Module 5 Pipework and Fittings

Question 1

New gas pipework within dwellings cannot be made of lead, lead alloy or any non-metallic substance unless it is a flexible hose connected to a flueless, moveable gas appliance.

True or False?

Answer 1

True

Question 2

When doing hot work in a small house can you leave the meter in place?

Answer 2

No, hot work within 10m of a meter means it must be removed and stored in a well ventilated area.

Question 3

If you bury copper pipe work in a floor does it need protection from corrosion?

Answer 3

Yes, must have one of the following:

a) Factory bonded PVC coat
b) Sit in non corrodible duct/sleeve
c) Wrapped with corrosion resistant tape

Question 4

When designing a new pipe installation what is the maximum pressure drop that is allowed?

Answer 4

1mbar

Question 5

Name three points about pipework installed in ducts

Answer 5

1) Screwed or welded steel
2) Vent – top and bottom
3) Must not impair fire resistance of the structure

Question 6

What distance is required between gas pipe and electrical installations?

Answer 6

a) Electrical meters / fuse boxes = 150mm
b) Electrical cables = 25mm

Question 7

If the cross sectional area of a duct is 0.005m² the ventailation free area required is:

a) none
b) Cross Sectional Area of duct
c) 0.05m²
d) 1/150 of cross sectional area of duct

Answer 7

a) none

If duct less than 0.01m² no additional vent required

Question 8

If the cross sectional area of a duct is 10m² the ventailation free area required is:
a) none

b) Cross Sectional Area of duct
c) 0.05m²

d) 1/150 of cross sectional area of duct

Answer 8

d) 1/150 of cross sectional area of duct for each opening

Duct exceeds 7.5m²

Question 9

If the cross sectional area of a duct is ² the ventailation free area required is:

a) none
b) Cross Sectional Area of duct
c) 0.05m²
d) 1/150 of cross sectional area of duct

Answer 9

b) Cross Sectional Area of duct - each opening

For duct sizes between 0.01 and 0.05m²

Question 10

What are the limits for drilling holes in a joist?

Answer 10

a) max diameter ¼ joist depth
b) between ¼ and 2/5 of length from edge
c) holes drilled halfway down
d) holes not closer than 3 x diameter from each other

Question 11

What diameter cable should be used for cross bonding?

Answer 11

At least 10mm²

Question 12

What is the maximum depth and how far from the edge can a notch be?

Answer 12

a) max 1/8 joist depth
b) max ¼ of length from edge

Question 13

What is the interval for supporting copper pipe on a vertical run? 15mm, 22mm and 28mm

Answer 13

15mm = 2.0m
22 & 28mm = 2.5m

Question 14

Why should surplus flux be wiped off?

Answer 14

To avoid corrosion in the future

Question 15

What is the interval for supporting copper pipe on a horizontal run? 15mm, 22mm and 28mm

Answer 15

15mm = 1.5m
22 & 28mm = 2m

Question 16

Where can’t compression fittings be used?

Answer 16

Where they are not readily accessible e.g. buried in a structure, below ground

Question 17

In practise if a pipe passes through a cavity what do you do?

Answer 17

1) Take the shortest route
2) Use gas tight sleeve, sealed to wall at both ends
3) Seal gas pipe at the internal side only

Question 18

If you lay a pipe in a solid floor what is the minimum screed depth?

Question 19

Gas pipe work should be located 150mm away from a fuse box and 25mm from an electrical cable. If this is not practical what two options can be used?

Answer 19

1) Cover pipe with electrical insulating material
2) Separate pipe and fuse box with insulating material

Question 20

Where should an emergency control valve be located?

Answer 20

As close a practical to the point of entry into the dwelling

Question 21

Pipe work – which is preferred bends or elbow joints?

Answer 21

Bends

Question 22

How close to the meter can you use TRAC pipe?

Answer 22

600mm – the first bit must be rigid pipework

Question 23

Can you use PE pipe inside a property?

Answer 23

No

Question 24

What is the minimum depth deep that a pipe must buried on the two places marked?

Answer 24

a) 375mm min open ground
b) 40mm min below concrete

Question 25

Name four key points about an ECV

Answer 25

1) Must be accessible
2) Clearly labelled + how to use
3) Permanent handle / lever
4) Fall into the off position

Question 26

Can hemp be used on threaded joints?

Answer 26

Only in conjunction with a thread sealing compound

Question 27

For an internal meter how close should the bonding be?

Answer 27

600mm on the downstream side

Question 28

The British standard specifications for pipes and fittings can be found in which module of the BPEC domestic gas safety manual?

Answer 28

Module 5

Question 29

When pipe sizing a good rule of thumb is that for every 10kW how many m³/h of gas is required?

Answer 29

Just under 1 m³/h (0.94m³/h)

Question 30

Where should a pressure test point be located in relation to an ECV?

a) Upstream
b) Downstream
c) Either up or down

Answer 30

b) Downstream

Question 31

When altering existing pipe work what two key things do you need to do?

Answer 31

1) Tightness test IGE/UP/1B
2) Cross bonding

Question 32

There is one exception that allows you to run gas pipe in the cavity. What is it?

Answer 32

For a fanned flued living flame effect fire which is designed to sit in the cavity wall

Question 33

If the cross sectional area of a duct is 5m² the ventailation free area required is:
a) none

b) Cross Sectional Area of duct
c) 0.05m²

d) 1/150 of cross sectional area of duct

Answer 33

c) 0.05m² each opening

Ducts between 0.05 and 7.5m²

Question 34

If a pipe passes through a cavity wall what are two key requirements?

Answer 34

1) Be protected against failure caused by movement
2) Escaping gas must not enter the cavity

Question 35

What is the minimum sized joist that you can notch?

Answer 35

Depth = 100mm

Question 36

If you sleeve a pipe what can you seal the end with?

Answer 36

Non-setting mastic