QUESTION 9
(a)  If a surcharge is likely to occur regularly in a drainage system, a reflux valve may be
installed. Using your knowledge of AS/NZS 3500 Part 2: Sanitary plumbing and drainage,
state the position where the reflux valve must be installed in each of the following situations.
 (i)  Where the drain has an inspection shaft installed.
 
(1 mark)
 (ii)  Where the drain has a boundary trap.
 
(1 mark)
(b) (i)  Draw and label a reflux valve.
(2 marks)

QUESTION 9 (cont’d)
(ii)  Fully describe the workings of a reflux valve.
(3 marks)
(c)  Drainage pipe and fittings come in several sizes and are constructed of a variety of
materials. Complete the table below by giving two acceptable jointing methods for each
material listed.

PLEASE SEE PDF FOR TABLE

(5 marks)
Total 12 marks

Linkback: https://www.plumbers.nz/drainlaying-exam-june-2008/27/question-9/218/