LPG

Question 1

Complete the starter drawing below to show an LPG auto changeover two stage regulator
station to suit the cylinders shown.
Indicate all main components of the flexible cylinder connections with an auto changeover
first stage regulator with separate second stage regulator.

Answer 1

• Slabs.
• 1st and 2nd stage regulators.
• Pigtails.
• Excess flow in pigtails.
• Chains.
• Test point.
• Drip Leg.

Question 2

Two 45 kg exchange cylinders are to be installed on the outside wall of a house. The
customer has requested the cylinders be located below an openable window.
Referring to AS/NZS 5601 Part 1, state the minimum clearance below the window required
for the cylinder valves.

Answer 2

150 mm

Question 3

AS/NZS 5601 Part 1, lists clearances required from LPG cylinders to openings, drains and
doorways.
Name another hazard that LPG cylinders must have clearances from.

Answer 3

• Ignition sources

* Readily ignitable material

Question 4

A changeover regulator which has a 20 mm vent terminal is to be installed on the wall between the two cylinders.
(i) Referring to AS/NZS 5601 Part 1, state the minimum clearance below the window required for the vent terminal.

Answer 4

500 mm

Question 5

State the conditions under which a site Location Certificate is required for LPG.

Answer 5

Over 100 kg of LPG and on site for longer than 18 hours

Question 6

If the clearance in (c) (i) cannot be achieved, give a solution that does not include changing the regulator or altering the window.

Answer 6

Run a vent line from the regulator vent to an acceptable location.

Question 7

Explain why an auto-changeover regulator may switch to the reserve cylinder, while the primary cylinder is still half full.

Answer 7

The cylinder cannot vaporise the liquid LPG fast enough to keep up with the load required from the appliances.

Question 8

Give TWO options that can reduce the chance of the situation in (d)(i) happening.

Answer 8

• Adding more cylinders to cope with the demand.
• Using propane only filled cylinders.
• Heated cylinder jackets.

Question 9

Explain the purpose of Approved Codes of Practice.

Answer 9

To give preferred work practice or arrangements.

Question 10

When a domestic LPG cylinder is filled with liquid LPG, it is permitted to be filled to
85% only.
Give TWO reasons for this.

Answer 10

• To allow room for vaporisation in the cylinder.

* To allow for expansion due to increases in temperature.