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TABLE 4. 7 VENTILATION FOR CONCEALED PIPING

TABLE 4. 7 VENTILATION FOR CONCEALED PIPING

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65

AS 5601 – 2000
AG 601 – 2000

4.12 INSTALLING PLASTIC PIPING
4.12.1 Marker tape
Marker tape complying with the requirements of AS/NZS 2648 shall be laid above
plastic consumer piping when installed in an open-cut trench.

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NOTES:
1 The marker tape should be approximately 150 mm above the installed pipe.
2 Detectable marker tape may be preferred on large installations eg. schools, factory
complexes, etc.
WA 4.12.2 Appendix L

4.12.2 Termination of plastic pipe and metallic continuation

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Plastic consumer piping shall –
(a)

terminate at least 300 mm underground; and

(b)

the riser shall be of a metallic material which complies with the requirements
of Table 3.1 for underground pipe.

NOTES:
1 The riser is the section of pipe connected to the plastic pipe and which emerges from
the ground.
2 Galvanised steel should not be used with plastic fittings as stress cracking and
degradation of the fitting can occur.

4.12.3 Securing the riser
The riser from buried plastic consumer piping shall be secured such that stress in
the underground pipe is minimised.
NOTES:
1 The riser is the section of pipe connected to the plastic pipe and which emerges from
the ground.
2 Attaching a short length of the plastic pipe material to the riser will assist others in
identifying the buried material at a later date.

4.13 CONSUMER PIPING IN A HIGH RISE BUILDING
NOTES:
1 The Authority may require to be specifically advised prior to the commencement of
the installation of consumer piping in a high rise building.
2 Reference should be made to the applicable building regulations which give
requirements for the construction of fire-rated pipe ducts, and the construction of
plant rooms and enclosures for appliances in high rise buildings.

4.13.1 Plan of consumer piping to be displayed on site
A plan of the consumer piping is to be prominently displayed in the fire control room
or in another location acceptable to the Authority. The plan shall be current and
comply with all of the following:
(a)

Detail the location of all emergency manual shut-off valves.

(b)

Be vermin proof and weatherproof.

4.13.2 Manual shut-off valve in riser and lateral
A manual shut-off valve shall be installed in an accessible position –
(a)

at the gas entry point to each riser where there is more than one riser; and

(b)

in each lateral branch pipe as close as practicable to the main riser.

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AS 5601 – 2000
AG 601 – 2000

66

4.13.3 Support and flexibility of riser
A riser shall comply with the following, as appropriate:
(a)

Have a pipe supporting system that is designed to make allowance for
expansion and contraction.

(b)

Where the riser is inside a building, it is to be sleeved where it passes through
each floor and ceiling slab, with any joint within the sleeve being welded or
brazed.

NOTE: See also Clauses 4.2.5 and 4.3.

4.13.4 Minimising strain at a lateral
Strain at the junction of a lateral and a riser, due to the relative movement between
a riser and the building, shall be minimised.

4.14 SUB-METERS

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NOTE: This Clause gives requirements for the installation of sub-meters only. The
requirements for the consumer billing meter (master meter) are determined by the
appropriate Authority. Some general guidelines regarding the siting of these meters are
given in Appendix A. However, the Authority should be contacted to obtain full details
regarding the siting of the consumer billing meter.

4.14.1 Requirements for a sub-meter
A sub-meter shall be acceptable to the Authority and comply with all of the
following:
(a)

Be constructed of materials, and use lubricants, suitable for all gases.

(b)

Have a capacity suitable for the designed gas load and allowable pressure
drop for the particular application.

4.14.2 Prohibited locations of a sub-meter
A sub-meter shall not be in any of the following locations:
(a)

A lift shaft or lift motor room.

(b)

A room specifically intended for electrical switch gear.

(c)

A fire-isolated stairway or passageway.

(d)

A fire hydrant or hose reel cabinet.

(e)

In such a position that would obstruct egress from a building.

(f)

A bedroom.

(g)

An area where excessive temperatures or sudden excessive changes in
temperature may occur.

(h)

On a floor which is frequently wetted.

(i)

On a floor which contains materials which may corrode the meter.

(j)

On the ground.

(k)

In the foundation area under a building.

(l)

In a cavity wall, except where Clause 4.14.5 applies.

4.14.3 Sub-meter to be readily accessible and identifiable
A sub-meter shall be installed in a readily accessible location which permits ease of
replacement, maintenance and reading, and is to be clearly identified with the gas
installation it supplies.
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AS 5601 – 2000
AG 601 – 2000

4.14.4 Sub-meter to be protected from damage
A sub-meter shall be protected from damage.
NOTE: Includes damage caused by impact, corrosion, heat, excessive vibration, steam
and dampness.

4.14.5 Sub-meter in a recess or meter box in a cavity wall
A recess or meter box in a cavity wall for housing a sub-meter shall comply with the
following:
(a)

Be constructed of non-combustible material.

(b)

Be completely sealed from any adjoining recess or cavity.

(c)

Be of adequate size to permit ease of replacement and maintenance of the
sub-meter.

(d)

Be ventilated directly to outside atmosphere and the required ventilation shall
comply with Clauses 4.16 or 4.17 as appropriate.

4.14.6 Ventilation requirements where in an enclosure

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Where a sub-meter is installed in an enclosure , the enclosure shall be ventilated in
accordance with the requirements of Clauses 4.16 or 4.17 as appropriate.

4.14.7 Provision of manual shut-off valve
A manual shut-off valve shall be provided in the consumer piping upstream of the
sub-meter. The valve shall be accessible for operation and be as close as
practicable to the sub-meter.

4.14.8 Strain on sub-meter connections
A sub-meter shall be supported independently of, and connected to, the consumer
piping in such a way that strain on the sub-meter or connecting piping is minimised.

4.14.9 Connection of the sub-meter
A sub-meter shall be attached to the consumer piping by suitable connections.

4.15 GAS PRESSURE-RAISING DEVICES
NOTE: The Authority may require to be specifically advised prior to the commencement
of the installation of a gas pressure-raising device.

4.15.1 Restriction on installation
The installation of a gas pressure-raising device shall not cause pressure pulsation
which will adversely affect gas equipment or appliances.

4.15.2 Connection requirements
A gas pressure-raising device, which will impart vibration to the consumer piping,
shall be attached to the piping by flexible connections suitable for the application,
fitted to the inlet and outlet of the device.

4.15.3 Required controls
A gas pressure-raising device shall have the following controls on the inlet side in
the sequence given:
(a)

A manual shut-off valve.

(b)

A manual reset type low pressure switch installed between the manual shut-off
valve and the pressure-raising device, which will cut off the power to the
device when the inlet pressure falls below 20% of the operating pressure at
the sensing point or 800 Pa whichever is the higher.
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AS 5601 – 2000
AG 601 – 2000

(c)

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A non-return valve.

NOTE: The low-pressure switch setting in (b) is the minimum allowable figure. The actual
setting should be discussed with the Authority. The setting is to be as high as possible to
provide maximum protection of upstream equipment without causing nuisance shutdowns.

4.15.4 Requirements of downstream pipe and equipment
Piping and equipment downstream of a gas pressure-raising device shall satisfy the
following or over-pressure protection shall be fitted:
(a)

The rated working pressure of the piping and equipment shall not be less than
the maximum working pressure of the gas pressure -raising device.

(b)

The test pressure for the piping and equipment shall not be less than the
highest pressure likely to occur due to equipment failure.

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4.16 VENTILATION OF GAS EQUIPMENT – LIGHTER THAN AIR
GASES
NOTES:
1 Gas equipment in this Clause means a meter, regulator or gas pressure-raising
device.
2 Where natural ventilation is used, all or part of the required ventilation may be
supplied by adventitious openings, (ie. air which ‘leaks’ into an enclosure through
gaps in the structure). To determine the amount of adventitious ventilation available,
2
3
allow 7 cm per m of volume of the space being ventilated.

4.16.1 Ventilation of an enclosure containing a meter or regulator
4.16.1.1 General
Where a meter or a regulator is to be installed in an enclosure , the enclosure
requires ventilation. The enclosure shall be ventilated by one of the methods
detailed in Clauses 4.16.1.2, 4.16.1.3 or 4.16.

4.16.1.2 Natural ventilation direct from outside
Two openings shall be provided directly to outside. The openings shall be located to
ensure the distance between the top of the upper opening and the ceiling of the
enclosure, and the distance between the bottom opening and the floor of the
enclosure does not exceed 5% of the height of the enclosure.
The minimum free ventilation area provided by each opening shall be calculated
using the following formula:
A=

RxF

where –
A=

the minimum free ventilation area (cm2 ).

R=

equipment rated capacity (m3/h).

F=

10 for pressures not exceeding 7 kPa; or
20 for pressures exceeding 7 kPa but not exceeding 200 kPa; or
30 for pressures exceeding 200 kPa but not exceeding 1050 kPa.

NOTES:
1 Where a meter and a regulator are to be installed in an enclosure as part of one
system, the equipment rated capacity is taken as the badge capacity of the meter
3
in m /h at 125 Pa pressure differential. That is, not the sum of the regulator and
meter rated capacities.
2 The pressure used to determine F is the highest operating pressure in the enclosure.
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AS 5601 – 2000
AG 601 – 2000

4.16.1.3 Natural ventilation via adjacent room
The enclosure is to be provided with two openings positioned in accordance with
the requirements of Clause 4.16.1.2.
The free area of each opening shall be twice that required by Clause 4.16.1.2.
These requirements shall apply to all subsequent rooms until a room is ventilated to
outside. That room shall be ventilated in accordance with Clause 4.16.1.2.

4.16.1.4 Mechanical ventilation
Where the ventilation to the enclosure is to be provided by mechanical means, this
shall be directly to outside and the system shall comply with Table 4.8.

4.16.2 Ventilation of an enclosure containing a gas pressure-raising
device
4.16.2.1 General
Where a gas pressure -raising device is to be installed in an enclosure the enclosure
requires ventilation. The enclosure shall be ventilated by one of the methods
detailed in Clauses 4.16.2.2, 4.16.2.3 or 4.16.2.4.

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4.16.2.2 Natural ventilation direct from outside
Two openings shall be provided directly to outside. The openings shall be located to
ensure the distance between the top of the upper opening and the ceiling of the
enclosure, and the distance between the bottom opening and the floor of the
enclosure, does not exceed 5% of the height of the enclosure.
The minimum free ventilation area provided by each opening shall be calculated
using the following formula:
A=

R x 30

where –
A=

the minimum free ventilation area (cm2 ).

R=

equipment rated capacity (m3/h).

4.16.2.3 Natural ventilation via adjacent room
The enclosure is to be provided with two openings positioned in accordance with
the requirements of Clause 4.16.2.2.
The free area of each opening shall be twice that required by Clause 4.16.2.2.
These requirements shall apply to all subsequent rooms until a room is ventilated to
outside. That room shall be ventilated in accordance with Clause 4.16.2.2.

4.16.2.4 Mechanical ventilation
Where the ventilation to the enclosure is to be provided by mechanical means this
shall be directly to outside and the system shall comply with Table 4.8.

4.16.3 Ventilation of an enclosure containing a meter or regulator and
a gas pressure-raising device
Where a meter or regulator and a gas pressure-raising device are to be installed in
the same enclosure , the enclosure shall be ventilated by one of the methods
detailed in Clauses 4.16.1 or 4.16.2. The method used shall be the one which
provides the greater amount of ventilation to the enclosure .

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