QUESTION 1
(a)   To comply with NZS 3604, state THREE conditions that determine the position and size of
a hole to be drilled through a wooden floor joist for a gas pipe.
 1
 
 2
 
 3
 
 
(3 marks)
(b)   To comply with NZS 5261, state SIX conditions that must be met when a gas pipe is
embedded directly within a concrete floor slab.
 1
 
 2
 
 3
 
 4
 
 5
 
 6
 
 
(6 marks)

( c)   To comply with NZS 5261, state THREE requirements for an underground gas pipe that
passes through the outer wall of a building. 
 1
 2
 3
(3 marks)
(d)   List FOUR types of fittings that are unsuitable for joining gas installation pipes, as specified
in NZS 5261.
 1
 2
 3
 4
(2 marks)
(e)   Why must the gas velocity be restricted in gas pipework?
 
 
 
(1 mark)
Total 15 marks


Linkback: https://www.plumbers.nz/gas-exam-june-2007/21/question-1/131/

Question 1 (b)

1. The operating pressure shall not exceed 7 Kpa
2. The amount of cover shall be adequate for the particular application
3. The piping shall be plastic-coated or covered in a proprietary wrapping
4. Joints and fittings shall be kept to a minimum and be brazed and then covered in a proprietary wrapping
5. Piping shall be placed so that cutting, bending or displacement of any reinforcement from its proper location is not necessary
6. Piping in a floor shall be placed between the top and bottom reinforcement
7. The size of piping shall not reduce the design strength of the concrete slab
8. Piping shall not extend through expansion joints in the concrete   

Question 1 (d)

1. Croxed joints
2. Plain nipples, e.g. running nipple with parallel threads
3. Compression fittings with non-metallic olives
4. Compression fittings with metallic olives if not approved by the manufacturer for use with gas
5. Longscrew connectors
6. Internally threaded PVC-U fittings unless manufactured with a reinforcing metal band.