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TABLE 4. 3 DIAMETER OF ROD HANGERS

TABLE 4. 3 DIAMETER OF ROD HANGERS

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51

AS 5601 – 2000
AG 601 – 2000

4.4.3 Requirement where consumer piping is to include cathodic
protection
Where consumer piping is to include cathodic protection, a suitable insulating joint
shall be fitted –
(a)

where the consumer piping emerges from the ground; and

(b)

with a clearance of at least 300 mm from the ground.

NOTE: This requirement applies to all locations where the consumer piping enters or
leaves the ground.

4.4.4 Consumer piping in a corrosive environment
Where a pipe or fitting is to be installed in a corrosive environment the pipe or fitting
shall be protected.
NOTE: The sheathing, coating or wrapping of a pipe or fitting, installing of cathodic
protection, sacrificial anodes or rectifier units, dependent on the situation, will satisfy this
requirement.

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4.4.5 Proving effectiveness of pipe protection
Where consumer piping is to be in the ground and protection is required by
Clause 4.4.3 or Table 3.1, the effectiveness of such protection shall be proved by
recognised methods.

4.4.6 Corrosion protection of uncoated or bare steel pipe
Uncoated or bare steel consumer piping shall be protected against corrosion as
soon as possible after installation and before commissioning by –
(a)

removing oil and grease by the use of a suitable solvent;

(b)

removing loose mill scale and rust; and

(c)

after completion of (a) and (b), applying an adequate paint system which will
provide durable protection.

NOTES:
1 When the pipe surface has been prepared the following is considered an adequate
paint system, provided the piping will not be subjected to harsh environmental
conditions:
(a)
Apply a coat of zinc phosphate iron oxide primer to the piping, (ensure a good
coverage has been obtained).
(b)
After the primer is dry, apply two coats of high gloss external enamel paint.
The first coat is to dry before the second coat is applied.
2 Where harsh environmental conditions exist or regular maintenance of the protection
will be difficult, a higher standard of preparation and protection should be used.

4.5 CONSUMER PIPING GAS PRESSURE REGULATORS
4.5.1 Requirements for a consumer piping gas pressure regulator
A regulator shall be acceptable to the Authority and comply with all of the following:
(a)

Be constructed of material, and use lubricants, suitable for the particular
application.

(b)

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

(c)

Meet the requirements of Clause 4.2.1.

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AS 5601 – 2000
AG 601 – 2000



52

4.5.2 Consumer piping gas pressure regulator installation requirements
A consumer piping gas pressure regulator shall be installed in accordance with all
of the following:
(a)

Above ground unless the Authority permits otherwise.

(b)

In a well-ventilated place.

(c)

Protected from the entry and accumulation of water (eg. sprinkler water,
rainwater etc) and other foreign matter

(d)

Readily accessible for maintenance and adjustment.

(e)

In a place where it will not be subjected to excessive temperature.

(f)

Positioned to minimise the possibility of ignition of any discharge from a
breather vent.
NOTE: For the discharge of a breather vent within an enclosure or room see
Clause 4.7.9.

(g)

Positioned to minimise exposure to physical damage.

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NOTE: Particular attention should be given to the risk of impact from falling ice and
snow, where appropriate.

4.5.3 Prohibited locations for a consumer piping regulator
A consumer piping gas pressure regulator shall not be installed 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)

In a cavity wall.

4.5.4 Where a consumer piping gas pressure regulator is required
A consumer piping gas pressure regulator shall be fitted for any of the following
conditions, as applicable:
(a)

Where any appliance in the premises is not fitted with an appliance gas
pressure regulator.
NOTE: This requirement does not apply where the gas supply or consumer piping
pressure will not exceed 1.5 kPa for Town Gas, TLP and Natural Gas, or 3.5 kPa for
LP Gas.

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(b)

Where the intended operating pressure of the consumer piping exceeds the
rated working pressure of the appliance gas pressure regulator(s).

(c)

Where the gas pressure to a section of consumer piping would otherwise
exceed the rated working pressure of the piping, fittings or components in that
section.

WA 4.5.5 Appendix L

4.5.5 Pressure test points at a consumer piping gas pressure regulator
Pressure test points shall be provided at or near the outlet of any consumer piping
gas pressure regulator.
NOTE: This requirement does not apply to a LP Gas cylinder or tank regulator which is to
have an outlet pressure not exceeding 3.5 kPa.
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53

AS 5601 – 2000
AG 601 – 2000

4.5.6 Consumer piping regulator outlet operating pressure notice
Where the outlet operating pressure setting of a consumer piping gas pressure
regulator for Natural Gas, Town Gas or TLP exceeds 1.5 kPa or for LP Gas
exceeds 3.5 kPa, there shall be a permanent and durable notice in a prominent
position near the regulator showing the outlet pressure setting.
NOTE: Suitable wording for this notice would be:
“THIS REGULATOR OUTLET PRESSURE SETTING IS ____ kPa.”

4.6 PRESSURE PROTECTION


4.6.1 Over-pressure protection and its performance
The following shall be satisfied:
(a)

For gases other than LP Gas;

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Over-pressure protection shall be provided where the operating pressure at
the inlet to a gas pressure regulator –
(i)

exceeds 7 kPa; and also

(ii)

exceeds the fault pressure of piping and components supplied by the
regulator up to and including the next downstream regulator.

The over-pressure protection device shall ensure that piping and components
supplied by the regulator up to and including the next downstream regulator
will not be subjected to a pressure greater than fault pressure.
(b)

For LP Gas;

Over-pressure protection shall be provided where the operating pressure at
the inlet to a gas pressure regulator:
(i)

exceeds 14 kPa; and also

(ii)

exceeds the fault pressure of piping and components supplied by the
regulator up to and including the next downstream regulator.

The over-pressure protection device shall ensure that piping and components
supplied by the regulator up to and including the next downstream regulator
will not be subjected to a pressure greater than 14 kPa, unless the piping and
components can tolerate higher pressures.
NOTES:
1 Where the inlet pressure to an appliance gas pressure regulator will exceed 7 kPa a
consumer piping regulator may be required. Refer to Clause 4.5.4.
2 Refer to Clause 1.4.44 for definition of ‘fault pressure’.

4.6.2 Requirements where over-pressure protection system shuts off
the gas supply
Where an over-pressure protection system is of a type which shuts off the gas
supply, all of the following shall apply:
(a)

The over-pressure protection system is to be of a manual reset type to restore
supply.

(b)

A gas filter that will prevent the passage of foreign particles larger than 1 mm
is to be located upstream and within 5 m of the device that shuts off the gas
supply.

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AS 5601 – 2000
AG 601 – 2000

54

4.6.3 Protection of gas supply system from low pressure where a gas
pressure-raising device or a gas engine is installed
Where a gas pressure -raising device or a gas engine is to be installed, a suitable
low-pressure device shall be installed in the consumer piping as near as practicable
to the inlet of the pressure-raising device or engine. The device shall cut off the
power to the gas pressure-raising device or engine when the inlet pressure falls
below 20% of the operating pressure at the sensing point or 800 Pa, whichever is
the higher.
NOTES:
1 This 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 shut-downs.
2 Such devices include, but are not limited to, a mechanical diaphragm-operated or
electrically-operated diaphragm low-pressure shut-off valve.
3 See also Clause 4.15.3 for additional requirements.

4.7 VENTING

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NOTE: In this Section the term ‘vent terminal’ means a vent opening on a regulator or
similar device having a diaphragm, or the terminal of a vent line.

4.7.1 Performance of vent line
A vent line , under all operating conditions, shall not adversely affect the operation
of the device to which it is connected.

4.7.2 Vent line – Where required
The following shall be fitted with a vent line that terminates outside a building:
(a)

A safety shut-off system which requires venting to atmosphere.

(b)

A gas pressure relief device.
NOTE: This does not apply to a relief device fitted to an LP Gas cylinder.

(c)

A consumer piping gas pressure regulator incorporating a gas pressure relief
device.

(d)

A breather vent except where Clause 4.7.9 or Clause 4.7.10 applies.

4.7.3 Limitation on interconnection of vent lines
Other than permitted by Clauses 4.7.4 and 4.7.5, vent lines shall not be
interconnected.

4.7.4 Restriction on interconnection of breather vent lines
The interconnection of breather vent lines shall be restricted to breather vent lines
from the same appliance .

4.7.5 Restriction on interconnection of vent lines from vented safety
shut-off systems
The interconnection of vent lines from vented safety shut-off systems shall be
restricted to vented safety shut-off systems fitted to the same appliance .

4.7.6 Size of a common vent line
Subject to Clause 4.7.1, a common vent line shall have a cross-sectional area not
less than the sum of the cross-sectional areas of the two largest vent lines being
interconnected.

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55

AS 5601 – 2000
AG 601 – 2000

4.7.7 Size of vent line for a consumer piping gas pressure regulator
breather vent or relief device
Subject to Clause 4.7.1, the minimum size of any vent line for a consumer piping
gas pressure regulator breather vent or a relief device shall be as follows:
(a)

For a vent line not exceeding 10 m in length, the size shall be the vent
connection size.

(b)

For a vent line exceeding 10 m but not exceeding 30 m in length, the size
shall be one standard pipe size larger than the vent connection size.

NOTES:
1 Restrictions due to changes in direction are to be considered in determining vent line
size.
2 A vent line exceeding 30 m in length needs to be designed taking into account the
effects of regulator or relief device inlet pressure, vent line flow resistance and the
duty of the regulator or relief device.

4.7.8 Size of vent line for a vented safety shut-off system

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The size of a vent line for a vented safety shut-off system shall comply with
Table 4.4.
NOTES:
1 Restrictions due to changes in direction are to be considered in determining vent line
size.
2 Where a vent line falls outside the scope of the table, the Authority may require to be
specifically advised prior to the commencement of any work.

TABLE 4.4
VENT PIPE SIZE FOR VENTED SAFETY SHUT-OFF SYSTEMS
Minimum
nominal
size of
vent valve
mm

Maximum length
m
Nominal size of vent line - mm
15

20

25

6

60

160

400

8

30

80

200

10

15

40

100

15

8

20

50

10

25

64

13

32

80

16

40

100

20

50

130

25

65

160

32

80

200

40

100

20
25
32
40
50

NOT

65

APPLICABLE

32

40

80

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50

65

80

100

150

300

AS 5601 – 2000
AG 601 – 2000

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4.7.9 Limitation for discharging a breather vent into a room or
enclosure
A breather vent is permitted to discharge into a room or enclosure when the
diameter of the breather vent orifice does not exceed the maximum value
determined by Appendix G.

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NOTES:
1 The maximum value determined by Appendix G is related to the room or enclosure
size and the gas inlet pressure to the device, and assumes an air change rate of one
room or enclosure volume per hour.
2 The limitation on the breather vent orifice diameter is related to a possible worst case
safety condition of a ruptured diaphragm (or similar membrane) separating the gas
within the device from free air outside the device. The aim of this provision is to
ensure that the accumulation of gas in a room or enclosure, as a result of diaphragm
rupture, will remain below the lower explosive limit (LEL) of the air/gas mixture.
3 Some devices, such as regulators, employ an orifice below the diaphragm, to control
gas flow, and a vent opening above the diaphragm, to permit the regulator to operate
correctly. In the event of a diaphragm rupture in these cases, ‘breather vent orifice’
means the smaller orifice through which gas escapes into a room or enclosure. Care
should therefore be taken to establish whether the internal orifice or the vent of the
device is the smaller.

4.7.10 Restriction of breather vent

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To avoid fitting a vent line to a device having a breather vent, the device may have
a vent restricting orifice fitted to it, provided –
WA 4.7.10 Appendix L

(a)

the orifice does not exceed the maximum value determined by Appendix G;

(b)

such a restriction is approved by the manufacturer of the device or their
representative; and

(c)

the orifice does not, under all operating conditions, adversely affect the
operation of the device.

4.7.11 Vent terminal location
A vent terminal shall be located where gas discharge will dissipate without entering
buildings or creating any hazard. The point of discharge shall –
(a)

be located so there is no ignition source or opening, other than in (b), into a
building within the zone shown in Figure 4.2; and

(b)

be at least 3 m from a mechanical air inlet unless calculations based on
Figure 4.2 give a greater distance; and

(c)

in cases where there is any object (eg wall, ground, etc) in the direction of
discharge and within the exclusion zone of Figure 4.2, be located at least
distance L (of Figure 4.2) in all directions.

NOTE: The requirements of this Clause do not apply to a breather vent terminal. See
Clause 4.5.2(f).

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