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AS 3814:2018


Industrial and commercial gas-fired appliances

Specifies the uniform minimum requirements for the design, construction and safe operation of Type B appliances that are intended for use with town gas, natural gas, simulated natural gas, liquefied petroleum gas and tempered liquefied petroleum gas or any combination of these gases either together or with other fuels.
Published: 25/10/2018
Inclusive of GST
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Table of contents
Cited references
Content history
Table of contents
About this publication
1 Scope and general
1.1 Scope
1.1.1 General
1.1.2 Appliance exclusions
1.2 Application
1.2.1 General
1.2.2 Appliance installation
1.2.3 Conformance
1.2.4 New and alternative materials and methods
1.2.5 Unusual installations
1.2.6 Modification or relocation of an appliance
1.2.7 Non-conformance with requirements in this Standard
1.3 Referenced documents
1.4 Definitions
2 Requirements for design and construction
2.1 General requirements
2.1.1 Appliance design General Risk assessment requirements Improper use
2.1.2 Suitability for application Location Gas quality
2.1.3 Controls and indicating devices
2.1.4 Design of adjustable devices
2.1.5 Appliance to be well constructed
2.1.6 Appliance parts to be secure against accidental displacement
2.1.7 Appliance parts to be secure for satisfactory operation
2.1.8 Appliance to be free of sharp edges
2.1.9 Appliance supports to be of adequate strength
2.1.10 Provision to be made for sampling flue gases
2.2 Controls, burner and safety device access
2.3 Burner flame visibility
2.3.1 Burner flame to be visible to maintenance personnel
2.3.2 Visual indication of burner flame to operator
2.4 Temperatures of surfaces and components
2.5 Restriction on electrical connections
2.5.1 Ease of connection
2.5.2 Limit on cross-connection
2.6 Accessibility of manual controls
2.7 Access for maintenance
2.8 Materials
2.8.1 Materials to be adequate for their intended application
2.8.2 Restriction on use of zinc-base die-castings
2.8.3 Materials to be suitable for gas
2.9 Gas pipework and valve trains
2.9.1 Gas pipework
2.9.2 Flexible hose and connection requirements
2.9.3 Enclosure for a valve train
2.9.4 Pressure rating of valve train components Upstream of and including appliance gas pressure regulator Downstream of appliance gas pressure regulator
2.9.5 Requirements where pressurized air, oxygen or a stand-by gas is to be used
2.9.6 Multi-position manual control valves
2.9.7 Design of valve handles, dials and pointers
2.9.8 Appliance isolating valve Appliance isolating valve to be fitted Requirements for appliance isolating valve Location of appliance isolating valve Identification of appliance isolating valve Connection of appliance isolating valve
2.9.9 Main burner isolation Main burner isolation valve location Main burner isolation for commissioning
2.9.10 Restriction on test firing valve
2.9.11 Pilot burner isolating valve
2.10 Gas pressure regulation
2.10.1 Gas pressure regulator to be fitted
2.10.2 Requirements for a gas pressure regulator
2.10.3 Gas pressure regulator accuracy
2.10.4 Position of gas pressure regulator
2.10.5 Venting of gas pressure regulator
2.11 Gas over-pressure protection
2.11.1 Requirement where over-pressure protection shuts off the gas supply
2.11.2 Where over-pressure protection system is to be fitted
2.11.3 Setting of over-pressure protection system
2.11.4 Location of over-pressure protection system sensing point
2.12 Gas low-pressure protection
2.12.1 Low-gas-pressure detector to be fitted
2.12.2 Requirements of low-gas-pressure detector
2.13 Gas pressure test points
2.13.1 Location of pressure test points
2.13.2 Sealing of a pressure test point
2.13.3 Maximum orifice size of a pressure test point
2.14 Gas filter
2.14.1 Filter to be fitted
2.14.2 Requirements and location of filter
2.15 Safety shut off systems
2.15.1 Safety shut off valve and vent valve
2.15.2 Function of safety shut off system
2.15.3 Safety shut off valve system requirements for main and start gas supplies General Concession for atmospheric burner not exceeding 500 MJ/h Concession for atmospheric burner not exceeding 1 GJ/h Concession for forced or induced draught burner up to 200 MJ/h Concession for forced or induced draught burner up to 1 GJ/h Concession for a main burner up to 1 GJ/h igniting at low rate Concession for a main burner up to 1 GJ/h with no start gas line Concession for a burner using a separate start gas line Provision for start gas to be taken from between safety shut off valves for a main burner directly ignited at a low rate
2.15.4 Energizing of automatic safety shut off valves
2.15.5 Ignition of main burner by separate pilot
2.15.6 Requirements for a safety shut off valve and vent valve Rated working pressure Orientation Size of vent valve for a double block and vent safety shut off system or an emergency isolation and vent system Size of vent valve for a double block and vent safety shut off system Size of vent valve for an emergency isolation and vent system Size of vent valve for a leakage detection system Arrangement for manual reset vent valve
2.15.7 Safety shut off system not to be bypassed
2.15.8 Vent line requirement
2.15.9 Requirements for a position-proving system Safety shut off valve Vent valve Position-proving system to be interlocked to prevent burner start-up Alarm interlock
2.15.10 Requirements for a leakage detection system Conformity with Standard Leakage detection system to be interlocked to cause lockout Commencement of leakage detection test Maximum allowable leakage rate Leakage detection system that uses gas at line pressure
2.15.11 Function of interlocks
2.15.12 Requirements of safety shut off system actuators Individual actuators to be fitted Single three-way valve permitted Use of rigidly coupled actuators
2.16 Combustion air supply—General requirements
2.16.1 Combustion air supply equipment to be correctly sized
2.16.2 Combustion air quality
2.16.3 Air openings to be of adequate size
2.16.4 Air openings not to be obstructed
2.17 Combustion air for atmospheric burners
2.17.1 Primary aeration controls to be corrosion-resistant
2.17.2 Effect of foreign matter on primary aeration controls to be minimal
2.18 Forced and induced draught burners
2.18.1 Draught characteristics to be specified by the burner OEM
2.18.2 Proving air flow
2.18.3 Self-check of air flow proving device Self-check to be carried out Failure of air flow proving device during self-check
2.18.4 Safety shutdown to occur if air flow fails
2.18.5 Air-gas mixtures Air-gas mixing machines and mixing blowers Maximum temperature of mixtures
2.19 Dampers
2.19.1 Requirements for a fixed or adjustable damper
2.19.2 Requirements for an automatic damper control system Automatic damper to maintain satisfactory burner combustion Failure of damper mechanism
2.19.3 Manual damper control
2.20 Appliance pre-purging
2.20.1 General requirements Function of pre-purge Appliance or process to be pre-purged Pre-purging using an inert medium Supply of inert purging medium to be proved
2.20.2 Pre-purging by mechanical means Mechanical pre-purging required under certain conditions Conduct of mechanical pre-purge
2.20.3 Pre-purging using natural draught Requirements for an appliance using natural draught Pre-purge period using natural draught Pre-purge period included in operating instructions Pre-purge where appliance doors are opened
2.20.4 Pre-purge timer
2.20.5 Pre-purge interlocks Purge flow proving device to be fitted Self-check of purge flow proving device Purging to cease if purge flow fails Pre-purge to reset when purge flow is re-established Proof of operation of zone circulation fans in appliances
2.21 Process controls
2.21.1 Requirements where appliance safety depends on process
2.21.2 Process limit device to cause lockout
2.21.3 Requirements where appliance safety and operation depend on flow
2.21.4 Provision of over temperature protection on recirculation fans
2.22 Ignition systems
2.22.1 Ignition to be safe, reliable and smooth
2.22.2 Manual ignition systems Requirements for a manually-inserted gas torch Point of ignition to be accessible Explosion relief to be provided for a manually-ignited main burner
2.23 Pilot burners
2.23.1 Requirements for a pilot burner with a single main burner
2.23.2 Requirements for supervised pilot burners with multiple main burners
2.23.3 Flames to travel freely to all ports of a multi-port pilot
2.23.4 Bleed lines not to affect ignition of main burner
2.23.5 Protection from blockage
2.24 Main burners
2.24.1 Ignition to be in combustion chamber
2.24.2 Main burners subdivided into zones or sections
2.24.3 Requirements for a burner that can be retracted or swivelled
2.24.4 Requirements for cross-ignition
2.24.5 Protection from blockage
2.25 Flame safeguard systems
2.25.1 Requirements for a flame safeguard system
2.25.2 Flame safeguard system to be fitted
2.25.3 Flame safeguard to conform with classification
2.25.4 Maximum hold-time for a thermoelectric flame safeguard
2.25.5 Maximum shut off time following flame failure
2.25.6 Requirements for a flame detector
2.25.7 Flame simulation to be prevented
2.25.8 Detector not to detect other flame
2.25.9 Requirements for a pilot used on atmospheric burner(s) exceeding 1 GJ/h (275 kW) or forced or induced draught burner(s)
2.25.10 Detectors to supervise separate flames
2.25.11 Requirements for two flame detectors used with one flame safeguard device or system
2.25.12 Detector to ensure cross lighting is complete
2.25.13 Requirements for flame safeguards incorporating hot surface igniters
2.26 Bleed lines
2.26.1 General requirements for a bleed line termination
2.26.2 Terminating bleed lines in a combustion chamber Combustion chamber to have a supervised burner Bleed line requirements Bleed line termination to be protected against blockage
2.27 Appliance/burner controls and safety instrumented systems
2.27.1 Gas-actuated controls
2.27.2 Basic control systems
2.27.3 Safety systems
2.27.4 Burner management systems using a PES
2.27.5 Separated basic control systems and safety instrumented systems using a PES General Requirements of safety instrumented systems (SIS)
2.27.6 Type B appliance documentation guidelines for regulatory acceptance
2.28 Gas/air ratio control
2.28.1 General requirements
2.28.2 Interference with interlocks
2.28.3 Variation in control settings and control response
2.28.4 Preheated combustion air control
2.28.5 Requirements for independent gas and air control elements
2.28.6 Special requirements for PES based gas/air ratio control system
2.28.7 Additional requirements for pneumatically controlled gas/air ratio
2.28.8 Gas/air ratio controls incorporating variable speed drive systems
2.28.9 Use of oxygen sensing probes
3 Operation
3.1 Appliance operation details
3.2 Ignition
3.2.1 Starting sequence interlocks before starting burner ignition source
3.2.2 Burner ignition sequence Commencement of ignition Completion of ignition Start gas flame establishment period
3.2.3 Burner start gas rate
3.3 Main burners
3.3.1 Start flame proving period
3.3.2 Main flame establishment period
3.3.3 Main burner supervision Interrupted pilot Intermittent or permanent pilot with a forced or induced draught burner or atmospheric burner exceeding 1 GJ/h (275 kW)
3.3.4 Main burner to start at reduced rate
3.4 Interlocks and limit devices
3.4.1 Interlocks and limit devices not to be rendered ineffective General Where an interlock is to be fitted Interlocks and limit devices to be tested Requirements for an interlock
3.4.2 Limit devices Limit device to be fitted Limit device not to be an operating control Requirements for a limit device
3.5 Operation sequences
3.5.1 Ignition sequence after power interruption
3.5.2 Programmed sequence for automatic or part automatic burner
3.5.3 Appliance to be left in safe condition
3.5.4 Requirement for lockout on flame failure
3.5.5 Automatic reignition attempt on flame failure Requirements for forced or induced draught burners Requirements for atmospheric burners
3.6 Combustion conditions
3.6.1 Burners to maintain satisfactory combustion conditions
3.6.2 Leakage of combustion products to be prevented
3.7 Commissioning
3.7.1 General
3.7.2 Commissioning checks to be carried out
4 Markings and instructions
4.1 Markings
4.1.1 Markings to be displayed
4.1.2 Marking of controls, dials and gauges
4.1.3 Controls with non-standard operation
4.2 Instructions
4.2.1 Written instructions to be provided
4.2.2 Instructions for operation
4.2.3 Limits of safe operation to be specified
4.2.4 Training
5 Special application requirements
5.1 General
5.2 High input gas-fired appliances
5.2.1 General
5.2.2 Start-up where multiple main burners are fitted
5.2.3 Manual ignition where multiple main burners are fitted
5.2.4 Automatic ignition where multiple main burners are fitted
5.2.5 Burner control
5.2.6 Flame safeguards
5.3 Air-gas mixing machines and mixing blowers
5.3.1 General
5.3.2 Materials
5.3.3 Strength of pipe and fittings
5.3.4 Safety shut off system to be fitted
5.3.5 Safety shut off system to cause lockout
5.3.6 Air-gas ratio Locking provision for air-gas ratio from a mixing machine Limiting provision for air-gas ratio from a mixing machine Air-gas ratio from a mixing blower
5.3.7 Mixing blower outlets
5.3.8 Flashback requirements for air-gas mixing machines
5.3.9 Rupture of blow-out disc
5.3.10 Flame arrestor between air-gas mixing machine and burner
5.3.11 Flame arrestor at mixing machine
5.3.12 Flame arrestors
5.3.13 Air-gas mixing machines—Requirement for non-return valve
5.4 Special atmospheres and atmosphere generators
5.4.1 General
5.4.2 Piping for special atmospheres
5.4.3 Storage of special atmosphere
5.4.4 Storage container for compressed special atmosphere
5.4.5 Venting and disposal of special atmospheres
5.4.6 Discharge using a vent line
5.4.7 Start-up of an atmosphere generator
5.4.8 Ignition
5.4.9 Requirement where the air-gas ratio is variable
5.4.10 Requirements where the air-gas ratio is fixed
5.4.11 Automatic relief device
5.4.12 Flame arrestor
5.4.13 Water-cooled equipment
5.4.14 Exothermic atmosphere generators Flame safeguard requirement Flame safeguard bypass Pressure detectors to be fitted Pressure detectors to be interlocked Interlocking combustible atmosphere flow Purging Air-gas ratio control
5.4.15 Endothermic atmosphere generators Safety shut off valves to be fitted Air shut off device Pressure detectors
5.5 Process after-burners
5.5.1 General
5.5.2 Control of process products Requirement for interlocks Process products—Percentage of LEL
5.5.3 Combustion air supply
5.5.4 Shutting down of process afterburner
5.5.5 Pre-purge
5.6 Steam and hot water boilers
5.7 Direct-fired air heaters and curtains
5.7.1 General
5.7.2 Heater air supply
5.7.3 Air flow sensing device
5.7.4 Pre-purge
5.7.5 Temperature limit device
5.7.6 Start gas rate
5.7.7 Combustion Limits for combustion products Samples of heated air to be taken Limitation on air temperature Combustion at minimum air flow
5.7.8 Markings Marking plate to be fitted Restriction on installation
5.8 Stationary gas engines and turbines
5.8.1 General
5.8.2 Requirement for safety shut off valve system Safety shut off system to be fitted Concessions for gas valve trains on gas turbines and gas engines Safety shut off valves and vent valves Emergency isolation and vent valves Activation of the safety shut off system to shut off gas supply
5.8.3 Gas turbine and gas engine purging Gas turbine purging Gas engine purging Heat recovery systems Air flow proving Gas turbine purge credit General Gaseous fuels with position proving Gaseous fuels with pressurized pipe section Liquid fuels with pressurized pipe section where used with gas fuelled systems Inert liquid
5.8.4 Gas supply flexible connection
5.8.5 Exhaust system to be fitted
5.8.6 Flexible connection to be fitted to exhaust line
5.8.7 Requirements of an exhaust system
5.8.8 Exhaust terminal location
5.8.9 Ventilation of gas engine and gas turbine installations
5.8.10 Requirements for ignition
5.8.11 Gas turbine extinction safety time
5.8.12 Gas turbine indirect flame monitoring
5.8.13 Emergency stop
5.8.14 Overspeed
5.8.15 Gas engine and gas turbine air/fuel ratio control
5.9 Incinerators and cremators
5.9.1 General
5.9.2 Primary burner interlock
5.9.3 Combustion air
5.9.4 Pre-purge
5.9.5 Flues Flues not to be interconnected Limiting updraught
5.10 Rotary process equipment and ovens—Direct-fired
5.10.1 General
5.10.2 Purging
5.10.3 Provision of air General Air flow Recirculation of process air Spray booth oven comfort heating
5.10.4 Explosion relief
5.10.5 Temperature limit device
5.10.6 Access for cleaning
5.10.7 Processes with solvents or combustible dust Provision of dilution air Recirculation air fans Monitoring of solvent LEL
5.11 Smoke ovens—Direct-fired
5.11.1 Lighting torch
5.11.2 Combustion air Combustion air to be provided from outside of oven Restrictions on the use of ducting Smoke not to interfere with combustion
5.11.3 Explosion relief requirements
5.11.4 Loading doors
5.11.5 Sawdust trays
5.11.6 Flue Minimum requirements for natural draught flue Flue damper
5.12 Water heaters
5.12.1 General
5.12.2 Thermostat
5.12.3 Over-temperature control Over-temperature cut-out device to be fitted Over-temperature cut-out to initiate lockout
5.12.4 Unvented water heaters Relief valve to be fitted Location of relief valves Heaters containing 1 L of water or less
5.12.5 Provision for draining
5.13 Multi-fuel firing systems
5.13.1 Alternative multi-fuel systems Isolation of alternative fuel supply Alternative fuel system to be interlocked Fuel lines to be sealed on disconnection
5.13.2 Multi-fuel simultaneous firing systems Maximum operating input Combustion air requirement
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
F1 General
F2 Definition of gas/air ratio control programmable electronic systems
F3 Parameterizable systems that do not require a low oxygen limit device
F4 Parameterizable systems that require a low oxygen limit
F5 PES gas/air ratio control systems
F6 Additional requirements for burner management systems fitted with low oxygen limit device
F6.1 The oxygen probe that could act as an ignition source
F6.2 The oxygen probe that does not act as an ignition source
F7 Multiple burner installations
Appendix G
G1 General
G2 Regular testing
G3 Personnel and organization
G4 General outline of procedures
G5 Testing schedules
Appendix H
Appendix I
I1 Scope
I2 Stage 1: Preliminary inspection
I3 Stage 2: Activation—Run without fuel
I4 Stage 3: Activation—Run with fuel
I5 Stage 4: Operation
I6 Stage 5: Completion
Appendix J
Appendix K
K1 General
K2 Example qualitative risk assessment
K3 Guideline example
Appendix L
Appendix M
Appendix N
Appendix O
O1 General
O2 Need for a fitness-for-purpose assessment
O3 Approach
O4 Explosion, fire, asphyxiation and catastrophic failure
O5 Non-conformance with requirements of this Standard
O6 Independent reference
O7 Contents of the fitness for purpose assessment
O7.1 General
O7.2 Scope
O7.3 Appliance, component, equipment, its installation and its application
O7.3.1 Description
O7.3.2 Function of the appliance or component and its installation including the location
O7.3.3 Original equipment manufacturer’s specifications
O7.3.4 Standards conformity
O7.3.5 Documents
O7.3.6 Product sample
O7.3.7 Appliance, component or equipment and its installation nameplate
O7.4 Training of personnel
O7.5 Elements of the report
O8 Assessor requirements
Appendix P
P1 General
P2 Biogas conditioning systems
P3 Biogas extraction systems
P4 Flare systems
P4.1 General
P4.2 Hazards
P4.3 Safety
P5 Enclosed flares
P6 Flare clearances and location
Cited references in this standard
Electrical installations (known as the Australian/New Zealand Wiring Rules)
ANSI UL 6200
Controls for stationary engine driven assemblies
ANSI UL 2200
Stationary engine generator assemblies
ANSI UL 1998
Software in programmable components
ANSI Z21.21/CSA 6.5
Automatic valves for gas appliances
Content history
DR AS 3814:2017