QUESTION 2
(a)  One of the purposes of a sewer gas interceptor trap is to prevent foreign objects from
entering a sewer. State another purpose.
 
 
(1 mark)
(b)   Describe, in order, the effect on the discharge as it passes through a grease trap. 
 
(3 marks)
(c)  Stormwater drains within and under buildings and main internal drains shall be tested.
 (i)   State the maximum head to which a stormwater drain can be tested during a
hydrostatic test.
 (ii)  State the length of time for which the test should be maintained for any
  material other than vitrified clay.
 (iii)  State what determines that the test has been successful.
 
(3 marks)

(d) From your knowledge of AS/NZS3500: Part 2 Sanitary plumbing and drainage, state the   
 MINIMUM size of the following drain vents.
 
 (i)  The upstream vent on any main drain.
  (ii)  The upstream vent on any branch drain.
 
 (iii)  The section of drain acting as a vent.
(3 marks)
Total 10 marks

Linkback: https://www.plumbers.nz/drainlaying-exam-november-2007/25/question-2/236/

(d) From your knowledge of AS/NZS3500: Part 2 Sanitary plumbing and drainage, state the   
 MINIMUM size of the following drain vents.
 
 (i)  The upstream vent on any main drain. 50mm
  (ii)  The upstream vent on any branch drain. 40mm
 
 (iii)  The section of drain acting as a vent. 65mm
(3 marks)
Total 10 marks