THIRD SCHEDULE(Regulation 37)DESIGN OF PIPE LINE COMPONENTSScope3.1 This Schedule prescribes the minimum requirements for the design and installation of pipeline components and facilities and additionally prescribes requirements relating to the protection against accidental over pressuring.General requirements3.2 Each component of a pipeline must be able to withstand an operating pressure and other anticipated loading without the impairment of its serviceability with unit stress equivalent to that permitted for pipe of comparable material in the same location and kind of service.3.3 Despite paragraph 3.2, if a design based on unit stress is impractical for a particular component, the design shall be based on a pressure rating established by the manufacturer after pressure testing that component or a prototype of that component.Qualifying metallic components3.4 Despite any requirement of this Schedule which incorporates by reference an edition of a standard listed in the Fifteenth Schedule, a metallic component manufactured in accordance with any other edition of that standard is qualified for use in this Schedule, if(a) it can be shown through visual inspection of the cleaned component that no defect exists which might impair the strength and tightness of the component; and(b) the edition of the standard under which the component was manufactured has equal or more stringent requirements for the following(i) pressure testing,(ii) materials, and(iii) pressure and temperature ratings.Valves3.5 Except for a cast iron valve and plastic valve, each valve shall meet the minimum requirements specified in Part A of the Fifteenth Schedule, or any other international standard that provides an equivalent performance level.3.6 A person shall not use a valve under any operating condition that exceeds the applicable pressure-temperature ratings contained in the minimum requirements provided in Part A of the Fifteenth Schedule.3.7 A person shall use cast iron and a plastic valve in accordance with the following conditions:(a) the cast iron or plastic valve shall have a minimum service pressure rating for a temperature that is equivalent to or that exceeds the maximum service temperature,(b) the cast iron or a plastic valve shall be tested as part of the following manufacturing processes:(i) with the valve in a fully open position, the shell shall be tested to a pressure of not less than 1.5 times the maximum service pressure rating,(ii) the seat shall be tested, after the shell test, to a pressure not exceeding 1.5 times the maximum service pressure rating,(iii) the test pressure during the seat test shall be applied successively on each side of the closed valve with the opposite side open and there shall be no visible leaks, except in the case of a swing check valve, and(iv) after the last pressure test is completed, the valve shall be operated at its maximum to demonstrate freedom from interference.3.8 Each valve must be able to meet the anticipated operating conditions.3.9 A person shall not use a valve that has a shell component that exceeds 80% of the pressure rating for a comparable steel valve at the listed temperature.3.10 Despite paragraph 3.9, a person may use a valve with its shell components made of ductile iron up to 80% of the pressure rating for the comparable steel valve if(a) the temperature-adjusted service pressure does not exceed 6.90 megapascals gauge; and(b) welding is not used on any ductile iron component in the fabrication of the valve shell or other assembly.3.11 A valve that has any pressure that contains a part made of ductile iron shall not be used in the gas pipe component of a compressor station.Flanges and flange accessories3.12 Except in the case of cast iron, each flange or flange accessory shall meet the minimum requirements of the standards specified in Part A of the Fifteenth Schedule, or its equivalent3.13 A flange assembly shall be of a capacity to be able to withstand the maximum pressure at which the pipeline is to be operated and to maintain its physical and chemical properties at any temperature to which it is anticipated that it might be subjected while in service.3.14 A flange on a flanged joint used in cast iron pipe shall(a) be of the dimension, drilling, face and gasket design in compliance with the standards specified in Part A of the Fifteenth Schedule, and(b) be cast integrally with the pipe, valve or fitting.Standard fittings3.15 The minimum metal thickness of a threaded fitting shall not be less than the applicable standards specified in this Schedule or other equivalent standards.3.16 A steel butt-welding fitting shall have a pressure and temperature rating based on stress for pipe of the same equivalent material.3.17 The actual bursting strength of a fitting shall(a) be equivalent to the bursting strength of pipe and wall thickness of designated material and as determined by any prototype that has been tested to at least the pressure required for the pipeline to which it is being added, and (b) have the equivalent pressure of the pipeline to which the fitting is being added.Passage of internal inspection devices3.18 Subject to paragraphs 3.19 to 3.22, a person shall design and construct each new transmission line and replacement of each pipeline, valve, fitting or other line component in a transmission line to accommodate the passage of any instrumented internal inspection device.3.19 Paragraph 3.18 does not apply to the following:(a) a manifold,(b) a station piping at a compressor station, meter station, or regulator station,(c) any piping associated with a storage facility, other than a continuous run of a transmission line between a compressor station and a storage facility, (d) a cross-over,(e) any size of pipe for which an instrumented internal inspection device is not commercially available,(f) any transmission line that is operated in conjunction with a distribution system which is installed in a Class 4 location,(g) an offshore transmission line, with the exception of a transmission line with an outside diameter of 273 millimetres or more that runs from platform to platform or platform to shore unless(i) the platform space or configuration is incompatible with the launch or retrieving instrumented internal inspection device; or(ii) the design includes a tap for a lateral connection, which the operator can demonstrate is based on investigation or experience, and that there is no reasonably practical alternative under the design in circumstances where the use of a tap is likely to obstruct the passage of an instrumented internal inspection device, and(h) piping that, the Commission or its representative finds in a particular case would be impractical to design and construct to accommodate the passage of an instrumented internal inspection device.3.20 An operator that encounters an emergency or construction time constraint other than an unforeseen construction problem is not required to construct a new or replacement segment of a transmission line in accordance with paragraph 3.18 if that operator documents why the impracticality prohibits compliance with paragraph 3.18.3.21 The operator shall seek the approval of the Commission for the design and construction of a pipeline to accommodate the passage of any instrumented internal inspection device within fourteen days after discovering the emergency or construction problem.3.22 If the Commission refuses to grant approval, the operator shall within one year of the refusal modify the relevant segment of the pipeline in accordance with the directive of the Commission to allow the passage of the instrumented internal inspection device.Tapping3.23 Each mechanical fitting used to make a hot tap, shall be of a design that is at least equivalent to the operating pressure of the pipeline.3.24 Where a person taps a ductile pipe the extent of the use of a full thread engagement and the need for the use of an outside-sealing service connection, tapping saddle or other fixture shall be determined by service conditions.3.25 Where a threaded tap is made in cast iron or ductile iron pipe, the diameter of the tapped hole shall not be more than 25% of the nominal diameter of the pipe unless the pipe is reinforced, except that(a) an existing tap may be used for replacement service, if it is free of any crack and has a good thread; and(b) a 32 millimetre tap may be made in a 102 millimetre cast iron or ductile iron pipe, without reinforcement.3.26 Despite paragraph 3.23 to 3.25, a person may use an unreinforced tap on a pipe of 152 millimetres or larger, in an area where climate, soil and service conditions may create unusual external stress on a cast iron pipe.Components fabricated by welding3.27 Except for a branch connection and assembly of a standard pipe and fitting joined by a circumferential weld, the design pressure of each component fabricated by welding of which the strength cannot be determined shall be established in accordance with the requirements provided in Part A of the Fifteenth Schedule.3.28 A prefabricated unit that uses plate and longitudinal seams shall be designed, constructed and tested in accordance with the requirements provided in Part A of the Fifteenth Schedule, except for the following:(a) a regularly manufactured butt-welding fitting;(b) a pipe that has been produced and tested under a specification listed in Part A of the Fifteenth Schedule;(c) a partial assembly like a split ring or collar; and(d) a prefabricated unit that the manufacturer certifies has been tested to at least twice the maximum pressure to which it will be subjected under the anticipated operating condition.3.29 A person shall not use an orange-peel bull plug or an orange-peel swage on a pipeline that is to operate at a hoop stress of 20% or more of the specified minimum yield strength of the pipe.3.30 Except for a flat closure designed in accordance with the requirements provided in Part A of the Fifteenth Schedule, a person shall not use a flat closure or fish tail on a pipe that operates at 689 kPa gauge, or more, or that is more than 76 millimetres in nominal diameter.Welded branch connection3.31 A person shall design a welded branch connection for a pipe in the form of a single connection, or in a header or manifold as a series of connections, to ensure that the strength of the pipeline system is not reduced, taking into account(a) the stresses in the remaining pipe wall due to the opening in the pipe or header;(b) the shear stresses produced by the pressure acting on the area of the branch opening; and(c) any external loading due to(i) thermal movement,(ii) weight, and(iii) vibration.Extruded outlet3.32 An extruded outlet shall be suitable for an anticipated service condition and shall be at least equal to the design strength of the pipe and other fitting in the pipeline to which it is attached.Flexibility3.33 A person shall design a pipeline with enough flexibility to prevent (a) thermal expansion or contraction from causing excessive stress in the pipe or its components,(b) excessive bending or an unusual load at a joint, or(c) any undesirable force or movement at a point of connection to the equipment, or at anchorage or guide point.Supports and anchors3.34 A pipeline and its associated equipment shall have enough anchor or support to(a) prevent undue strain on connected equipment,(b) resist any longitudinal force caused by a bend or offset in the pipe; and(c) prevent or damp out excessive vibration.3.35 An operator shall provide an exposed pipeline with sufficient support or anchor to protect any exposed pipe joint from the maximum end force caused by internal pressure and any additional force caused by temperature, expansion or contraction or by the weight of the pipe and its contents.3.36 A person shall make a support or anchor on an exposed pipeline made of durable non-combustible material and design and install it as follows:(a) the free expansion and contraction of the pipeline between any support or anchor shall be restricted,(b) make provision for the service conditions involved, and(c) ensure that the movement of the pipeline does not cause disengagement of the support equipment.3.37 The support on an exposed pipeline operated at a stress level of 50% or more of the specified minimum yield strength shall(a) not have a structural support welded directly onto the pipe,(b) have a support that is provided by a member which completely encircles the pipe, and(c) have a weld that is continuous and covers the entire circumference to cater for an encircling member welded to a pipe.3.38 An underground pipeline which is connected to a relatively unyielding line or other fixed object shall have enough flexibility to provide for possible movement, or it must have an anchor which will limit the movement of the pipeline.3.39 Except for an offshore pipeline, each underground pipeline which is being connected to a new branch shall have a firm foundation for both the header and the branch to prevent detrimental lateral and vertical movement.Location of compressor building3.40 Each main compressor or building of a compressor station, except for a compressor building on a platform located offshore or within navigable waters shall be(a) located on property within the control of the operator, and(b) located far away from adjacent property which is not within the control of the operator, to minimise the possibility of the spread of fire to the compressor building from any structure on adjacent property.Building on compressor station site3.41 A building on a compressor station site shall be made of a non-combustible material if it contains either(a) a pipe of more than 51millimetres in diameter which is carrying gas under pressure; or(b) gas handling equipment other than gas utilisation equipment used for domestic purposes.Exits3.42 The operating floor of a main compressor building shall have at least two separate and unobstructed exits so as to provide a convenient and unobstructed passage of escape and each door on the operating floor of a main compressor building shall have(a) a latch that can readily be opened from the inside without a key, or(b) a swing latch embedded in an exterior wall and mounted to swing outward.Fenced area3.43 A fence around a compressor station shall have at least two gates to provide(a) a convenient opportunity for escape to a place of safety, or(b) a facility which affords a convenient exit from the area.3.44 Each gate located within 60.96 metres of any compressor plant building shall be designed to(a) open outward, or(b) open from the inside without a key when occupied.Electrical facilities3.45 A person who installs any electrical equipment and wiring in a compressor station shall comply with Regulations in respect of wiring.Liquid removal at compressor stations3.46 Where entrained vapour in gas may liquefy under the anticipated pressure and temperature condition, the compressor must be protected against the introduction of the liquid in any quantity which could cause damage.3.47 Each liquid separator used to remove entrained liquid at a compressor station shall(a) have a manually operable means of removing these liquids; or(b) have either(i) automatic liquid removal facilities, (ii) an automatic compressor shutdown device, or (iii) a high liquid level alarmwhere slugs of liquid could be carried into the compressors;and(c) be manufactured in accordance with the requirements specified in the Fifteenth Schedule, except that a liquid separator constructed of pipe and fittings without internal welding shall be fabricated with a design factor of 0.4, or less.Emergency shutdown of compressor stations3.48 Except for an unattended field compressor station of 746.70 kilowatts or less, each compressor station shall have an emergency shutdown system that(a) is able to block gas out of the station and blow down the station piping,(b) can discharge gas from the blowdown piping at a location where the gas will not create a hazard,(c) can provide a means for the shutdown of a gas compressing equipment, gas fire and electrical facility in the vicinity of a gas header and in the compressor building, except that(i) any electrical circuit which supplies emergency lighting required to assist station personnel in evacuating the compressor building and the area in the vicinity of the gas header shall remain energised, and(ii) any electrical circuit required to protect equipment from damage shall remain energised,(d) is operable from at least two locations, each of which shall be(i) outside the gas area,(ii) near the exit gates, if the station is fenced, or near an emergency exit, if not fenced; and.(iii) not more than 152 metres from the boundaries of the station.3.49 If a compressor station supplies gas directly to a distribution system with no other adequate source of gas available, the emergency shutdown system shall be designed so that it will not function at the wrong time and cause an unintended outage on the distribution system.3.50 The emergency shutdown system on a platform located offshore or within inland navigable waters shall be designed and installed to actuate automatically by each of the following events:(a) in the case of an unattended compressor station.(i) when the gas pressure increases to 15% above the maximum allowable operating pressure, or(ii) when an uncontrolled fire occurs on the platform; and(b) in the case of a compressor station building(i) when an uncontrolled fire occurs in the building, or(ii) when the concentration of gas in the air increases to 50% or more of the lower explosive limit in a building which has a source of ignition.3.51 For the purpose of paragraph 3.50 (b) (ii), an electrical facility, which meets the requirements in respect of wiring, is not a source of ignition.Pressure limiting devices of compressor stations3.52 A compressor station shall have a pressure relief or other suitable protective device of sufficient capacity and sensitivity to ensure that the maximum allowable operating pressure of the station piping and equipment is not exceeded by more than 10%.3.53 Each vent line which exhausts the pressure relief valve of a compressor station shall extend to a location where the gas may be discharged without hazard.Additional safety equipment for compressor stations3.54 A compressor station shall have adequate fire protection facilities and where fire pumps are a part of these facilities, their operation shall not be affected by the emergency shutdown system.3.55 A compressor station prime mover, other than an electrical induction or synchronous motor, shall have an automatic device to shut down the unit before the speed of either the prime mover or the driven unit exceeds a maximum safe speed.3.56 A compressor unit in a compressor station must have a shutdown or alarm device which can operate in the event of inadequate cooling or lubrication of the unit.3.57 A compressor station of a gas station engine which operates with a pressure gas injection shall be equipped so that stoppage of the engine automatically shuts off the fuel and vents the engine distribution manifold.3.58 Each muffler for a gas engine in a compressor station shall have a vent slot or a hole in the baffles of each compartment to prevent gas from being trapped in the muffler.Ventilation of compressor stations3.59 A compressor station building shall be ventilated to ensure that the employees concerned are not endangered by the accumulation of gas in any room, sump, pit, or other enclosed place.Pipe-type and bottle-type holders3.60 A person that uses a pipe-type or bottle-type holder shall ensure that it is of a design that can prevent the accumulation of liquid in the holder, the connecting pipe or in auxiliary equipment, which might cause corrosion or interfere with the safe operation of the holder.3.61 A pipe-type or bottle-type holder shall have minimum clearance from any other holder in accordance with the following formula:C = (D x P x F)/48.33) (C= (3D x P x F /1,000))whereC = minimum clearance between pipe containers or bottles in millimetre.D = outside diameter of pipe containers or bottles in millimetre.P = maximum allowable operating pressure, pascal gauge.F = design factor as set forth in paragraph 2.11 to 2.14 of the Second Schedule.Additional provisions for bottle-type holders3.62 A bottle-type holder shall be(a) located on a site surrounded entirely by fencing which prevents access by unauthorised persons and with minimum clearance from the fence as follows Maximum allowable operating pressure        Minimum clearance in metres        Less than 7 megapascals gauge7 megapascals gauge or more        830        (b) designed using the design factors set forth in paragraphs 2.11 to 2.14 of the Second Schedule; and(c) buried with a minimum cover in accordance with paragraphs 6.36 to 6.40 of the Sixth Schedule.3.63 A bottle-type holder that is manufactured from steel and which is not weldable under field conditions shall meet the following requirements:(a) the chemical and tensile requirements for the various grades of steel specified in Part A of the Fifteenth Schedule, if that bottle type holder is made from alloy steel,(b) the actual yield-tensile ratio of steel shall not exceed the design factor of 0.85,(c) the welding shall not be performed on the holder after it has been heated treated or stress relieved, except that a copper wire may be attached to the small diameter portion of the bottle end closure for cathodic protection if a localised thermit welding process is used,(d) the holder shall be given a mill hydrostatic test at a pressure which produces a hoop stress of at least 85% of the specified minimum yield strength, and(e) the holder, connection pipe, and any component shall be leak tested after installation in compliance with the Ninth Schedule.Transmission line valves3.64 A transmission line other than an offshore segment, shall have sectionalising block valves spaced as follows:(a) each point on the pipeline in a Class 4 location shall be within 4 kilometres of a valve,(b) each point on the pipeline in a Class 3 location shall be within 6 kilometres of a valve,(c) each point on the pipeline in a Class 2 location shall be within 12 kilometres of a valve, and(d) each point on the pipeline in a Class 1 location shall be within 16 kilometres of a valveunless the Commission in a particular case determines that alternative spacing may provide an equivalent level of safety.3.65 A person who fixes a sectionalising block valve on a transmission line, other than an offshore segment, shall ensure that(a) the valve and the operating device to open or close the valve is readily accessible and protected from tampering and damage, and(b) the valve is supported to prevent settling of the valve or movement of the pipe to which it is attached.3.66 Without limiting paragraph 3.65(a) a section of the transmission line other than an offshore segment between the main line valves shall have a blow-down valve with sufficient capacity to enable the transmission line to be blown down as rapidly as practicable,(b) each blow down discharge shall be located in a manner that will permit the(i) blowing of gas into the atmosphere without hazard, and(ii) gas to be directed away from an electrical conductor if the transmission line is adjacent to an overhead electrical line.3.67 An offshore transmission line shall be equipped with valves or any other component to shut off the flow of gas to an offshore platform on an emergency.Distribution line valves3.68 A high-pressure distribution system shall have valves spaced in a manner that can reduce the time to shut down a section of the mains in an emergency.3.69 Valve spacing shall be determined by the operating pressure, the size of the mains and local physical conditions.3.70 A regulating station that controls the flow or pressure of gas in a distribution system shall have a valve installed on the inlet piping at a distance from the regulating station to permit the operation of the valve during an emergency.3.71 Where a person installs a valve on the mainline for the purpose of operation during an emergency, that person shall ensure that(a) the valve is placed in a readily accessible location so as to facilitate its operation in an emergency,(b) the operating mechanism is readily accessible, and(c) the box or enclosure is installed so as to avoid transmitting any external load to the mainline if the valve is installed in a buried box or enclosure.Structural design requirements of vaults3.72 A person who designs an underground vault or pit for a valve, a pressure relieving, pressure limiting, or pressure regulating station, shall ensure that(a) it has the capacity to meet the loads imposed on it,(b) the installed equipment is protected, and(c) there is enough working space so that all of the equipment required in the vault or pit can be properly installed, operated and maintained.3.73 An operator shall ensure that each pipe that enters a regulator vault or pit is made of steel and is of a size equivalent to 254 millimetres or less, except that a control or gauge piping may be made of copper.3.74 Where a pipe extends through the vault or pit structure, provision shall be made to prevent the passage of gas or liquid through the opening and to avert any strain in the pipe.Accessibility of vaults3.75 A vault shall be located in an accessible location and, as far as practicable, away from(a) a street intersection or point where traffic is heavy or dense,(b) any point of minimum elevation, catch basin, or place where the access cover will be in the course of surface waters, and(c) water, electricity, steam or other facilities.Sealing, venting and ventilation of vaults3.76 An underground vault or closed top pit containing a pressure regulating station, a pressure reducing station, or a pressure limiting or relieving station, must be sealed, vented or ventilated as follows(a) when the internal volume exceeds 5.66 cubic metres(i) the vault or pit shall be ventilated with two ducts, each with at least the ventilating effect of a pipe 102 millimetres in diameter;(ii) the ventilation shall be enough to minimise the formation of combustible atmosphere in the vault or pit,(iii) the ducts shall be high enough and above grade to disperse any gas-air mixture which might be discharged, and(b) when the internal volume is more than 2.12 cubic metres but less than 5.66 cubic metres(i) the opening of a vault or pit that is sealed, shall have a tight fitting cover without open holes through which an explosive mixture may be ignited with a means for testing the internal atmosphere before removing the cover,(ii) if a vault or pit is vented, there must be a means to prevent any external source of ignition from reaching the vault atmosphere, or(iii) paragraph (a) or (c) shall apply, if the vault or pit is ventilated, and(c) no additional ventilation is required if a vault or pit to which paragraphs (a) and (b) apply, is ventilated by(i) any opening in the cover or grating, or(ii) the ratio of the internal volume in cubic metres to the effective ventilating area of the cover or grating in square metres is less than 20:1.Drainage and waterproofing of vaults3.77 A person shall design a vault to minimise the entry of water.3.78 A person shall not connect a vault that contains gas piping to an underground structure.3.79 A person that uses electrical equipment in a vault shall ensure that it meets the requirements in respect of wiring specified in the Electrical Wiring Regulations, 2012 (L.I. 2008).Design pressure of plastic fittings3.80 A thermosetting fitting for plastic pipe shall conform to the standards specified in Part A of the Fifteenth Schedule.Valve installation in plastic pipe3.81 A person who intends to install a valve in a plastic pipe, shall ensure that the design is amenable to the protection of the plastic material of the pipe against any excessive torsional or shearing load when the valve or shutoff is operated and is protected from any other secondary stress which is likely to be exerted through the valve or its enclosure.Protection against accidental over pressuringGeneral requirements3.82 Subject to paragraphs 3.84 and 3.86, each pipeline which is connected to a gas source shall have a pressure relieving or pressure limiting device which meets the requirements of paragraph 3.88 to 3.91 to enable the maximum allowable operating pressure exceed its normal level in case of pressure control failure or any other type of failure.Additional requirements for distribution systems3.83 A distribution system, which is supplied from a source of gas, which is at a higher pressure than the maximum allowable operating pressure, shall(a) have a pressure regulation device that is capable of meeting the pressure, load and other service condition which would be experienced in the normal operation of the system, and that could be activated in the event of failure of some portion of the system, and(b) be designed so as to prevent accidental over pressuring.Control of the pressure of gas delivered from high-pressure distribution systems3.84 A pressure limiting device is not required if the maximum actual operating pressure of the distribution system is 414 kPa gauge, or less and has a service regulator with the following characteristics:(a) a regulator capable of reducing the distribution line pressure to a pressure recommended for a household appliance,(b) a single port valve with proper orifice for the maximum gas pressure at the regulator inlet,(c) a valve seat made of resilient material designed to withstand abrasion of the gas impurities in the gas, cutting by the valve, and to resist permanent deformation when it is pressed against the valve port,(d) a pipe connection to the regulator not exceeding 51 millimetres in diameter,(e) a regulator which under normal operating conditions, is able to regulate the downstream pressure within the necessary limit of accuracy and to limit the build-up of pressure under a no-flow condition to prevent a pressure that would cause the unsafe operation of any connected and properly adjusted gas utilisation equipment, and(f) a self-contained service regulator with no external static or control line.3.85 If the maximum actual operating pressure of the distribution system is 414 kPa gauge, or less, and a service regulator that does not have each characteristic listed in paragraph 3.81 is used, or if the gas contains any material which can seriously interfere with the operation of a service regulator, the distribution system shall have suitable protective devices to prevent unsafe pressuring of a customer's appliances if the service regulator fails.3.86 If the maximum actual operating pressure of the distribution system exceeds 414 kPa gauge, one of the following methods shall be used to regulate and limit, to the maximum safe value, the pressure of gas delivered to the customer:(a) a service regulator that has the characteristics listed in paragraph 3.84 and another regulator located upstream from the service regulator, if(i) the upstream regulator shall not be set to maintain a pressure higher than 414 kPa gauge,(ii) the device is installed between the upstream regulator and the service regulator to limit the pressure on the inlet of the service regulator to 414 kPa gauge or less in case the upstream regulator fails to function properly,(iii) the device installed is either a relief valve or an automatic shutoff which shuts, if the pressure on the inlet of the service regulator exceeds the set pressure of 414 kPa gauge or less, and remains closed until manually reset,(b) a service regulator and a monitoring regulator set to limit, to a maximum safe value, the pressure of the gas delivered to the customer(c) a service regulator with a relief valve vented to the outside atmosphere, with the relief valve set to open to prevent the pressure of gas going to the customer from exceeding a maximum safe value where(i) the relief valve is not built into the service regulator or is installed as a separate unit downstream from the service regulator;(ii) this combination may be used alone only where the inlet pressure on the service regulator does not exceed the manufacturer's safe working pressure rating of the service regulator, or shall not be used where the inlet pressure on the service regulator exceeds 682 kPa gauge;(iii) the methods in sub-