increases, the:

A) Weight of the pipe decreases

B) Bore of the pipe increases

C) Pipe becomes less suitable for steam service

D) Outside diameter increases

E) Inside diameter is reduced

Back 44

E) Inside diameter is reduced

Front 45

If a heavier schedule pipe is used, the outside diameter is:

A) Smaller

B) Equal to the schedule number

C) Larger

D) Machined to match the other pipe size

E) Unchanged

Back 45

E) Unchanged

Front 46

Materials used for high pressure steam piping are:

1. Wrought iron

2. Cast iron

3. Carbon steel

4. Alloy steel

5. Forged steel

A) 2, 3, 4

B) 4, 5

C) 3, 4, 5

D) 1, 3, 4

E) 1, 4, 5

Back 46

C) 3, 4, 5

Front 47

A thermostatic trap is controlled by a:

A) Bucket that flips when filled with condensate

B) Temperature difference between condensate and steam

C) Combination of a bucket and a float

D) High level float control

E) Difference in velocity between condensate and steam

Back 47

B) Temperature difference between condensate and steam

Front 48

Materials most commonly used for sewer piping are:

1. Carbon steel

2. Cast steel

3. Cast iron

4. Plastic

5. PVC

A) 2, 3, 4

B) 3, 4, 5

C) 3, 4

D) 1, 2, 5

E) 1, 2, 3, 4, 5

Back 48

B) 3, 4, 5

Front 49

Before admitting steam to any system:

A) All valves must be closed

B) All valves must be open

C) Condensate must be removed from the system

D) All drains must be closed

E) Any check valves in the line must be opened

Back 49

C) Condensate must be removed from the system

Front 50

For varying wall thickness of pipe, tables are developed which give the dimensions and:

A) Weight in kg/m

B) Length in cm

C) Volume in m³

D) Thickness in cm

E) Diameter in cm

Back 50

A) Weight in kg/m