Module 5.1 Knowledge Questions

Question 1

The protective conductor installed on a primary gas meter within 600mm of the meter outlet is known as…

a) a temporary continuity bond
b) a supplementary bond
c) a main equipotential bond
d) an earth bond

Answer 1

c) a main equipotential bond

Question 2

It is acceptable to use compression fittings on gas ….

a) in suspended timber floors
b) under the screed to a concrete floor
c) where they cannot be seen
d) in accessible locations

Answer 2

d) in accessible locations

Question 3

The only system of jointing allowed in a protected shaft is…

a) Screwed or welded steel pipe
b) Silver soldered copper joints on copper
c) Soft soldered capillary joints on copper
d) Compression joints on copper

Answer 3

a) Screwed or welded steel pipe

Question 4

When using soft soldered capillary joints on copper the flux.

a) is not needed
b) should be applied to the pipe ends and the inside of the fittings
c) should be applied to the pipe ends only
d) should be applied to the inside of the fittings only

Answer 4

c) should be applied to the pipe ends only

Question 5

Gas pipes running vertically behind a dry lining should….

a) only be of corrugated stainless steel
b) be totally encased by adhesive dabs
c) be removed as this is not allowed
d) be jointed with compression fittings

Answer 5

b) be totally encased by adhesive dabs

Question 6

The regulator on a primary gas meter is….

a) set at 20 mbar
b) set to give a pressure of 21mbar +/- 2mbar
c) of the lead weight type
d) positioned upstream of the emergency control valve

Answer 6

b) set to give a pressure of 21mbar +/- 2mbar

Question 7

The correct specification for a temporary continuity bond is…

a) not less than 1.2m long, csa 10mm2 of 250v rated single core flexible insulated cable
b) not more than 1.2m long, csa 5mm2 of 450v rated multi core flexible insulated cable
c) not less than 1.2m long, csa 10mm2 of 450v rated multi core flexible uninsulated cable
d) the same as battery booster cables

Answer 7

a) not less than 1.2m long, csa 10mm2 of 250v rated single core flexible insulated cable

Question 8

Flexible hoses for use on gas cookers are manufactured to…

a) BS 1212
b) BS 1057
c) BS 669
d) BS 864-2

Answer 8

c) BS 669

Question 9

A medium pressure fed installation is one in which the regulator inlet pressure ….

a) exceeds 21mbar but does not exceed 1 bar
b) exceeds 75mbar but does not exceed 3 bar
c) is lower than that of a low pressure installation
d) exceeds 75mbar but does not exceed 2 bar

Answer 9

d) exceeds 75mbar but does not exceed 2 bar

Question 10

‘No perceptible loss’ on a water pressure gauge is…

a) when there is absolutely no movement of the meniscus during the tightness test
b) less than 0.25mbar
c) is less than 0.2 mbar
d) 0.5 mbar

Answer 10

b) less than 0.25mbar

Question 11

The correct sequence for attaching a temporary continuity bond is…

a) Both uninsulated clips to be attached to the pipe at the same time
b) 1st insulated clip to upstream side followed by 2nd insulated clip to downstream side
c) 1st insulated clip to downstream side followed by 2nd insulated clip to upstream side
d) 1st uninsulated clip to downstream side followed by 2nd uninsulated clip to upstream side

Answer 11

b) 1st insulated clip to upstream side followed by 2nd insulated clip to downstream side

Question 12

The limits for notching of joists to Approved Document A is…

a) min 0.07 x span to max 0.25 x span
b) min 0.25 x span to max 0.07 x span
c) min 0.125 x span to max 0.25 x span
d) min 0.25 x span to max 0.125 x span

Answer 12

a) min 0.07 x span to max 0.25 x span

Question 13

The correct maximum spacing for clips on a 15mm gas pipe is…

a) 1.8m vertical and 1.2m horizontal
b) 1.8m horizontal and 2.4m vertical
c) 1.5m vertical and 1.8 horizontal
d) 2m vertical and 1.5m horizontal

Answer 13

d) 2m vertical and 1.5m horizontal

Question 14

Sleeves for gas pipes….

a) can contain a pipe joint
b) must always be sealed both internally and externally at both ends
c) should span the full width of the wall be continuous and sealed internally at one end
d) should be tight fitting and made of steel

Answer 14

c) should span the full width of the wall be continuous and sealed internally at one end

Question 15

The cross sectional area of a gas pipe duct is 0.08m3 what size of air vent will be required?

a) No air vent required
b) The air vent is always the same as the csa of the duct
c) 0.05m3
d) 1/50th of the cross-sectional area of the duct

Answer 15

c) 0.05m3

Question 16

Excessive flux applied to pipe fittings prior to soldering may cause a partial blockage within the pipework. Which of the following is not a consequence of this fault?

a Increased pressure to appliances.
b Increased pressure loss through the fitting.
c Corrosion of the pipe from inside in the future.
d Unsound joints being temporarily sealed with excess flux.

Answer 16

a Increased pressure to appliances.

Question 17

A compression joint is acceptable for use on gas pipework. Which of the following situations should compression fittings be avoided?

a Within garages.
b In bedroom.
c Beneath floor boards.
d Within a roof space.

Answer 17

c Beneath floor boards.

Question 18

When using a blowlamp to solder a capillary fitting in situ on an existing installation that has previously contained gas, which of the following actions must be carried out?

a Ventilate the property thoroughly.
b Use only compression fittings.
c Remove and cap the meter.
d Install permanent equipotential bonding.

Answer 18

c Remove and cap the meter.

Question 19

Prior to the connection of any pipework to an existing gas installation, the gas operative must:

Answer……

Answer 19

Carry out a tightness test

Question 20

A temporary continuity bond should be used when:

a Testing an installation for tightness.
b Purging installation pipework.
c Fitting a tee into an existing pipe section.
d Removing a gas appliance from the supply.

Answer 20

c Fitting a tee into an existing pipe section.

Question 21

When protection against corrosion is used, the protection applied must:

a Extend at least 25mm beyond the corrosive surface.
b Extend at least 50mm beyond the corrosive surface.
c Extend at least 75mm beyond the corrosive surface.
d Extend at least 100mm beyond the corrosive surface.

Answer 21

a Extend at least 25mm beyond the corrosive surface.

Question 22

Wrapping a gas pipe as it passes through a wall is acceptable as an alternative to pipe sleeving if a 50% overlap is used:

a. True.
b. False.

Answer 22

b. False.

Question 23

When pipework is buried beneath the ground used for pedestrian traffic, it should buried at least:
a 20mm below the surface.
b 30mm below the surface
c 40mm below the surface.
d 50mm below the surface.

Answer 23

c 40mm below the surface.

Question 24

When pipework is to pass through the cavity of a structure, it must be:

a Constructed of medium gauge steel.
b Must take the shortest route, be sleeved and the sleeve sealed at the inner end only.
c Be routed only in ventilated cavities.
d Pipes must never pass through cavities.

Answer 24

b Must take the shortest route, be sleeved and the sleeve sealed at the inner end only.

Question 25

The maximum distance between 22mm light gauge copper pipe supports for internal horizontal runs is:
a 1 .0 metre.
b 1 .5 metres.
c 2.0 metres.
d 2.5 metres.

Answer 25

c 2.0 metres.

Question 26

No person shall install any gas installation pipework in any shaft, duct or void which is not adequately ventilated to?

a Ensure that minor gas escapes (within the permitted leakage rate) do not build up and create an unsafe situation.
b Prevent the pipework from overheating.
c Prevent the pipework from corroding.
d Allow for expansion and contraction of the pipework

Answer 26

a Ensure that minor gas escapes (within the permitted leakage rate) do not build up and create an unsafe situation.