Section 0 in Petroleum and Natural Gas Regulatory Board (Technical Standards and Specifications including Safety Standards for Liquefied Natural Gas Facilities) Regulations, 2018

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Union of India - Section

Section 0 in Petroleum and Natural Gas Regulatory Board (Technical Standards and Specifications including Safety Standards for Liquefied Natural Gas Facilities) Regulations, 2018

0. Design and Layout of Facilities

1.1Philosophy. - LNG Terminal lay out philosophy must consider location of the facilities at a site of suitable size, topography and configuration with a view to designing the same to minimise the hazards to persons, property and environment due to leaks and spills of LNG and other hazardous fluids at site. Before selecting a site, all site related characteristics which could affect the integrity and security of the facility shall be determined. A site must provide ease of access so that personnel, equipment, materials from offsite locations can reach the site for firefighting or controlling spill associated hazards or for the evacuation of the personnel.

1.2Basic Information

1.2.1. Information on following items should be collected before proceeding with the development of overall plot plan.

i. Terminal capacityii. Process units and capacitiesiii. Process flow diagram indicating flow sequenceiv. Utility requirementsv. Unloading system along with tanker berthing system with capacityvi. LNG storage tanks, sizes and type of storage tanksvii. Other storage tanksviii. LNG transfer and vaporisationix. Tank truck loading/unloadingx. No. of flaresxi. Provision for spill containment and leak controlxii. Inter distances between the equipmentxiii. Operating and maintenance philosophy for grouping of utilitiesxiv. Plant and non-plant buildingsxv. Environmental considerationsxvi. Fire stationxvii. Chemical storagexviii. Ware house and open storage areas.

1.2.2. Information related to each item should include, but not limited to, following:

i. Extreme temperatures and pressures for normal operations as well as emergency conditions.i. Concrete structures subject to cryogenic temperaturesii. Fail safe designiii. Structural requirementiv. Requirement of dyke and vapour barrierv. Shut off valves and relief devices.

1.2.3. Data on terminal and infrastructure facilities should be identified and collected before detailed layout activity is taken up. Due consideration should be given while deciding/finalising terminal layout to the following:

i. Site location mapii. Seismic characteristics and investigation report.iii. Soil characteristicsiv. Prevailing wind speed and direction over a periodv. Meteorological data including corrosive characteristics of the air and frequency of lighteningvi. Area topography contour mapvii. High flood level in the area and worst flood occurrence.viii. Source of water supply and likely entry / exit pointix. Electric supply source and direction of entry pointx. LNG entry point/ Gas exit pointxi. Minimum inter distances between facilities as well as between facilities & boundariesxii. Storm water disposal point and effluent disposal pointxiii. Approach roads to main Terminal areasxiv. Surrounding risksxv. Air routes and the proximity of the Airports.xvi. Environment impact assessment

1.2.4. Emergency communications equipment shall not be adversely affected by the operation of other devices/equipment in close proximity (electromagnetic compatibility). Emergency communications equipment shall not create additional hazards during an emergency situation GA control systems to be protected against fire, blast and credible accident events, by location or otherwise, such that its ability to function is not impaired for the time taken to muster after a major accident event.

1.2.5. Facilities with the potential to generate waste e.g. process waste water, sanitary sewage or storm water should incorporate necessary precautions to avoid, minimize and control adverse impacts to health, safety or the environment.

1.2.6. Plans shall be developed that considers prevention, reduction, reuse, recovery, recycling, removal and disposal of wastes (including hazardous waste) generated during all project phases and modes of operation.

1.2.7. The project to address potential environmental impacts on existing conditions such as surface, groundwater and soils.

1.2.8. Plans shall be developed to minimize or reduce emissions as far as reasonably practicable, resulting from commissioning, testing activities and operation.

1.2.9. All escape routes including emergency exit doors to be readily accessible, non-slip, marked, signposted and clear of obstructions.

1.2.10. Markings and signs to be clearly visible if there is loss of artificial lighting outside daylight hours.

1.2.11. All escape doors shall be of a type that can easily be opened in an emergency situation.

1.2.12. Rescue breathing apparatus sets and other equipment necessary shall be located at strategic locations around the facilities to allow prompt rescue of personnel.

1.2.13. The communication systems shall be protected by, location of equipment, spatial diversity and equipment redundancy. Internal and external telecommunications in order to perform the emergency function defined by project requirements shall be confirmed between the Control Room, vessel/s and storage / pumping locations and Muster area.

1.2.14. PA / GA cables should be located so that they are protected against accidental loads as far as possible and shall be fire resistant to specifications. PA/GA system shall provide a means of alerting all personnel to the existence of an emergency situation, provide the means to communicate additional information to personnel during an emergency and shall be capable of operating without impairment for the minimum time required to escape to muster locations and then to evacuate to a place of safety after the start of a major accident.

1.2.15. The provision and minimum alarm noise level above local ambient is in accordance with design requirements. In areas with greater ambient noise levels, visual alarms shall also be provided.

1.3Blocks

1.3.1. In addition to points indicated in (NFPA 59A), as applicable, containment of potential spills of LNG or other hazardous liquid, especially in case of LNG storage and jetty area should also be considered.

1.3.2. Layout of Blocks/Facilities. - The LNG may consist of the following basic blocks / facilities:

i. The Jetty for berthing of ship and unloading/loading of LNG.ii. Unloading/loading line from Jetty to shore terminal.iii. LNG Storageiv. Re-gasification consisting of pumping and vaporisation.v. Tank truck loading/unloadingvi. Utility Blockvii. Fire Stationviii. Flare systemix. Control Roomx. Administrative Blockxi. Workshopxii. Warehousexiii. Electrical Substation.xiv. Laboratoryxv. Road loading

1.4Roads. - Access to the moored ships shall be provided. If necessary, a separate road should lead to the berths in order to provide the crew with a free access to the ship.i. All process units and dyked enclosures of storage tanks shall be planned in separate blocks with roads all around for access and safety.ii. Primary traffic roads in the installation should be outside hazardous areas. Roads separating the blocks shall act as firebreaks.iii. Pedestrian pathways should be provided / marked alongside the primary traffic roads.iv. Alternative access shall be provided for each facility so that it can be approached for fire fighting in the event of blockage on one route.v. Road widths, gradient and turning radii at road junctions shall be designed to facilitate movement of the largest fire-fighting vehicle in the event of emergency.vi. Layout of the facilities shall be made to minimize truck traffic ingress in the plant.vii. Two road approaches from the highway / major road should be provided. Both these approaches should be available for receipt of assistance in emergency.viii. Conflict of people movement and vehicle movement shall be avoided.

1.5Location. - i. The receiving terminal should be as close as possible to the unloading jetty.ii. The location shall minimize the level of risk outside the boundary plant taking into account adjacent existing and identified future developments

1.6General Considerations. - The layout shall consider two specific zones i.e. Gas Zone and Non-Gas Zone and identify the applicable blocks within each zone. Minimum inter-distances between blocks / facilities shall be maintained as specified in the regulations or as per the risk analysis studies whichever is higher.

1.7Spacing requirement of LNG Tanks and Process Equipment

1.7.1. LNG Tank Spacing. - i. LNG tanks with capacity more than 265 m3 should be located at minimum distance of 0.7 times the container diameter from the property line but not less than 30 meters. Minimum distance between adjacent LNG tanks should be 1/4 of sum of diameters of each tank. The distance between tanks should be further reviewed in accordance with Hazard assessment, but in no case it shall be less than the criteria mentioned above.

ii. Inter distances between LNG Storage tank shall be as under:Table - 1 Distances from Impoundment Areas to Buildings and Property Lines

Container Water Capacity (m3)	Minimum Distance from Edge of Impoundment orContainer Drainage System to Buildings and Property Lines (m)	Minimum distance between adjacent containers(m)
<0.5	0	0
0.5-1.9	3	1
1.9-7.6	4.6	1.5
7.6-63	7.6	1.5
63-114	15	1.5
114-265	23	¼ of the sum of the diameters of adjacentcontainers but not less than 1.5 m
>265	0.7 times the container diameter but not lessthan 30 m

Table - 2 Distances from underground containers and Exposures

Container Water Capacity (m3)	Minimum Distance from Edge of Impoundment orContainer Drainage System to Buildings and Property Lines (m)	Minimum distance between adjacent containers(m)
< 68.1	4.6	4.6
68.1 -114	7.6	4.6
> 114	12.2	4.6

Note : i. A clear space of at 0.9 m shall be provided for access to all isolation valves serving multiple containers.ii. Any LNG storage / process equipment of capacity more than 0.5 M3 shall not be located in buildings.

1.7.2. Vaporiser Spacing. - Vaporisers and their primary heat sources unless the intermediate heat transfer fluid is non-flammable shall be located at least 15 m from any other source of ignition. In multiple vaporiser installations, an adjacent vaporiser or primary heat source is not considered to be a source of ignition. Integral heated vaporisers shall be located at least 30 m from a property line that may be built upon and at least 15 m from any impounded LNG, flammable liquid, flammable refrigerant or flammable gas storage containers or tanks. Remote heated, ambient and process vaporisers shall be located at least 30 m from a property line that can be built upon. Remote heated and ambient vaporisers may be located within impounding area. The inter distances in multiple heated vaporisers a clearance of at least 2 m shall be maintained.

1.7.3. Process Equipment Spacing. - i. For Process equipment spacing shall be in line with process design requirements keeping in view the operation, maintenance and safety considerations.

ii. Fired equipment and other sources of ignition shall be located at least 15 m from any impounding area or container drainage system.The minimum separation distances between various blocks, process units and other facilities shall be as per Annexure- II.

1.7.4. Unloading Facilities

1.7.4.1General Requirements. - i. The LNG jetty should comply with the requirement as specified in "Site Selection and Design for LNG Ports and Jetties"- Information paper no. 14, February 1997 and also "Liquefied Gas Handling Principles on Ships and in Terminals" published by Society of International Gas Tankers and Terminals Operators (SIGTTO).

ii. General cargo, other than ships' stores for the LNG tanker, shall not be handled over a pier or dock within 30 m of the point of transfer connection while LNG are being transferred through piping systems. Ship bunkering shall not be permitted during LNG unloading operations.iii. Vehicle traffic shall be prohibited on the berth within minimum 30 m of the loading and unloading manifold while transfer operations are in progress. Warning signs or barricades shall be used to indicate that transfer operations are in progress.iv. Prior to transfer, the officer in charge of vessel cargo transfer and the officer in charge of the shore terminal shall inspect their respective facilities to ensure that transfer equipment is in the proper operating condition. Following this inspection, they shall meet and determine the transfer procedure, verify that adequate ship-to-shore communications exist, and review emergency procedures.v. Interlocking between ship and terminal control room to be established and the control of unloading operations shall be monitored from the terminal control room.vi. Terminal Security. An effective security regime should be in place to enforce the designated ignition exclusion zone and prevent unauthorised entry of personnel into the terminal and jetty area, whether by land or by sea.vii. Operating Limits. Operating criteria, expressed in terms of wind speed, wave height and current should be established for each jetty. Such limits should be developed according to ship size, mooring restraint and hard arm limits. Separate sets of limits should be established for:

(a)berthing,

(b)stopping cargo transfer,

(c)hard arm disconnection, and

(d)departure from the berth.

1.7.4.2The ships should be berthed in such way that in case of emergency the ship can sail out head on immediately. All other instructions and procedures of Port Regulatory Authority are to be observed.

i. A jetty shall be earmarked for LNG unloading/loading and if other liquefied gases and petroleum products are also proposed to be handled at the same jetty, risk assessment shall be carried out for consideration in design basis as well as the minimum inter distance requirements between various facilities at jetty. Further, the minimum distance between the jetties shall be finalized based on the risk analysis or recommendations of port authorities whichever is higher.ii. The number and size of the berths should be determined by the quantity of LNG delivered, the size of the ships, time intervals between two ships & site conditions. The berths may be installed either parallel or perpendicular to the bank at the end of the jetty depending on the water depth, prevailing wind speed and the location of the basin.iii. The berth may include either simple dolphins or sophisticated platform which includes the unloading arms. Access to the moored ships shall be provided. If necessary, a separate road may lead to the berths in order to provide the crew with a free access to the ship.iv. Mooring layout. The jetty should provide mooring points of strength and in an array which would permit all LNG carriers using the terminal to be held alongside in all conditions of wind and currents.v. Exclusion of ignition Sources: No uncontrolled ignition source should be within a predetermined safe area, centred on the LNG carrier's cargo manifold. The minimum area from which all ignition sources must be excluded should be determined from the design considerations and dispersion studies envisaged in the risk analysis report.vi. A pier or dock used for pipeline transfer of LNG shall be located so that any marine vessel being loaded or unloaded is at least 30 m from any bridge crossing a navigable waterway. The loading or unloading manifolds shall be at least 60m from such a bridge.vii. LNG and flammable refrigerant loading and unloading connections shall be at least 15 m from uncontrolled sources of ignition, process areas, storage containers, control room and important plant structures. This does not apply to structures or equipment directly associated with the transfer operation.viii. Quick Release Hooks. All mooring points should be equipped with quick release hooks. Multiple hook assemblies should be provided at those points where multiple mooring lines are deployed so that not more than one mooring line is attached to a single hook.

1.8LNG Road Tanker Loading / Unloading Facilities. - i. The layout of the LNG facilities including the arrangement and location of plant roads, walkways, doors and operating equipment shall be designed to permit personnel and equipment to reach any area affected by fire rapidly and effectively. The layout shall permit access from at least two directions.ii. LNG tank lorry loading gantry shall be covered and located in a separate block and shall not be grouped with other facilities.iii. Adequate space for turning of tank Lorries shall be provided which is commensurate with the capacities of the tank trucks. However, the space for turning of tank Lorries with minimum radius of 20 M to be provided.iv. Maximum number of LNG tank lorry bays shall be restricted to 8 in one group. Separation distance between the two groups shall not be less than 30 M.v. The layout of the loading location shall be such that tank truck being loaded shall be in drive out position.vi. The weigh bridge of adequate capacity shall be provided and proper manoeuvrability for vehicles.vii. The consideration to be given for the dedicated parking area for LNG tank trucks with controlled access of other vehicles. The parking area shall be located in a secured area and provided with adequate no. of hydrants / monitors to cover the entire parking area. The suitable arrangement for safe venting of vapor generated during waiting period in the parking area, preferably to a closed system should be considered.viii. Escape routes shall be specified and marked in LNG plants for evacuation of employees in emergency. Properly laid out roads around various facilities shall be provided within the installation area for smooth access of fire tenders etc. in case of emergency.

1.8.1. Confinement. - Confined or partially confined zones shall be avoided as far as possible, in particular:

i. Gas and LNG pipe-work shall not be situated in enclosed culverts when it is possible to avoid this for example where road bridges cross pipe ways;ii. The space situated under the base slab of raised tanks, if any, shall be sufficiently high to allow air to circulate;iii. Where cable culverts are used they shall be filled with compacted sand and covered with flat slabs featuring ventilation holes to minimise the possibility of flammable gases travelling along the culverts through voids above the sand. As the sand settles the slabs will sink. They can be restored to their original elevation by adding sand.

1.8.2. Impounding basin. - The extent of the impounding basins and spillage collection channel for LNG and hydrocarbon pipework and equipment shall be evaluated as a part of the hazard assessment . In general it has been found that the collection of spill from interconnecting LNG and hydrocarbons piping, without branch, flanges or instrument connections, is not justified by hazard assessment. If required, it shall be designed to accommodate potential leaks that will be identified in the hazard assessment. Possible LNG spills should be drained into impounding basins, with foam generators or other measures for improved evaporation control. The location of the impounding basin with respect to adjacent equipment shall have regard to the hazard assessment and heat flux. In addition, means for limiting evaporation and reducing the rate of burning of ignited spills and consequences should be considered.

1.8.3. Control Room and Substation. - i. The minimum distance of 60 m shall be maintained from control room and substation to LNG Storage Tank and process area

ii. In case, control room and/ or substation is within 60 metres from LNG Storage Tank and process area due to operational requirement, it shall be made blast proof and safety measures as recommended in risk assessment study shall be taken.

1.8.4. Buildings and Structures. - Buildings or structural enclosures in which LNG, flammable refrigerant and gases are handled shall be f lightweight, non-combustible construction with non-load-bearing walls.

2.0Storage Tank. - The Liquefied Natural gas is stored at about -159°C to -168 °C. LNG tanks are required to be designed to ensure proper liquid retention, gas tightness, thermal insulation and environment safety.

2.1Selection Criterion. - 2.1.1. The selection of storage tanks shall be decided based on the location, adjacent installations, habitation on the surrounding, operational, environmental, safety and reliability considerations. The main criteria for selection of the type of tank shall be decided based on the risk analysis study and the level of risk it is posing on the surrounding.

2.1.2. The following list summarises a number of loading conditions and considerations that have influence on the selection of the type of storage tank.

i. The factors which are not subjected to control:a) Windb) Snow, Climatec) Objects flying from outside the plant.ii. The factors that are subjected to limited controla) Earth quake - OBE/SSE eventb) In plant flying objectsc) Maintenance Hazardsd) Pressure waves from internal plant explosionse) Fire in bund or at adjacent tank or at plant.f) Overfill, Overpressure ( process), block dischargeg) Roll overh) Major metal failure e.g. brittle failurei) Minor metal failure e.g. leakagej) Metal fatigue, Corrosionk) Failure of pipe work attached to bottom ,shell or roofl) Foundation collapse.iii. The factors that are subjected to full controla) Proximity of other plantb) Proximity of control rooms, offices and other buildings within plantc) Proximity of habitation outside plantd) National or local authority requirementse) Requirements of the applied design codes.

2.1.3There is no limit on the height of the tank envisaged other than engineering and aviation considerations.

2.1.4No capacity restriction for LNG tank is envisaged considering the technological developments in this area.

2.2The tanks shall be designed as per EN14620 or API 620 and API 625.The impounding Area and Drainage System and Capacity shall be in accordance with NFPA 59A.

2.3Maximum allowable working pressure should include a suitable margin above the operating pressure and maximum allowable vacuum.

2.3.1. Material of construction. - The material for various parts of LNG container which will be in contact with LNG or cold vapour shall be physically and chemically compatible with LNG. Any of the materials authorised for service at (-) 168oC by the ASME Boiler and Pressure Vessel Code shall be permitted. Normally, for single containment tank, improved 9% Ni steel / Austenitic stainless steel / Aluminium Magnesium alloy are used. For double, or full containment tanks, 9% Ni steel with impact testing is used. In case of membrane tanks, normally austenitic stainless steel is used as material of construction for membranes.

2.3.2. Liquid loading. - i. The maximum filling volume of LNG container must take into consideration the expansion of the liquid due to reduction in pressure to avoid overfilling.

ii. For double containment and full containment, the primary container shall be designed for a liquid load at the minimum design temperature specified. The design level shall be the maximum liquid level specified or the level 0.5 m below the top of the shell, whichever is lower.iii. The outer tank for Double containment, Full containment and membrane tanks, shall be designed to contain the maximum liquid content of the primary container at the minimum design temperature specified. Outer concrete tank shall have 9% nickel steel secondary bottom and 9% nickel steel insulated `Thermal Corner Protection' (TCP) alternatively, austentic stainless steel can be used for membrane tanks as specified in EN 14620. These are linked together. The top of the TCP is anchored into pre-stressed concrete wall, at least 5 meters above the base slab.

2.3.3. Insulation. - i. The LNG tanks shall be adequately insulated in order to minimise the boil off gas generation due to heat leak from ambient. The extent of insulation depends on boil off considerations for which the storage tank is designed. Proper insulation shall be ensured in tank base, tank shell, tank roof, suspended deck etc.

ii. The possibility of an adjacent tank fire must be taken into consideration when designing insulation for LNG storage tanks. Tank spacing, water deluge systems, quantity and hazard index of LNG contents must be considered when specifying insulating materials

2.3.4. Soil Protection. - i. The soil under the on ground LNG storage tank shall not be allowed to become cold.. To prevent such occurrence heating system shall be provided in the foundation to maintain the tank foundation at its coldest location within acceptable temperature range i.e. +5°C to +10°C with an automatic on/off switch system. As an alternative to electrical bottom heating system free ventilated tank bottom by elevated structure is also used. Also slope shall be ensured for the paved portion below the tank from centre to periphery to avoid accumulation of liquid. Gas detectors shall be provided for detection of any leakage and accumulation below the tank.

ii. Electrical heating system shall consist of a number of independent parallel circuits so designed that electrical failure of any one circuit does not affect power supply to the remaining circuits. Electrical heating shall be so designed that in the case of electrical failure of a main power supply cable or a power transformer, sufficient time is available to repair before damage occurs due to excessive cooling. Alternatively, provision for connecting a standby heating power source should be made.

2.3.5. Leak Detection. - Leak detection facility shall be provided in the space between primary container and secondary container. Liquid may be present in the annular/ insulated space due to spillage from inner tank or leak of the inner tank. Temperature sensors shall be used for leak detection. A system alarm shall be provided if there is a malfunction in the monitoring system.

2.3.6. Pressure and Vacuum relief system. - The following guidelines for the design of pressure and vacuum relief system of cryogenic LNG tanks shall be provided;

i. Pressure relief valve shall be entirely separate from the vacuum relief valve. Pressure relief valve shall relieve from inner tank. In order to take care of mal-function/ maintenance of any of the relief valves due to blockage in the sensor line, one extra relief valve (n+1) shall be installed. Pilot operated pressure relief valves are preferred over pallet operated relief valves. Suitable system/ mechanical interlocks shall be provided to ensure that the requisite no of PRV in line all the time.ii. Vacuum relief valves (n+1 philosophy) shall relieve into the space between the outer roof and suspended roof. Pilot operated vacuum relief valves are not acceptable for vacuum protection as the valve action is not fail safe against main valve diaphragm or bellows rupture. Conventional pallet type vacuum relief valves shall only be used. Suitable system/mechanical interlocks shall be provided to ensure that the requisite no of VRV in line all the time.iii. Relief valves or rupture disc to atmosphere should be adequately sized which shall be capable of discharging flow rates from any likely combination of the following :a) evaporation due to heat input in tank, equipment and recirculation lines;b) displacement due to filling at maximum possible flow-rate or return gas from carrier during loading;c) flash at filling;d) variations in atmospheric pressure;e) vapourised LNG in de-super heaters;f) recirculation from a submerged pump;g) roll-over.to relieve the worst case emergency flows, assuming that all outlets from the tank are closed, including the outlet to flares and also boil off gas. Vapours may safely be disposed to atmosphere, provided that this can be accomplished without creating problems like, formation of flammable mixture at ground level or on elevated structure where personnel are likely to be present and in no case it shall be less than 3 m from nearest platform.iv. Provision shall be made to inject nitrogen or dry chemical powder at the mouth of pressure safety relief valve discharge.v. Vacuum relief should be based on: withdrawal of liquid at the maximum rate, withdrawal of vapour at the maximum compressor suction rate, variation in atmospheric pressure etc.vi. A hot flare shall be provided for system to maintain pressure. The flare stack should be continuously purged in order to avoid air ingress and shall be provided with pilot burner.vii. Provision shall be made to maintain the internal pressure of LNG container within the limits set by the design specification by releasing to flare via a pressure control valve installed in the BOG line from tank to compressor. Factors that shall be considered in sizing of flare system shall include the following:viii. Operational upsets, such as failure of control device / BOG compressor tripping etc.ix. Vapour displacement and flash vaporisation during fillingx. Drop in barometric pressurexi. Reduction in vapour pressure resulting from the introduction of sub cooled LNG into vapour space.xii. For the pressurised systems, the safety relief valve vent shall be so positioned to release the hydrocarbon at safe height.xiii. Relief from tank PSV shall not form a cloud on the tank and the PSV discharge shall be routed to safe height in accordance with dispersion study and risk analysis.

2.3.7. Tank Roll Over

2.3.7.1. Under certain conditions "roll over" of the liquid in the LNG tank can occur resulting in the rapid evolution of a large quantity of vapour with the potential to over pressurise the tank. Stratification can occur in an LNG tank if the density of the liquid cargo charged to the tank is significantly different from the left over LNG in the tank. Inlet piping must be designed to avoid stratification of LNG. This can be done by having top and bottom fill lines to inject denser LNG at the top and lighter LNG at bottom. This can also be done by providing distribution holes along the fill line extending to the bottom. Temperature sensors are put to monitor the temperature of the liquid throughout the liquid height at regular intervals. Provision for density measurement on tank shall be provided for the entire height of the tank.

2.3.7.2. For taking care of over pressurisation due to roll over, one of the following options shall be provided, namely :-

i. Calculation of pressure relief valves or Flare/vent system shall to be designed to account for rollover scenario;ii. Rupture disc if provided on the tank with isolation valve (lock open condition) releasing to atmosphere;a) Means to check rupture disc integrity should be provided. Fragments of the rupture disc should not fall into the tank;b) Failure of the rupture disc shall trip all the boil off gas compressors automatically.

2.3.8. Over-Fill of Inner Tank. - i. Two independent type level measuring instruments shall be provided. The level instrument shall be equipped to provide remote reading and high level alarm signals in the control room. In addition, an independent transmitter for high level alarm and high - high level alarm with cut off shall be provided. The high - high level should be hard wired directly to close the liquid inlet valves to the tank.

ii. The tank shall not be provided with overflow arrangement.

2.3.9. The membrane containment tank systems shall also meet the additional requirements as specified in NFPA 59A.

2.3.10. Dyke. - i. Dyke shall be provided for the following types of LNG storage tanks

a) Single containment tankb) Double containment with metallic outer tankc) Full containment with metallic outer tankd) Membrane tank with metallic outer tankDyke is not required for full containment or membrane containment tanks with pre stressed concrete wall.

2.3.11. Other Considerations. - i. Where cryogenic storage tanks are located near process plants with a likelihood of exploding process equipment, the impact of flying object on the tank, one 4" valve travelling at 160 km/h (object of 50 kg weight with a speed of 45 m/sec) shall be considered.

ii. For the tank located within the flight path of an airport, the impact of a small aircraft or component shall be taken care of.iii. Impact of explosion wave due to major leak from a nearby natural gas pipeline or a major spill of LNG may also be considered.iv. Failure of inner tank: Where a sudden failure of inner tank is considered, the outer tank shall be designed to withstand the consequent impact loading.v. Earthquakes: The risk level is determined on the basis of the seismic classification of the location. The data pertaining to the seismic activity level having been ascertained, the structure is to be designed taking into consideration of IS-1893 and other relevant codes.vi. Rainfall runoff from the tank roof should be directed to a curbing and collecting system around the outer edge of the roof. Collected rainwater shall be carried by a drainage piping system that directs the rainwater away from any LNG spill carrying surfaces and to graded drainage areas that are beyond (outside) the ring road.

2.3.12. Nozzles. - There shall be no penetrations except for anchor straps, of the primary and secondary container base or shell walls for LNG tanks to ensure fluid tightness

In addition to the nozzles used for regular operations like liquid inlet, pump outlet, vapour outlet and instrument connections the following provision shall also be provided.i. Nitrogen connections for:a) inertisation of inner tankb) outer tank and insulating material.ii. Chill down connections for the inner tank.iii. Depressurisation and purging of the in-tank pump column.

2.4Instrumentation and Process Control for Tanks. - The instrumentation shall be suitable for the temperature at which LNG is stored. All instrumentation shall be designed for replacement or repair under tank operating conditions in a hazardous gas zone area. Instrumentation for storage facilities shall be designed in such a way that the system attains fail-safe condition in case of power or instrument air failure.The Level instrumentation for ESD function shall be separate and independent of the device for monitoring.

2.4.1. Level. - i. LNG containers shall be equipped with two independent liquid level gauging devices to monitor tank levels .

ii. Each system shall have High and High High Level alarms.iii. Local Level indication should be available at grade apart from remote indication in the control room.iv. Density variation shall be considered in the selection of gauging devices.

2.4.2. Pressure. - i. The storage tank shall be provided with pressure transmitters to continuously monitor and control pressure with an indication in the control room and indication in field at grade level.

ii. Instrument for detecting High Pressure shall be independent of the tank pressure monitoring instrument.iii. The sequence for over pressure control and protection shall be as follows:a) High pressure alarmsb) Increasing the BOG system to the full load.c) Further increase in pressure shall be controlled by releasing to Flare.d) Further increase in pressure shall be controlled by closing of inlet automated valve.e) The final over pressure protection shall be PSV and tank design pressure.All the above pressure control and actuation shall be on independent pressure transmitters.iv. Independent Pressure transmitters shall be provided for low pressure detection that will trip the boil off gas compressors.v. In the event of continued drop in tank pressure, three layers of protection against vacuum shall be provided.a) The trip of the BOG compressors.b) The trip of the pumps.c) Automatic admission of natural gas from outside source into the tank vapour space.d) In the unlikely event this is not sufficient, a set of vacuum breakers installed will admit air into the space between the suspended deck and outer roof to prevent permanent damage to the tank.vi. The independent pressure transmitters shall be provided for the natural gas admission for vacuum protection.

2.4.3. Temperature. - i. As LNG is a product of varied compositions, it would be necessary to measure temperature of liquid and vapour over the full tank height; the sensors being located at 2 meter intervals or every 10% interval of the tank height, whichever is less.

ii. Measuring and recording the formation of layers of liquid with different temperatures should warn the operator of a possible roll over phenomenon.iii. In addition, for monitoring of the initial chill down operation, temperature elements are required to be provided at tank base and shell of both the primary and secondary containers.iv. These temperature elements must be provided at various heights and at various locations of the base to ensure monitoring and proper chilling of the tanks.

2.4.4. Gas Detectors. - Automatic gas detection system for monitoring leakage of LNG to be installed. Adequate number of gas alarm sensors shall be placed on the tank roof in the vicinity of roof nozzles and locations where the possibility of gas or liquid release exists including below elevated tanks. The facility shall be equipped with Emergency shutdown system. The ESD should be able to operate remotely / locally. Need for any automatic actuation of ESD may be assessed based on risk perceptions.

2.4.5. Leak Detectors. - i. Monitoring leaks through the primary container in double containment systems shall be provided by one of the following means :

a) Temperature measurement sensors in annular/insulated space.b) Gas detectionii. The arrangement shall have redundancy to prevent spurious alarms.iii. Tank external leak / spillage detection shall be installed at every location where leaks are credible. These detectors may activate appropriate process shutdowns or isolation, activate remote operated fire protection systems or initiate emergency actions by Operators.iv. The following leak detection devices shall be considered:a) Low temperature sensors for LNG spills.b) Flammable gas detection of IR type. Battery limit fences shall have open path type detectors.c) Flame detectors of the UV/IR typed) Heat temperature detectors for protection of tank relief valve fires and activation of tail pipe extinguishing packages, if provided.e) Smoke detectors of the ionisation typef) CCTV systems in unmanned areas and unloading Jetty, capable of detecting vapour clouds, fitted with motion sensor alarms.g) Communication system between field operators, Jetty terminal and pipeline dispatching centre.

2.4.6. Density Meters. - i. Density Meters shall be provided on the storage tanks to check the homogeneity of LNG.

ii. The density of LNG in the Tank shall be monitored at all levels and analysis performed to alert the operator of any density layering.

2.4.7. The Linear and Rotational inner tank movement should be considered in the design for the relative movement of the liquid container with respect to outer tank.

2.4.8. A provision in the tank for endoscopic inspection ( through insertion of camera ) should also be considered. This will be helpful to know the health of the tank in the absence of visual inspection of the tank.

2.4.9. An Uninterruptible Power Supply (UPS), with battery back-up shall be provided to all critical instrumentation control and safety (F&G) systems so that plant may be kept safe in case of emergencies.

3.0Regassification Facility

3.1Vaporisers and Connected Piping. - i. Vaporisers shall be designed for working pressure at least equal to the maximum discharge pressure of the LNG pump or pressurized container system supplying them, whichever is greater.ii. Manifold vaporisers shall have both inlet and discharge block valves at each vaporiser.iii. The outlet valve of each vaporiser, piping components and relief valves installed upstream of each vaporiser outlet valve shall be suitable for operation at LNG temperatureiv. Suitable automatic equipment shall be provided to prevent the discharge of either LNG or vaporized gas into a distribution system at a temperature either above or below the design temperature of the send out system. Such automatic equipment shall be independent of all other flow control systems and shall incorporate shut down valves used only for contingency purposes.v. Isolation of an idle manifold vaporiser to prevent leakage of LNG into that vaporiser shall be accomplished with two inlet valves with safe bleed arrangement in between.vi. Each heated vaporiser shall be provided with safety interlock to shut off the heat source from a location at least 15 m distant from the vaporiser. The device shall also be operable at its installed location.vii. A shutoff valve to be installed on the LNG line inlet to a heated vaporiser to be at least 15 m away from the vaporiser. This shutoff valve shall be operable either at installed location or from a remote location and the valve shall be protected from becoming inoperable due to external icing conditions.viii. If a flammable intermediate fluid is used with a remote heated vaporiser, shutoff valves shall be provided on both the hot and cold lines of the intermediate fluid system. The controls for these valves shall be located at least 15 m from the vaporiser.ix. The vaporisers shall be fitted with local as well as control room indications for pressure and temperature of both fluid streams at inlet and outlet.x. Instrumentation for storage, pumping and vaporization facilities shall be designed for failsafe condition in case of power or instrument air failure.

3.2Relief Devices on Vaporisers. - i. Each vaporiser shall be provided with safety relief valves sized in accordance with the following as applicable :a) The relief valve capacity of heated or process vaporisers shall be such that the relief valves will discharge 110 percent of rated vaporiser natural gas flow capacity without allowing the pressure to rise more than 10 percent above the vaporiser maximum allowable working pressure.b) The relief valve capacity of ambient vaporisers shall be such that the relief valves will discharge at least 150 percent of rated vaporiser natural gas flow capacity without allowing the pressure to rise more than 10 percent above the vaporiser maximum allowable working pressure.ii. Relief valves on heated vaporisers shall be so located that they are not subjected to temperature exceeding 60 °C during normal operation unless designed to withstand higher temperature.iii. The discharges from the relief valves shall be located at a safe height from adjoining operating platform.iv. The safety relief valves may discharge directly to the atmosphere to a safe location. If this is not possible, the discharge of the safety relief valves shall be routed to the flare or to the vent.

4.0Loading / Unloading Arm and Marine Facilities

4.1Loading / Unloading Arms. - i. Unloading arm consist of pipe length connected to each other by swivel joints, moved by hydraulic actuators. The connection of the arm end to the ship crossovers flange shall be provided with a special automatic ERC (Emergency Release Coupler) device. During emergency this automatic device will come into operation and de-coupling system gets activated.ii. Each unloading arm shall be fitted with an Emergency Release System (ERS) able to be interlinked to the ship's ESD system. This system must operate in two stages; the first stage stops LNG pumping and closes block valves in the pipelines; the second stage entails automatic activation of the dry-break coupling at the ERC together with its quick-acting flanking valves. The ERS System should conform to an accepted industry standard.iii. Provision should be given to collect the LNG from the unloading arm to a closed system by way of providing blow down vessel or any other suitable arrangement. No drain shall be open to atmosphere.iv. The size of the arms depends on the unloading flow rate.

4.1.1Flexible Hoses. - i. Flexible hoses may be used to make small temporary connections for the transfer of LNG and other cryogenic liquids such as refrigerant and liquid nitrogen, for example when emptying or filling road tankers of LNG or liquid nitrogen and they can also be used for transfer operations between small LNG carriers and LNG satellite plants. The use of flexible hoses shall be in accordance with the hazard assessment as per EN-1473.

ii. Flexible hoses shall not exceed 15 m in length and 0.5 m³ in volume. Their design pressure shall be limited to PN 40.iii. Flexible hoses shall not be used for the routine transfer of LNG between large LNG carriers and shore at conventional LNG terminals.iv. Flexible hoses shall be designed in accordance with relevant codes and/or standards, such as EN 12434.

4.2Loading/ Unloading Line. - i. The unloading and transfer lines for LNG should have minimum number of flange joints (expansion bellow system should be avoided, expansion loop shall be provided). Consideration should be given to provide cold sensors for flanges of size 200 mm and above as well as where there are clusters of flanges.ii. Length of the unloading line should be kept minimum. In case it is not feasible, alternative options available are:a) To have additional line running parallelb) To have booster pumpc) Increase size of lineiii. The unloading line should be kept in cold condition to avoid stress and cyclic fatigue due to frequent warm-up and cooling down operation.iv. In case of unloading line is used for loading also adequate safety measures to be provided in engineering and design and risk assessment should be done in addition to the requirements as specified in clause 6.0 - Piping.a) Quantative risk analysis (QRA)b) Hazarad and Operability study (HAZOP)c) Standard Operating Procedures (SOP)d) Surge analysise) Interlock logics

5.0Flare. - The following major process components and function shall comprise pressure relief and blow down system.i. Emergency/operational flare system for LNG regasification system (vapour)ii. Flare equipment including stack, tip and flame front generator.iii. Flare System with flare stackThe following shall be the criteria for designing various equipment under these systems.

5.1Flare Header

5.1.1. Following systems are connected to flare header:

i. Blow-down from LNG vaporisersii. Relief from LNG recondenseriii. Relief from BOG compressorsiv. Relief from Fuel Gas Systemv. Blow-down from LNG Tanks vapor systemvi. Blow-down from Natural gas send out header.

5.1.2. However the relief from the following system shall be given to atmosphere to avoid increase of flare load:

i. LNG vaporisers (SCV, Shell & Tube)ii. LNG Storage Tanksiii. Natural gas send out header

5.2Emergency Depressuring

5.2.1A depressurising system shall be provided to reduce the internal pressure, reduce the effect of leakage and avoid the risk of failure of LNG, hydrocarbon refrigerant or gas filled pressure vessels and piping from external radiation.

5.2.2Devices for depressurising high pressure equipment shall allow the pressure of one or more item of equipment to be reduced quickly. These gases shall be sent to the flare system which shall be capable of handling the low temperatures generated during depressurising.

6.0Piping

6.1All Nozzles for the Piping requirements for an LNG tank shall be from the top. Side penetration shall be avoided to minimise risk of serious leakage. The piping requirements includes the following but not limited to:i. Fill linesii. Withdrawal line (Intank pump column)iii. Boil-off line to remove LNG vapour.iv. Cool down line for initial cooling of tanks during commissioning of the tank.v. Nitrogen purge lines to purge the inner tank and annular space.vi. Nitrogen purging line for pump column and foot valve sealing.vii. Instrument nozzles.viii. Pressure make-up line.ix. Pump re-circulation line.x. Purge release vent line.xi. Pressure relief valve linexii. Vacuum relief line

6.2LNG lines are normally fully filled lines. However, during specific operating conditions could result in differential temperatures at the top and bottom of the pipe causing bowing of pipes and potential spills. Piping design should include stress analysis, expansion loops, and supports as well as proper piping and equipment cool down procedures should address differential contraction covering all anticipated operation and upset conditions.

6.3Physical phenomenon such as surge pressure in LNG receipt and transfer lines, flashing and two phase flow shall be addressed in the piping and equipment design. ESD valves shall be fail-safe and fire safe.

6.4Piping loads and thermal expansion / contraction of piping should not be transferred to the Tank nozzle connections. Bellows expansion joints should be avoided in LNG lines.

6.5Valves shall be designed and manufactured for Cryogenic service. Extended bonnet valves are used in cryogenic service with stems in the vertical position.

6.6LNG heats up and expands, if confined to a fixed volume. Hence any potentially blocked piping or equipment should be provided with thermal expansion relief valves with discharge to closed system.

6.7Inlet piping shall be designed to minimize stratification/ layering of LNG [Stratification occurs when heavier LNG has been added at the bottom of a tank with partially filled lighter LNG or lighter LNG added at the top of the heavier LNG or due to ageing (storing for long duration ) of LNG. This leads to sudden and rapid release of vapour, called Roll-over].i. This can be prevented by having two fill lines one ending at the top of the tank and other extending to the bottom, to inject denser LNG at the top and lighter LNG at the bottom. Mixing nozzles may also be used to avoid stratification.ii. Rollover conditions shall be prevented by active management of stored LNG which includes monitoring temperatures and densities, mixing the tank contents by appropriate top and bottom filling or by circulation.

6.8Vaporiser piping involves high flow rates, pressures as well as transition from cryogenic piping materials to carbon steel material. This could result in embrittlement failure if cold gas or liquid were to come in contact with carbon steel , in case of failure of process interlocks.

6.9The effect of low temperature fluid spills on adjacent plant, equipment and structural steel shall be assessed and measures taken to prevent incident escalation and/or endangerment of emergency response personnel, through suitable selection of materials of construction or by embrittlement protection.Such protection shall be achieved by an appropriate material selection (concrete, stainless steel etc.) or by a insulating with material that will protect the equipment and structural supports from cold shock. Insulation shall be designed and installed in accordance with appropriate standards and provision taken to protect outer surfaces from wear and tear.

6.10Equipment and structural support elements should be protected in such a way that their function and form are not adversely affected during the plant operation.

7.0Design of LNG Truck Loading Facility

7.1Description

7.1.1. The purpose of LNG road loading system is to transfer LNG from the storage tanks to tank truck to deliver LNG to other sites via road transportation. The LNG road loading shall be manually operated system, where all activities shall be done in presence of trained personnel. LNG for loading into the tank trucks shall be tapped off from the LNG In-tank Pump discharge. LNG vapour return from the tanker shall be routed to the BOG suction header. When no loading will be in progress the recirculation will be maintained in the LNG filling line, through a recirculation line for maintaining chilled condition. The loading facility to be provided with the LNG liquid loading arm and vapour return arm. For monitoring of uniform chilling of the LNG feed line during no-loading situation, suitable number of skin temperature indications with alarm shall be provided in the control room.

7.1.2. The LNG road tanker shall be double walled vacuum insulated cryogenic vessels suitable for transport at cryogenic conditions. The tank truck for road movement shall be designed, constructed and tested in accordance with the Static and Mobile Pressure Vessels (Unfired) Rules, 2016 as amended from time to time.

7.1.3. Truck Loading facility should consist of the following:

i. LNG filling line, Vapor return line & a recirculation line with adequate instrumentationii. Liquid/Vapour Loading arm, Batch Flow meter & Control Valveiii. Weigh Bridge/ Flow meter for Custody transferiv. Sick Tanker unloading facility

7.2Design Considerations of LNG Loading / Unloading Facilities

7.2.1Loading Facility

Each loading station shall consist of the following:i. Automatic flow control valve or suitable control mechanism meeting similar functional requirements & non return valve shall be provided in LNG loading lines.ii. A vapour return line with an isolation valve connected back to the storage vessel/ BOG line with NRV.iii. The proper tanker earthing connection shall be provided.iv. Properly designed loading arm shall be provided at the end of filling and vapour return lines for connecting to the tank truck. The loading arm end connection type shall be CGA LNG 300 or flanged type. The loading arms shall be provided with breakaway couplings. These arms shall be of approved type and tested as per OEM recommendations.v. Weigh bridges of suitable capacity for tanker weighment shall be provided.

7.2.2Tanker Unloading Facility. - i. The tanker unloading shall be done by any of the following methods:

a) Utilising vapours from BOG compressors discharge.b) Utilizing the gas from the pressurized gas (send out) network with proper pressure control.c) Utilizing tanker pressure building coil.d) Dedicated unloading compressors/pumps.ii. A suitable protection shall be considered for tanker / system over-pressurization and due considerations of impact of high temperature.iii. All drains, vents and safety valve discharges shall be routed to the closed system/flare system. In case of non-availability of flare system, the discharge from safety valve shall be vented to atmosphere at a safe location minimum at an elevation of 3 meter above the nearest working platform for effective dispersion of hydrocarbons. The dedicated drain and vent connections to be provided for the loading and vapour arms. Operational requirement is that after every loading operation, before disconnection, the liquid holdup in the LNG liquid and vapor arms are required to be drained, depressurized and purged. The provision of Drain Pipe can be considered. The liquids collected in the Drain Pipe would gradually vaporize. Nitrogen connection can be provided to facilitate the vaporization process.

7.3Other Considerations

7.3.1Safety System. - i. The gantry shall have gas and spill detector at potential spillage and gas emission locations. There shall be flame detectors which shall cover the entire gantry and detect any fire. In addition, there shall be manual call points at appropriate locations.

ii. The fire and gas detection shall be considered as follows:a) Fire detectorsb) Gas detectorsc) Low temperature (spill) detectori. The signals generated from the detectors shall be integrated with the ESD system.ii. The shutdown valves to be provided for all the process incoming and outgoing lines to/from loading gantry and shall be located at least 15 meters away from the loading gantry at an easily accessible location.iii. The Emergency Shutdown (ESD) philosophy shall be designed to initiate appropriate shutdown action on detection of any emergency situation or through detector signal.iv. Emergency push button or hand switch shall be provided in Control room and also in field at safe location for manual actuation of ESD system and fire water spray system by operator in case of emergency. The field related button/switch to be provided on either end of the gantry at easily accessible locations.v. ESD shall be caused in case of either of the following:a) Signals from two detectors of different types of gas or spill or flameb) Initiation of manual call pointsc) Hand switches provided in the field as well as in the Operator Console & Control Room.In addition, the following logic shall also be performed to stop individual tanker filling operationa) Gas detection will stop filling operation.b) Earth relay contact indicating inadequate earthing of the truck will stop filling operation.In addition to above, fire water spray with deluge system shall also provided in the gantry which is activated either automatically (either Flame/Fire detector or Quartzoid bulb assembly) or manually by manual switches.

7.3.2Safety Precautions. - Following precaution should be taken due to associated hazards during transfer of LNG to or from a tank truck.

i. No source of ignition must be allowed in the area where product transfer operations are carried out.ii. Fire extinguishers suitable for combating LNG fires shall be placed near the tank trucks during transfer operations.iii. The first operation after positioning the truck should be to provide proper earthing connection of the tanker. Earthing shall be disconnected just before the release of the truck.iv. While disconnecting arm, connections shall be loosened only slightly at first to allow release of trapped pressure, if any.v. Always use personal protective equipment (Cryogenic suits, flame retardant overalls etc) while making or breaking the connections to avoid cold burns.vi. The master switch shall be put off immediately after parking the truck in position. No electrical switch on the truck shall be turned "on" or "off" during the transfer operation.vii. No repairs shall be made on the truck while it is in the loading area.viii. Availability of wheel chokes.ix. Filling/transfer operations shall be stopped immediately in the event of -a) Uncontrolled leakage occurringb) A fire occurring in the vicinityc) Lightning and thunder stormProvision to stop the Filling/transfer operations shall be available from field as well as remote location. Stop switch in field shall be located at a safe distance (minimum 15 meters away) from the source of hazard to be protected.

7.4Drain and Vents. - Drain and vents shall be provided to meet all the requirement of draining, purging, venting etc. Appropriate system shall be provided to handle the discharge from the TSV's also.

7.5Requirements for LNG Installations using ASME Containers for stationary applications. - The requirements for installation, design, fabrication, and siting of LNG installations using containers of 379 m3 capacity and less constructed in accordance with the ASME Boiler and Pressure Vessel Code or Gas Cylinder Rules for vehicle fueling and commercial and industrial applications shall be as specified in Annexure- I.

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Union of India - Section

Section 0 in Petroleum and Natural Gas Regulatory Board (Technical Standards and Specifications including Safety Standards for Liquefied Natural Gas Facilities) Regulations, 2018

0. Design and Layout of Facilities