4th Class Power Engineering Part B Ch97- Ch102 Questions & Answers.

CH.97

When installing a siphon it:

A )  must be perpendicular to the piping

B )  must be dry

C )  should be downstream of an inspectors' test connection

D )  should be first filled with water

E )  shall be as close to the boiler as possible

To increase the opening pressure of a safety valve:

A )  raise the blowdown ring

B )  increase spring compression

C )  reduce spring compression

D )  lower the blowdown ring

E )  increase the distance between the lip and the seat

A siphon tube is necessary to:

A )  prevent steam hitting the safety valve disc

B )  prevent water entering a steam gauge

C )  drain water from a bourdon tube

D )  prevent water from being siphoned out of the glass

E )  keep steam out of the bourdon tube

An LP safety valve lever test should be performed:

A )  weekly

B )  semi-annually

C )  monthly

D )  daily

E )  quarterly

A steam pressure gauge is graduated in:

A )  pascals

B )  pascals per square metre

C )  kilograms per square centimetre

D )  kilograms per hour

E )  kilopascals

When using a dead weight tester, the effect of friction:

A )  is reduced by rotating the platform

B )  will cause a higher than desired reading

C )  is negligible

D )  is eliminated with a lubricant

E )  is compensated for mathematically

In order to ensure a safety valve seats properly, it uses:

A )  seat rings

B )  a huddling chamber

C )  a blowdown ring

D )  guides and bushings

E )  a test lever

What does the boiler inspector install to prevent tampering with a safety valve setting?

A )  a restraining order

B )  a gag

C )  a seal

D )  a plug

E )  a cover plate

Blowdown of a safety valve is defined as:

A )  increase the pressure drop across the filter

B )  the difference between opening and closing pressures

C )  draining water from the safety valve

D )  opening the test lever to blow steam out

E )  the adjustment of the pressure setting of the valve

Testing the safety valve by means of the try lever method, is considered good practice when carried out on a:

A )  weekly basis

B )  monthly basis

C )  six monthly basis

D )  yearly basis

E )  bi-weekly basis 

CH.98

Gage glass rupture may be caused by:

A )  maximum allowable boiler pressure

B )  a cold draft

C )  a sudden pressure drop

D )  warming the boiler up too quickly

E )  improper boiler water treatment

Boiler outlet valves are usually:

A )  gate valves because of their low resistance to flow

B )  gate valves because of the ability to control flow

C )  globe valves because of their throttling capability

D )  globe valves because of their low flow resistance

E )  installed in tandem

A steam boiler is blown down in order to:

A )  clean the soot and carbon out of the firebox and tubes

B )  lower the operating water level in the boiler

C )  discharge sediment and scale forming matter from the boiler

D )  test the rated relieving capacity of the safety valves fitted to the boiler

E )  locate the steam level

A globe valve should be used in the feedwater line:

A )  at all times

B )  whenever it may be used for control purposes

C )  if it is of the OS&Y type

D )  when the system is of multiboiler installation

E )  because of its low flow resistance

The purpose of the small vent valve or cock located on top of the shell or on top of the water column on most boilers is:

A )  to allow water to escape from the boiler when the boiler is being filled with air

B )  to allow air in to the boiler when the boiler is being filled with water

C )  to allow water to escape before the steam stop valve is opened during the warm-up period

D )  to allow air to escape from the boiler when the boiler is being filled with water

E )  to allow water into the boiler when the boiler is being drained or cooled preventing the formation of a vacuum

When gage glass nuts are leaking:

A )  the gage glass should be replaced

B )  they should be tightened immediately

C )  new packing should be installed

D )  the glass should be isolated and depressurised before tightening

E )  they should be replaced

What is the size of the connecting pipes attached to a water column on a steam heating boiler?

A )  25 mm

B )  15 mm

C )  50 mm

D )  35 mm

E )  30 mm

LP steam boilers must be equipped with a marker indicating the:

A )  maximum water level line

B )  low water fuel cut-off line

C )  lowest permissible water line

D )  lowest visible water line

E )  fireline

Should the steam line or water line to a gage glass become plugged with sludge:

A )  gage glass level will drop in both cases

B )  gage glass level will drop in the first case and rise in the second

C )  gage glass level will remain where it was

D )  the gage glass will read high

E )  gage glass level will rise in the first case and drop in the second

Boiler water foaming may be the result of:

A )  low pH

B )  excessive blowdown

C )  low TDS

D )  high TDS

E )  dissolved gases

CH.99

When the pressure pointer of a closed system reads lower than the altitude pointer the:

A )  system is full of water

B )  expansion tank level will be high

C )  boiler is being over-fired

D )  gage is faulty

E )  system requires water

Hot water heating boilers must be equipped with a:

A )  thermometer

B )  fusible plug

C )  return trap

D )  blow down tank

E )  steam pressure gage

Open type expansion tanks:

A )  must be located below the heating system

B )  must be located outdoors

C )  are used with large hot water boilers only

D )  must be located above the heating system

E )  are used with small hot water boilers only

A hot water boiler is protected from over pressure by means of:

A )  a safety pop valve

B )  a high limit pressure control

C )  an expansion valve

D )  an air release valve

E )  a safety relief valve

An automatic fill valve:

A )  will maintain maximum system pressure at all times

B )  is a mandatory fitting

C )  is not mandatory

D )  opens only when expansion tank level is low

E )  can be used with an open tank system

Your boiler is operated with automatic water feeders. If the boiler suddenly requires an increase in water treatment, what should you look for?

A )  Make sure the blow-off valves are open.

B )  See if the chemical pump has stopped.

C )  Check for a loss of feedwater

D )  Check to see if the chemical supplier has sent the wrong chemicals.

E )  Nothing. Simply increase the pump stroke to put more chemicals into the system.

Which of the following fittings would you expect to find on a hot water boiler:1. thermometer 2. safety relief valve3. blow-off or drain valve4. water column

A )  1, 2, 4

B )  1, 2, 3

C )  2, 3, 4

D )  1, 2, 3, 4

E )  1, 4

An expansion tank is used to:

A )  store steam

B )  increase water temperature

C )  allow for the expansion of the water

D )  provide more efficient water circulation

E )  allow free expansion of the steam

How are stop valves, which are used on steam outlet connections of heating boilers, identified?

A )  they are stamped

B )  they have catalogue numbers

C )  with identification numbers

D )  with stickers

E )  with metal tags

In a hot water heating system, the closed type expansion tank should be:

A )  kept full of water

B )  open to the atmosphere

C )  partly filled with water

D )  isolated from the system

E )  closed and independently heated 

CH.100

How often would you test the low level fuel cut-off on a low pressure steam heating boiler by blowing out the float chamber?

A )  daily

B )  monthly

C )  semi-annually

D )  annually

E )  bi-weekly

In hot water boiler operation the maximum operating temperature should never exceed:

A )  77 °C

B )  87 °C

C )  100 °C

D )  121 °C

E )  131 °C

The most important rule in the safe operation of boilers is to:

A )  watch the steam pressure

B )  not overheat the boiler

C )  ensure an adequate supply of air

D )  ensure a fuel supply

E )  keep the correct water level

A gradual increase in stack temperature is an indication of:

A )  poor burner operation

B )  too much excess air

C )  unclean heating surfaces

D )  poor damper operation

E )  all of the above

Thermal shock to boilers can be reduced by:

A )  warming up boilers slowly

B )  keeping the boiler free of scale build-up

C )  covering the tube sheets with refractory

D )  not allowing full flow of cold water into a warm hot water boiler

E )  all of the above

In a low pressure steam boiler, the pressure must be no higher than:

A )  158.7 kPa

B )  207 kPa

C )  103 kPa

D )  109 kPa

E )  69 kPa

The maximum operating temperature of a hot water heating boiler is:

A )  100 ° C

B )  120 ° C

C )  200 ° C

D )  121 ° C

E )  160 ° C

It is very important that boilers should be:

A )  warmed up quickly to prevent condensation

B )  warmed up quickly to prevent scale build-up

C )  lit only when cool

D )  warmed up slowly to prevent thermal shock

E )  warmed up at a rate of one degree every five minutes

If the safety relief valve on your hot water boiler was opening up, the cause could be:1. steam collecting in the water space2. expansion tank completely filled with water3. faulty automatic fill valve4. circulating pump running too slow

A )  2, 3, 4

B )  1, 3

C )  2, 3

D )  2, 4

E )  1, 2, 3

Before starting up a new boiler or one that has been out of service the following must be ensured:

A )  the manufacturer's recommendations are read

B )  the boiler has a valid inspection certificate

C )  the fuel is shut off

D )  the boiler control is in the OFF position

E )  the boiler is cold 

CH.101

A radiator valve is used to control the amount of:

A )  air leaving the radiator

B )  condensate leaving the radiator

C )  steam leaving the radiator

D )  air entering the radiator

E )  steam entering the radiator

The purpose of a radiator trap is to:

A )  stop the flow of steam

B )  assist circulation within the radiator

C )  control the temperature of a radiator

D )  enable the radiator to be isolated

E )  pass condensate and retain steam in the radiator

Unit heaters differ from convectors in that they use _______ to increase heat transfer.

A )  metal fins

B )  natural circulation

C )  blowers

D )  copper tubes

E )  brass tubes

Convectors use ________ to increase heat transfer.

A )  metal fins

B )  radiators

C )  blowers

D )  copper tubes

E )  brass tubes

Radiators are usually made of:

A )  steel

B )  cast iron

C )  stainless steel

D )  copper

E )  brass

A frequent means of heating large facilities such as factories, warehouses and garages, is to use a:

A )  fin fan

B )  space heater

C )  convector

D )  radiator

E )  unit heater

In fin coil type heaters, individual room temperature is controlled by:

A )  switches

B )  automatic valves

C )  dampers

D )  air relays

E )  supply ducts

The difference between a convector and a radiator is:

A )  the way they transfer heat

B )  the way the heating medium goes through

C )  the method of control

D )  that one is made of cast iron and the other of steel or copper

E )  the way the heating and cooling is distributed

When air is forced through a heating coil, where the fan and coil are within the same unit, the unit is known as:

A )  a unit heater

B )  an injector

C )  a diverter

D )  an air vent

E )  a convertor

The vacuum pump performs the following function:

A )  supplies water to the condensate receiver

B )  supplies steam to the boiler

C )  returns the condensate (water) back to the boiler

D )  returns the condensate water to the condensate receiver

E )  none of the above

 CH.102

In a gravity return system the boiler should be placed:

A )  well above the highest radiator

B )  well below the lowest radiator

C )  on an elevated platform

D )  at the same level as the radiators

E )  in a central location

In the case of radiators and convectors, the main sources of trouble are the:

A )  air vents

B )  air traps

C )  push nipples

D )  connecting rods

E )  valves and traps

When starting up a steam heating boiler it should be filled to:

A )  the maximum level

B )  3/4 of a gage glass

C )  1/2 of a gage glass

D )  1/4 of a gage glass

E )  the very bottom of the gage glass

A pressure balancing device that prevents the boiler pressure from forcing the water in the boiler into the return line is called a:

A )  relief valve

B )  check valve

C )  pipe siphon

D )  pressure reducing valve

E )  Hartford loop

The piping and heating units of a steam heating system must be so arranged that:

A )  the condensate can flow freely to the heating units

B )  the air can be kept at the top of the heating units

C )  steam can flow freely to all heating units

D )  all of the above

E )  none of the above

Slow or insufficient heat in one or more rooms in a steam heated building can be caused by a:

A )  faulty steam trap

B )  faulty float switch

C )  faulty heater

D )  faulty vacuum switch

E )  faulty sight glass

Finned convectors should be kept free of:

A )  air

B )  steam

C )  corrosion

D )  dust

E )  all of the above

All supply and drain lines of a steam heating system must be pitched to:

A )  allow for drainage of condensate

B )  allow collection of air at the highest points

C )  prevent corrosion

D )  allow for temperature expansion

E )  all of the above

Slow or insufficient heat throughout a building heated by steam can be caused by:

A )  too high a firing rate

B )  too low a firing rate

C )  air leaks

D )  the feed water being too cold

E )  oversized piping

If the water level falls too low during operation of a steam heating boiler the operator should:

A )  tell his or her supervisor

B )  add more water immediately

C )  operate the safety valve

D )  shut the boiler down

E )  lower the flame and add water to bring it up to a safe level