Question 5
« on: April 20, 2009, 03:34:35 PM » Quote 

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QUESTION 5
(a) In relation to the pumping of foul water, give the meaning of the term “Duplex pumping system”.
(1 mark) a dual pump system which one pump can operate and the other waiting to be used
(b)  State the minimum diameter for a drain vent in accordance with each of the following
acceptable solutions.
 (i) Acceptable solution G13/AS2 Drainage.   dia 80mm
 (ii) AS/NZS 3500 Part 2: Sanitary plumbing and drainage. dia 50mm
(2 marks)
(c)  When drains are being laid in other than stable ground or where soil movement may 
affect the performance of the drain, the territorial authority requires specific information 
to be supplied.
 (i)  List THREE requirements that the territorial authority will require prior to the
commencement of the laying of drains in these situations.
  1 a plan to give the drain full support and bedding & backfill
  2 any calculations
  3 soil report
(3 marks)
 (ii)  State who must verify the information prior to submission of this information to the
territorial authority. a qualified engineer
(1 mark)

(d)  AS/NZS 3500 Part 2: Sanitary plumbing and drainage states that inspection shafts shall
terminate at or near ground level with a removable air tight inspection cap.
  State THREE important extra installation features a drainlayer must implement to 
comply with this standard where the inspection shaft may be subjected to damage by
vehicular traffic.
 1 covered with a cover/plate suitable to handle vehicals super imposed loadings
 2 the plate needs to be independantly supported and free from putting stress on the riser/shaft
 3 shaft needs to terminate just below the cover
(3 marks)
Total 10 marks