SE543073C2

SE543073C2 - Venting arrangement for a vehicle with liquefied natural gas tanks

Info

Publication number: SE543073C2
Application number: SE1851343A
Authority: SE
Inventors: Marcus Gralde
Original assignee: Scania Cv Ab
Priority date: 2018-10-29
Filing date: 2018-10-29
Publication date: 2020-09-29
Also published as: WO2020091652A1; BR112021006776A2; SE1851343A1; DE112019004631T5

Abstract

The present invention relates to a venting arrangement (20) for a vehicle (1) comprising a liquid natural gas operated fuel system. The vehicle comprising a pair of cryogenic tanks (10, 10') for storing the liquefied natural gas and mounted to a chassis (4) of the vehicle. The venting arrangement comprises a venting pipeline (16) connected to the respective tankand comprising a venting connector (15) comprising a check valve (25) arranged to discharge vapour from the cryogenic tanks (10, 10'). Each of the tanks is connected to the venting connector (15) via the venting pipeline which also comprises a pair of manual valves (14, 14') connected to the respective tank and located between the respective tank and the venting connector, and a pair of check valve devices (17, 17'). Each of the check valve devices is arranged between the respective manual valve (14, 14') and the venting connector (15) and is arranged to allow flow of vapour phase out of the tank at a first pre-determined pressure and to allow flow of vapour phase into the tank at a second pre-determined pressure, wherein the first predetermined pressure is smaller than the second predetermined pressure.

Description

1 Venting arrangement for a vehicle with liquefied natural gas tanks TECHNICAL FIELD The present invention relates to venting arrangement for a vehicle comprising a liquid naturalgas (LNG) operated fuel system and to a vehicle comprising the arrangement as defined in the appended claims.BACKGROUND ART Natural gas, which primarily comprises methane, can be used as fuel in vehicles, e.g. heavyvehicles such as trucks or buses. The vehicle comprises a fuel system, which is configured toutilize the natural gas either as compressed (CNG) or liquefied natural gas (LNG). Liquefiednatural gas is stored at a low temperature, approximately -120 °C, inside a cryogenic tank,which is mounted to the chassis of a vehicle. The tank contains both a liquid and vapour phase of liquefied natural gas and a pressure of 10-16 bar is provided inside the tank. lnstead of a pump, the pressure ofthe vapour may be the principal method of supplying fuel to the engine.

The cryogenic tank is a highly insulated thermos comprising two vessels, a first inner vesseland a second outer vessel. The inner vessel is surrounded by the outer vessel, and a low-conducting ceramic material is arranged between the vessels to provide insulation, while avacuum is drawn between the vessels. By storing methane as liquefied natural gas in acryogenic vessel, the density of the fuel can be increased. The density ofthe liquefied naturalgas is lower than the density of petroleum-based fuels e.g. diesel. Two tanks containingliquefied natural gas are therefore commonly used in heavy vehicles, one on each side ofthechassis of the vehicle. Thus, the liquefied natural gas fuel is sufficient for a driving distance of approximately 1000 km with two tanks. ln order to protect the tank and retain a set pressure, vapour is discharged from the tanks. Thedischarge of this vapour phase from the storage vessel is called venting. The speed ofthepressure build-up depends on the quality ofthe insulation and the amount ofthe liquefiednatural gas in the tank, e.g. there is a slower build-up if more fuel is present. ln addition, the tanks are subjected to ambient air and the warmer ambient temperature will cause heat 2 transfer to the tank. The effect ofthis heat input is warming of the liquefied natural gas, whichwill result in a vaporization of liquefied natural gas and thereby an increase of the pressureinside the storage vessel. This vaporized liquefied natural gas resulted by warming is referredto as boil-off gas. ln order to avoid an excessive pressure in the storage vessel when thevehicle engine is not running, the cryogenic tank is provided with a venting unit comprising aprimary relief valve and a secondary relief valve. The primary relief valve will open when thepressure in the storage vessel exceeds a lower first threshold value, for instance in the orderof 16 bar, in order to release vapour phase ofthe liquefied natural gas from the storage vesseland thereby lower the pressure therein. The secondary relief valve will open when thepressure in the storage vessel exceeds a higher second threshold value, for instance in theorder of 24 bar, in order to release vapour, e.g. boil-off gas from the storage vessel in a situation when the primary relief valve malfunctions.

To fill the tanks, a fuel hose is connected to one of the tanks and liquid fuel is pushed into thetank. The tanks can be connected with fuel piping to each other. The tank pressure should bepreferably of about 9-10 bar when the fill-up is started. As the tanks fill up the pressureincreases and at 16 bar, the fill-up is stopped. |fthe pressure is higher than 9-10 bar, a ventingconnector can additionally be used to reduce the pressure in the tanks. The filling and ventingconnectors may comprise a check valve, which is actuated when connecting occurs. Thus, forexample in case of venting connector with a check valve, the check valve normally preventingvapour from escaping to the atmosphere can be actuated such that venting of the tanks isallowed via the venting connector. The filling connector may additionally have a check valvedownstream of a connector, which prevents the fuel leaking out from the tank if there is afault with the connector. However, the venting connector may not have an additional checkvalve, as it would then block a flow out of the tank. lnstead, a manual venting valve, whichneeds to be manually opened, is fitted on each tank. lf both manual valves are left open duringnormal operation, then vapour in the tanks will be in direct contact with each other. lf thetanks are separated, i.e. when the manual valves are closed, then the pressure will drop in theempty tank and liquid will instead be drawn from the other tank, which is the intended function of the fuel system. 3The manual valves function as a safety arrangement for the fuel system in which liquefiednatural gas is used as fuel, but there is still a need to improve the safety and user friendliness of venting systems.SUMMARY OF THE INVENTION There are problems associated with the existing venting arrangements and especially themanual valves used in the venting arrangements. For example, when filling up the tanks,manual valves in connection with both tanks have to be opened for ventilation ofthe tanks.After the fill-up is finished, the manual valves need to be closed. Thus, the manual valves needto be actuated both before and after filling, as well as before and after each servicing, which islaborious. Furthermore, there is a need to walk from one side to the other of the vehicle twiceduring each filling, i.e. before and after, which is an extra step and makes it more cumbersometo fill up the tanks compared to a diesel driven vehicle. ln addition, the manual valves may be dirty and hard to reach. |fthe valves are not closed after the fill-up, there will be an open vapour line between thetanks. Thus, there is a risk for pressure drop in the fuel system for example in a situation inwhich vapour should only be drawn from an empty tank. ln case of an open connection, thereis an access also to the other tanks vapour. This means that there is a risk that the whole system pressure is reduced, instead of switching from the empty tank to the other tank.

Additionally, since the valves need to be opened and closed manually, there is a risk that theoperator/technician forgets to close the valves, which increases the risk for operationaldisturbances substantially. |fthe tank is overfilled then liquid may be trapped between themanual valves. |fthe manual valves are then closed, there is a risk that a pipe connecting the tanks may burst.

Furthermore, during service at a workshop, should the technician forget to open one or bothmanual valves to discharge vapour and/or boil-off, the vapour will be released via a normalchannel, i.e. via a vent outlet, which may be positioned behind a cab ofthe vehicle, instead ofvia a ventilation tool which can be connected to a ventilation connector during fill-up orservice. There will thus be a release of mainly methane inside a workshop, which is highly undesirable. 4 The problems above are solved by the present solution as claimed in the appended claims.

The present invention relates to a venting arrangement for a vehicle comprising a liquidnatural gas operated fuel system. The vehicle coniprises a pair of cryogeriic tanks for storingthe iiduefied natural gas and they are rnounted to a chassis ofthe vehicle. The ventingarrangement cornprises a venting pipeline arranged for venting the tanks and connected tothe respective tank, and cornprises a venting connector comprising a check valve arranged todischarge vapour from the cryogenic tanks to the atmosphere. Each of the tanks is connectedto the venting connector via the venting pipeline, the venting pipeline cornprising a pair ofmanual valves connected to the respective tank and located between the respective tank andthe veriting connector. The veriting pipeline further cornprises a pair of check valve devices,each of the check valve devices being arranged between the respective manual valve and theventing connector to allow flow of vapour phase out of the tank at a first pre-rieterrriinedpressure and to allow flow of vapour phase into the tank at a second pre--determinedpressure, vvherein the first predeterrnined pressure is smaller than the second predeterrninedpressure. The first pre-determined pressure rnay be from 0-1 bar, but is limited thereto. Thesecond pre-determined pressure may be for example from 'í-S bar, but is also not limitedthereto. For example, the second pre-determined pressure could be for example 5-9 bar larger than the first pre-cletermined pressure.

By the venting arrangement, a simple and robust venting of the tanks can be obtained whilethe risk for operational disturbances caused by manual valves being in a wrong position areminimized. ln addition, the risk for sudden pressure drops in the tanks is minimized, wherebya more robust fuel supply to the gas engine can be provided. Also, if the tanks are overfilled,pipes will not be over-pressurized. Also, further redundancy for the pressure relief valves can be provided.

The check valve device rnay comprise at least one clieck valve arranged or configured to openat the first or second pre-determined pressure. By the use of at least one check valve, a simpleand robust check valve device can be obtained. The check valve device may comprise two checkvalves vvherein one check valve is arranged to allow 'flow of the vapour phase out of the 'tankand the other check valve to allow flow of the t/apour phase into the tank, respectiveiy. Thus, a simple and robust device can be obtained. The check valves may be passive valves. Therefore, 5there is no need for electrical control, whereby the arrangernent may function aiso in case nopower is on än the vehicle. Alternatively, the check valt/es may be electrically controllable activevaives. The active check yalves may be connected to a control system of the vehicle andconfigured to be controllable hy the controi systern. Thus, a more accurate and fiexibie check vaive tïlevice rnay be obtained.

The manual valves may be configured to be opened/closed by means of a tool configured foropening/closiatg of the valves. Thereby, the risk for leaving the yalves in a wrong posätion can bedecreased. The rnartuai valt/es may be arranged at ah open position during the operation of thevehicle and at a closed position during the service of the ventihg eohnector of the vehicie. ihthis way, there is no need to actuate the vaives during normal operation and fiiiing up of the tanks, and thus the vehting arrangernent Es less latioritszis to use.

The present irwerttioh also relates to a vehicle com prising the venting arra ngement as described above.

Further features and advantages are described below in the detailed description with reference to the appended drawings.BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows schematically a vehicle comprising a venting arrangement of the present disclosure in a side view; Fig. 2 shows schematically a coupling scheme of the venting arrangement of the present disclosure;Fig. 3 shows schematically a manual valve and a tool for opening the valve.DETAILED DESCRIPTION An example of vehicle 1, which in the Fig.1is a heavy truck, comprising a liquid natural gas(LNG) operated fuel system, is schematically illustrated in Fig 1. The vehicle 1 comprises aChassis 4, which in the front is configured to support a driver's cab 5 and in the rear to supporta cargo body (not shown). The vehicle 1 is provided with a gas engine 2 that powers the vehicle's tractive wheels 8 via a gearbox 6 and a propeller shaft 7. The engine 2 is powered by 6liquefied natural gas fuel supplied from a cryogenic tank 10 comprising a storage vessel 11, in which the liquefied natural gas to be used as fuel for the engine is stored.

The vehicle may comprise at least two cryogenic tanks 10, 10' (shown in Fig. 2) one on eachside ofthe chassis 4, to which the tanks 10, 10' are mounted by means of suitable mountingmembers 9, which may be for example metallic straps but are not limited thereto. Thecryogenic tanks 10, 10' are provided with a venting arrangement 20, which is connected to the cryogenic tanks 10, 10' comprising storage vessels 11, 11'.

The storage vessels further comprise a primary relief valve (not shown) and a secondary reliefvalve (not shown). The primary relief valve will open when the pressure in the storage vessel11 exceeds a lower first threshold value, for instance in the order of 16 bar, in order to releaseboil-off gas, which is a vapour phase of the liquefied natural gas and which builds up when thetemperature inside the storage vessel 11 increases, from the storage vessel 11 and therebylower the pressure therein. The secondary relief valve will open when the pressure in thestorage vessel 11 exceeds a higher second threshold value, for instance in the order of 24 bar,in order to release boil-off gas from the storage vessel 11 in a situation when the primaryrelief valve malfunctions. The cryogenic tanks 10, 10' are connected to a vent outlet 13, whichin turn is connected to the primary relief valve, wherein boil-off gas released from the storagevessel11 via the primary relief valve will leave the cryogenic tank 10 through this vent outlet 13, which may be located behind the cab 5 of the vehicle.

The vehicle further comprises a venting arrangement 20 of the present disclosure, in which amanual valve 14, 14' for the respective tank 10, 10' is included. By manual valve is meant avalve, which needs to be actuated manually or by means of a tool, i.e. a valve that is notautomatically or electrically actuated. The manual valves 14, 14' are connected to the tanks10, 10' for example by a valve interface 12. The manual valves need to be opened to ventilatethe tanks during fill-up and/or service. The venting arrangement also comprises a ventingconnector 15 comprising a check valve 25 (see Fig. 2). The venting connector 15 is arranged ina venting pipeline 16 between the manual valves 14, 14' and is used to vent the tanks for example during filling of the tanks.

To fill the tanks 10, 10' a fuel connector (not shown) can be connected to one of the tanks and liquid fuel is pushed into the tank. The tanks are connected with piping to each other, and will 7 therefore be equally filled. The tank pressure may be about 9-10 bar when the fill-up isstarted, and will increase as the tanks fill up and at 16 bar the fill up is stopped. lf the pressureis higher than 9-10 bar, the venting connector 15 can be used to reduce the pressure in thetanks. The venting connector 15 may comprise the check valve 25 (see Fig. 2), which isactuated when connecting with a ventilation tool for venting. The filling connector mayadditionally comprise a second check valve, which prevents the fuel leaking out from the tankif there is a fault with the connector. By connecting the venting tool, venting of the vapour phase,, can be performed via the venting connector in a controlled manner.

Fig. 2 shows the venting arrangement 20 of the present invention in more detail. The ventingarrangement 20 comprises the above-mentioned venting connector 15, which comprises thecheck valve 25, which during normal operation is closed, and therefore adds redundancy fromboil-off gas escaping via the venting connector. lnstead, the boil-off gas may be ventedthrough the vent outlet 13 in case the temperature is increased in the tanks. However, duringe.g. tank fill-up and/or service, the check valve 25 may be actuated by coupling a connector orconnector tool (not shown) having a corresponding check valve which can be actuated, andthereby actuate the check valve 25 such that it opens and allows vapour to be discharged from the tanks 10, 10'.

For venting the tanks during e.g. service, the manual valves 14, 14' connected to each tank 10,10' are opened so that the pressure insider the tanks can be decreased if desired. The manualvalves are normally closed during the operation ofthe vehicle and opened during the service.After the service, if both manual valves 14 are left open during normal operation, there is arisk that the vapour phase in the tanks will be in direct contact with each other. Thereby, thereis a risk for pressure drop in the fuel system, which may cause problems in the fuel supply. lfthe tanks are separated, i.e. when the manual valves are closed, then the pressure will drop inthe empty tank and liquid will instead be drawn from the other tank. This is the intended function of a fuel system without a pump. ln use, liquid is drawn from a liquid pipe 29, 29' inside the respective tank 10, 10', which ispositioned at the bottom while vapour pipe 28, 28' and filling pipes 26, 26' are positioned inthe top of the tank. The tanks will supply liquid fuel to the engine supply 33 downstream of the tanks when the pressure is below 10 bar and vapour if the pressure is above 10 bar. This 8 ensures that the pressure does not drop too much in the tanks, which causes torquelimitations or, if the pressure is allowed to drop below a minimum pressure, ”vehicle of road”(VOR), i.e. an operational stop for the vehicle. Regulating valves 27 and 27' are connected toeach tank 10, 10'. The regulating valve may be for example a dubbed economiser and itcontrols whether liquid or vapour is supplied from the respective tank 10, based on the tankpressure. When liquid is drawn from the tank and it becomes empty, then vapour is drawninstead. The tanks 10, 10' may also comprise a liquid level sensor, and the fuel supply may beadditionally or alternatively based on the liquid level in the respective tank 10, 10'. The liquidlevel sensors may be connected to a control device of the vehicle and the regulating valvesmay be controlled based on the detected liquid level. ln Fig. 2, the tank 10 is nearly empty andthe liquid level 22 is below a level in which the liquid pipe 29 reaches the liquefied natural gas.Thus, vapour is supplied to the engine supply 33 via a supply line 30. lf the pressure dropsbelow a pre-determined pressure value, e.g. 9 bar, which can be measured by a pressuresensor 31 in an engine supply line 33, the automatic shut-off valve downstream of theregulating valve 27 shuts the flow from the tank 10 and instead, fuel will be provided from thetank 10' on the right hand side, which has a higher level of liquid natural gas via a supply line30'. The shut-off valve and the regulating valves may be active valves, i.e. electronicallycontrollable via the control unit of the vehicle. The control unit may control the automaticshut-off valve based on a pressure value measured by a pressure sensor 31. Thus, if thepressure from the tank 10 drops below a pre-determined value of e.g. 9 bar, the controlsystem is configured generate a signal to the shut-off valve and shut the shut-off valve 23, whereby the liquefied natural gas is supplied from the tank 10' instead.

Fuel should principally be drawn equally from each tank, but as the pipe lengths from thetanks are of different lengths and the regulating valves have some tolerances. The practicaleffect is that one tank often is used more than the other tank before it is empty, and the othertank will then subsequently empty. When entering a workshop for service, there is a wish toensure that boil-off gas is not vented into the workshop. To prevent the gas entering theworkshop a venting tool which allows venting to occur at a desired time and location may befitted to the venting connector 15. The manual valves must then be opened for the tool to be able release gas from the tanks 10, 10' via the venting arrangement 20. 9 According to the present invention, the problems associated with the use of manual valves aredecreased by the present venting arrangement 20. Each ofthe tanks 10, 10' is connected tothe common venting connector 15 via a venting pipeiine 16 arranged for venting the tanks 10,1G' and connected to the respective tank. The venting pipeiine 16 exterids between the tanks10, 1G' and connects the tanks 10, 1G' and the storage vesseis 11, 11' thereoi and comprisesthe venting connector 15 between the tanks. The venting connector 15 cornprises the checkvaive 25 arranged to discharge vapotir phase, i.e. the vapoiir phase ofthe liquefied naturalgas, from the cryogenic tanks to the iocation where the fiii~up of the tanks takes piace. Thecheck vaive 25 can he actuated to discharge vanour by connecting a tooi (not shovvn)configured to actuate the check vaive 25 and thus open the check vaive 25. The yentingpipeiine 16 cornprises a pair of the manuai vaives 14, 14' described above, tvhich areconnected to the respective tank 1G, 10' and iocated between the respective tank and theventing connector 15, eg. in the vaive interface 12 (see Fig. 1 and 3). The veritirig pipeiine 16further corriprises a pair of check vaive devices 17, 17', each of the check vaive devices 1T, 17'being arranged between the respective manuai vaive 14, 14' and the veritirig connector 15 toaiiow fiow of vapour phase out of the tank at a first pre-deterrnined pressure and to aiiovvfiow of the vapoiir phase into the tank at a second predeterrniitett pressure, wherein the firstpredetermined pressure is srnaiier than the second predetermined pressure. By the presentventing arrangerneitt, the manual valves do not need to be actuated during the normaloperation of the vehicle including filling up the tanks with fuel, since the manual valves canalways be in an open position. Thus, when filling fuel to the tanks a user will never need toactuate the manual valves, which will make the fuel system more robust. Therefore, the riskfor operational disturbances or stop caused by the manual valves being in the wrong positionis considerably reduced. The manual valves need only be closed, when the venting connector15 needs service and he removed. in that case, aiso the vaives in the vaive devices 17, 17' need to he ciosed.

The first pre-determined pressure can be determined as desired, but crauid he for exampie befrom 0-1. bar, hut is not iirnited thereto. The second ttre-rieterrtiined pressure is Earger than thefirst ttre-rieterrtiined pressure, but may he deterrnined such that the ttressiire riifferencebetween the tanks does not become too iarge, and can he for exarnpie frorn 7-8 har, but is not Eirnited thereto, Thus, the check valve, which opens for flow out of the tank, is set to open at a very low backpressure to easily allow venting. The check valve, which opens for flow into thetank, instead is set higher, for example at about 7-8 bar, which means that the pressuredifferential between the tanks cannot become larger than 7-8 bar. Thus, should one tankbecome empty first, then the differential between the tanks will be smaller and thus no flowwill take place. Should one tank leak and empty, then the other tank will only reduce itspressure to 7-8 bar, but not empty further. Even ifthis happens, then the fuel system will beable to deliver full power. Additionally the check valves add doubled redundancy of thepressure relief valves, as the relief valves of the other tank are used, albeit at an increasedpressure differential of 7-8 bar from the check valve. Should the primary relief valvemalfunction and not open, then redundancy is today lost for that tank. With the addition ofthe check valves described above, at 24 bar when the secondary relief valve should open, thenalso the primary valve of the other tank would be close to open (24-8=16 bar). Additionally, at32 bar, the secondary relief valve of the other tank opens, should both primary relief valves and one secondary relief valve malfunction.

En Fig. 2, an exampie of the check vaive device 17, 17' is shovvn. Each ofthe check valvedevices 17, 17' comprises two check vaives 171, 172 and 171', 172', respectiveiy. The firstcheck vaives 171, 171' are arranged to aiiow fiow of the vapour phase out of the tank and thesecond check vaives 172, 172' are arranged to aiiow fiow of the vapour phase into the tank,respectiveiy. The first check vaives 1.71, 171' are arranged to aiiow fiow of the vapour phaseout of the tank at e first pracieterrnirietå pressure, which rnay be frorn 0-1. bar. The secondcheck vaives 172, 1,72' are arranged to aiiotw fiow of the vapotir phase into the tank at asecond pre--deterntined pressure, which may be from 7-8 bar. Thus, the first predeterminedpressure is sntaiier than the second predetermined pressure, thereby aiiowing venting of thetanks tvhiie the pressure difference between the tanks can be ntaintained at a higher ievei.Each of the check vaives 171, 172; 171', 172' is configured to open at the first and/or secondpre-determined pressure. Each ofthe check vaives 171, 172; 171', 172' rnay cornprise forexampie a spring or it couid be repiaced with other rnecharticai soiutions, such as pressuresensitive rnernbranes, as iong as the vaive opens at the desired pressure. The check vaives ofthis type are passive vaives, which are sirnpie and robust. The check vaives171, 172; 171', 172'may aiternativeiy be eiectricaiiy controiiabie, i,e. actit/e, vaives. The eiectricaiiy controiiabie check vaives rnay be connected to a controi device of the vehicie and the incoming/outgoing 11vapour pressure may be measured by means of a pressure sensor arranged upstream ordovvnstream ofthe check vaive device to measure the pressure upstrearn or downstreant ofthe check vaive device. The double check valves 171, 172; 171', 172' will ensure that overfillingwill not hinder expansion of the fuel as it warms. ln addition, it is ensured that no pipes can become over-pressured, which may cause operational disturbances or stop of the vehicle.

The manual vaives 14, 14' may be arrangeci to be opened/cioseci by means of a tooi 141configureci for opening/ciosing of the vaives as schematicaiiy shovvn in Fig. 3. For exampie, awheel 142 of the manual valves 14, 14' can be constructed so that a mating tool can grip thewheels. Thus, the tool and the manual valves can be constructed so that there is a matingconnection between connecting parts and so that the tool can rotate the wheel ofthe manualvalve. This will reduce the possibility of inadvertently having the manual valves closed. Aspreviously described, the riianuai vaives are arranged at an open position during the operationof the vehicie and at a cioseci position during the service of the venting connector of thevehicie, Only when there is a need to service the venting connector it is necessary to close themanual valves 14, 14' or the valves of the check vaive device 17, 17”. This also means that therisk for discharge of boil-off gases via the vent outlet 13 situated behind the cab into the workshop is reduced, since the manual valves are already open.

The foregoing description of the present invention is provided for illustrative and descriptivepurposes. lt is not intended to be exhaustive or to restrict the invention to the variantsdescribed, but instead the invention is to be limited by the scope ofthe appended claims.Many modifications and Variations will obviously be apparent to one skilled in the art. Theembodiments have been chosen and described in order best to explain the principles of theinvention and its practical applications and hence make it possible for a skilled person tounderstand the invention for various embodiments and with the various modifications appropriate to the intended use.

Claims

1. CLAll\/IS A venting arrangement (20) for a vehicle (ilcomprising a liquid natural gas operatedfuel system, the vehicle comprising a pair oi cryogenic tanlts (10, 10') for storing theliquelied natural gas and nftounted to a chassismlå) of the vehicle, the ventingarrangement corriprising a venting pipeline (16) arranged for venting the tanlts andarraneeci to he connected to the respective tank, the venting pipeline (16)cr.1rnprisinga venting cranriector (15) comprising a checl< valve (25) arranged to discharge vapouri corinector trorn the cryogenic tanka (10, 1G') to the atrnospliere, wherein the veritin iïtš) is arranﬂed to he connected to each of the tanlrs (1,0. HV) via the venting pipelinemimlmtš), the venting pipeline comprising apair of manual valt/es (14, lllf) arranged to he connected to the respective tanl: (10,10') and located between the respective tanl< (10, 10') and the venting connector (15),characterized in that the venting pipeline (16) lurther cornprises a pair of checlt valvedevices (17, 17"), each olthe check valve devices (17, 17) being arranged between therespective rnanual valve (14, 143) and the venting crahriector (15) and being arrangedto allow flow ot vapour phase out of the tank at a first pre-deterrriined pressure andto allow “llow of vapour phase into the tank at a second tire-deterrnined pressure,vvherein the “lirat predeterrnined pressure is smaller than the second precieterrnined ßfGSSUïE. The venting arrangement (20) oi clairn 1, characterized ih that the first pre-- cletermined pressure is ironi 0-1 bar. The veritirig arrangement (20) of ciaini 1 or 2, characterized in that the second pre- deterrriihed pressure is lrorn 7-8 har. The veriting arrangement (20) ol any of clairris 1 to 3, characterized in that the checkvalve device (17, 17') cornprises at least one check valve (171, 172; 1712 172') configurecl to open at the iirst or second pre-»deterrninecl pressure. 10. Tha ventšng arrangerneett (20) of any of tha preceding ciahns, charactarized in thateach ef the check tfaive devšces (17, 17') compršsas tvvo check tfah/es (171, 172; 171',172), wherešn one check yaive (171, 171') Es arrahgeci to aiioyx/ fiow of the yapotarphase aut of the tank and the other check yaive (172, 172) Es arrahged to aiioyv fiaw of the vapour phase šnto the tank, respectšyeiy. The ventihg arrangetnent (20) of any of ciairnsmffyå, characteršzed in that t-the check vaâyes (171, 172; 1.71', 1.72) are passäve yaâves. Tha ventâhg arrahgemeht (20) of any of ciaäms ﬁêf-S, characteršzad in that the check yah/es (171, 172; 171', 172') are eiecträcaiiy controiiahie actšve vaives. The tfentšhg arrahgement (20) of any of the precedšng ciašnfts, characteršzed in that thernarauai vaives (14, 14') are canhgureti to he operteti/citusecí hy means ot a tooå (141) confägured for openšng/'ciesšrtg of the vaives (14, 15)., The yentšng arrangernent (ZO) ef any of the precediftg cšašrns, characteršzed En that thernanuai vaives (111, 114V) ara arranged at an open pasštšon during the aperatäon m” thevehäcie and at a cfosed position during the servšce of tha vehtähg cohnector (15) otthe yahäcie (1). Vehicle (1) comprising the venting arrangement (20) of any one of the preceding claims 1-9.