sandalwood Posted May 2, 2019 Share Posted May 2, 2019 Petrol attendant filling up with LPG got enormous flashback. ! He said we had gas leak? Fridge turned to 12 volt. He said he would not put in any more. Gas indicator reads 5 notches ( FULL ). Any ideas, looks like fuse blown somewhere? Does small amount of gas leak during filling. What now? Link to comment Share on other sites More sharing options...
thebishbus Posted May 2, 2019 Share Posted May 2, 2019 Gas should not leak when filling, but will leak as the filling nozzle is disconnected. Brian B. ps. If the 80% cut off valve had stuck open , you may have a gas release from the cylinder safety valve. Link to comment Share on other sites More sharing options...
sandalwood Posted May 2, 2019 Author Share Posted May 2, 2019 Hi Brian. Tks for reply, if filling nozzle disconnected and gas leaks, would that have caused flame to spurt out, my fridge is now nit working and outside vent partially melted. New to this and worried Regards Link to comment Share on other sites More sharing options...
thebishbus Posted May 2, 2019 Share Posted May 2, 2019 Only if there was something to ignite the gas. Brian B. ps How close is the fridge to the gas filling point ? Are you sure it was on 12 volt not gas ? If on 12 volts I suppose a lose sparking connection could ignite the gas. Link to comment Share on other sites More sharing options...
Robinhood Posted May 2, 2019 Share Posted May 2, 2019 ...was the flashback from the 'fridge? Did you close the cylinder valves before filling? Link to comment Share on other sites More sharing options...
bounty hunter Posted May 2, 2019 Share Posted May 2, 2019 Was your fridge lit at time of filling? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 2, 2019 Share Posted May 2, 2019 Sandalwood’s vehicle is a 2012 IH Motorhomes “Tio” and (I think) has an underslung LPG tank. Although in the original posting it was said that the motorhome’s fridge was “turned to 12 volt” during the refilling process, as the fridge is no longer operational and its external ventilation grille is part-melted, the fridge must be the prime suspect for causing the flashback. It’s advised with a user-refillable LPG bottle (eg. a Gaslow canister) that the bottle’s outlet-valve always be closed before the bottle is refilled to protect the regulator that’s ‘downstream’ of the bottle, but that preventative action is often impractical with a LPG tank. Whatever the cause of the flashback, Sandalwood’s motorhome’s gas system (and fridge) now needs immediate professional attention. Link to comment Share on other sites More sharing options...
Robbo Posted May 2, 2019 Share Posted May 2, 2019 If the OP's fridge was turned to AUTO, then it's possible the fridge may have fired up during the filling process. Usually there is a 15 minute delay between switching off the ignition and the ignition of the fridge....to allow safe refuelling at a petrol station. If the onboard gas tank was overfilled more than the 80% cut-off, it's likely liquid LPG would emit from the gas hob. If gas vapour discharges from the gas hob, then it should be safe to use. As Derek suggests, an urgent visit to a MH gas installer is highly recommended to check for leaks and assess damage to the fridge. Link to comment Share on other sites More sharing options...
dicksob Posted May 2, 2019 Share Posted May 2, 2019 Hi, on my previous 2013 Ih, the filling point for the autogas was mounted between the 2 fridge vents and the pipe work went down behind the fridge then under the van to the tank. Is yours the same? If so are you certain fridge wasn’t on gas at the time? Perhaps you could post a picture to show the damage? Bill Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 2, 2019 Share Posted May 2, 2019 The attached photo was taken from an advert for a 2011 IH Tio RL motorhome. Positioning the LPG filling-point there invites trouble as, if the fridge is left running on gas, the likelihood of an accident happening when the LPG tank is being refilled is high. Even if the motorhome has a ‘smart’ fridge that SHOULD not switch itself to gas operation until 10-15 minutes have elapsed after the vehicle has ceased being driven, there’s still the possibility that this ‘safety period’ may not be long enough. Generally, a 3-way fridge will not cool from 12V when a motorhome’s engine is not running and I’m doubtful that, after a motorhome has stopped and its motor turned off, that a fridge’s 12V heater would be able to ignite LPG. So (as has been discussed above) the logical explanation for the flashback is that the LPG was ignited by the fridge’s gas-burner. Whether the LPG that ignited was coming from a leak in the Tio’s gas-system or from the LPG gas-nozzle connection is anybody’s guess. Link to comment Share on other sites More sharing options...
david lloyd Posted May 2, 2019 Share Posted May 2, 2019 sandalwood - 2019-05-02 6:03 AM Petrol attendant filling up with LPG got enormous flashback. ! He said we had gas leak? Fridge turned to 12 volt. He said he would not put in any more. Gas indicator reads 5 notches ( FULL ). Any ideas, looks like fuse blown somewhere? Does small amount of gas leak during filling. What now? I would have thought that an lpg leak would have ignited before the fill was completed (assuming the source of ignition was the fridge firing up) and that the flashback was more likely to be the residual vapour from the inlet when the nozzle is released. On my previous IH PVC I had the small 20ltr tank replaced with a 30ltr tank by Autogas2000 - they were astonished at the location of the filler point between the two fridge vents for this very reason. David Link to comment Share on other sites More sharing options...
dicksob Posted May 2, 2019 Share Posted May 2, 2019 Agreed, think Ih must have recognised this as on my new van the filler point is on the other side of the van just in front of the rear wheel arch, pipe work goes to the regulator mounted just under the side door and onto the tank mounted in the middle. Feels much safer! Link to comment Share on other sites More sharing options...
daviddwight Posted May 7, 2019 Share Posted May 7, 2019 We were warned about this during hand over of our new van with lpg tank, it seems even with the fridge off the heat at the back of the fridge could cause this, if the filler point is near the fridge. It is the small amount of gas escaping when the nozzle is disconnected. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 8, 2019 Share Posted May 8, 2019 dicksob - 2019-05-02 3:47 PM Agreed, think Ih must have recognised this as on my new van the filler point is on the other side of the van just in front of the rear wheel arch, pipe work goes to the regulator mounted just under the side door and onto the tank mounted in the middle. Feels much safer! Sandalwwod’s original posting provided no details about when the ‘flashback’ occurred. The person filling the LPG tank diagnosed the cause as a gas leak and the fridge itself was said to be “turned to 12V”. Assumptions have been made that the Tio’s fridge is the ‘smart’ type and might have automatically switched to gas operation during the refilling process - but on-line information suggests that a 2012 Tio would have a Dometic ‘manual’ fridge. In the follow-up thread https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/IH-MOTORHOME-ALERT-LPG-GAS/51939/#M605799 Sandalwood mentions NCC advice about LPG fuel filler positioning. This probably relates to the NCC Code of Practice 306 that was issued in 2013 and is referred to here https://www.uklpg.org/media/DOC5A27C2D800B5D/UIS031%20-%20Motorhomes%20-%20Fixed%20LPG%20tanks%20for.pdf I don’t know what the NCC Code of Practice 306 stipulates, but I can well imagine that it includes a requirement that an external LPG refilling-point for a fixed gas-tank be a minimum distance from any appliance that can produce a spark and/or naked flame. As IH Motorhomes seek NCC approval for their products, the reason that the LPG refilling-point on your 2017 motorhome is located where it is won’t be because IH Motorhomes recognised what a daft idea it was to put the refilling-point between the fridge vents, but to permit them to comply with 2013 NCC Code of Practice 306 in order to gain NCC Approval. As far as I’m aware the NCC has no ‘legal’ status. So although it would be necessary for any motorhome manufacturer seeking NCC Approval for new motorhomes built after NCC CoP 306 had been issued to comply with that CoP, the CoP won’t apply to non-NCC Approved motorhomes. I wouldn’t expect CoP 306 to have any retrospective powers either, meaning that although anyone owning an IH Motorhomes model that has an LPG refilling-point so close to the fridge vents would be well advised to have the refilling-point relocated, they are not compelled to have that modification carried out. Link to comment Share on other sites More sharing options...
Alanb Posted May 8, 2019 Share Posted May 8, 2019 daviddwight - 2019-05-07 8:30 PM We were warned about this during hand over of our new van with lpg tank, it seems even with the fridge off the heat at the back of the fridge could cause this, if the filler point is near the fridge. It is the small amount of gas escaping when the nozzle is disconnected. I would the statement that the heat from the back of the fridge could cause propane to ignite, very hard to accept. The ignition point of propane in air is 493 C or higher, possibly depending on purity. If the fridge condenser was any where near 493 C, it would be a serious safety hazard in itself. There remains the slight possibility that perhaps the flame sensor may still be very hot, if the gas had only just been turned off. Alan Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 8, 2019 Share Posted May 8, 2019 This may be of interest http://www.center4research.org/dangerous-pump-gas-things/ While the Tio’s fridge lighting/sparking must be the logical explanation for the flashback, there are alternative possibilities. Link to comment Share on other sites More sharing options...
plwsm2000 Posted May 8, 2019 Share Posted May 8, 2019 Alanb - 2019-05-08 1:36 PM daviddwight - 2019-05-07 8:30 PM We were warned about this during hand over of our new van with lpg tank, it seems even with the fridge off the heat at the back of the fridge could cause this, if the filler point is near the fridge. It is the small amount of gas escaping when the nozzle is disconnected. I would the statement that the heat from the back of the fridge could cause propane to ignite, very hard to accept. The ignition point of propane in air is 493 C or higher, possibly depending on purity. If the fridge condenser was any where near 493 C, it would be a serious safety hazard in itself. There remains the slight possibility that perhaps the flame sensor may still be very hot, if the gas had only just been turned off. Alan The autoignition temperature of Butane (405C) is a fair bit lower than Propane. I am not sure what the Butane/Propane mix was, but it would be a lower temperature than pure Propane. I wondered if parts of the exhaust could get to this temperature (possible during a DPF regen cycle?) and would this be enough to cause ignition? On a LPG powered car, the exhaust temperature would be lower than the diesel exhaust so not such a big concern. On my motorhome, the gas filler and gas compartment are on the opposite side of the van to the exhaust pipe tail but is this always the case on other vans? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 8, 2019 Share Posted May 8, 2019 ‘Autogas’ in the UK is near enough 100% propane. The NCC CoP relates to fixed LPG tanks not user-refillable bottles, and will only apply to motorhomes built in the UK. I seriously doubt that - whatever CoP 306 advises - it won’t be necessary for a UK converter to have the LPG refilling-point on the opposite side of the motorhome to a gas fridge or heater exhaust: just that the refilling-point should be well away from such things. For their user-refillable bottle systems Gaslow advises that, when the position of the refilling-point is being decided, consideration should be given to what would happen if the hose connection on to the back of the filler should leak, that under no circumstances should gas be able to penetrate into the living area, and that leaking gas should vent to the outside. The possibilty that leakage of the hose connection on the back of the filler might occur was evidently overlooked by IH Motorhomes in 2012, as was the possibility that a Tio’s gas fridge might ignite the LPG being pumped through the external filler. I don’t think there’s any doubt that the ‘flashback’ originated behind the fridge vents as one of the vents was partially melted by the heat. Certainly with a ‘bottle system’ there’s a strong likelihood that the refilling-point will be near the gas-bottle compartment and no guarantee that a gas fridge won’t be adjacent to the gas-bottle compartment. That’s the case with my Rapido 640F - the fridge’s lower ventialation grille is adjacent to the gas-locker. I would have thought that the refilling-point for a motorhome’s original-equipment fixed LPG tank will just be positiioned where it’s convenient for the converter and user, and (hopefully) not where it’s plainly potentially lethal. Link to comment Share on other sites More sharing options...
Steve928 Posted May 8, 2019 Share Posted May 8, 2019 Perhaps the best safety improvement that could be made to LPG refilling would be the widespread adoption of the Euro fill nozzle and gun. Anyone who has used one will surely have noted that these are practically gas-tight upon connection and disconnection. Compared to the woosh of gas that the archaic bayonet connector and even the dish and acme connectors emit they are a major step forward. I doubt that there's little chance of that ever happening though, certainly not in the UK's shrinking LPG market. Link to comment Share on other sites More sharing options...
pepe63xnotuse Posted May 8, 2019 Share Posted May 8, 2019 This underslung Lpg tank lark seems a bit of a hit'n'miss affair at times... So, not only have we got gas tanks that can't easily be shut off at source, and with regulators/hoses that are in some/many cases located where they will be vulnerable to damage from road debris, we can now add that a "high end" convertor has been positioning their filling points adjacent to a source of ignition!?... Blimey.... :-S ..if only there was a way of obtaining gas in pre-dispensed containers..and distributed through a large network of outlets.... :-S Link to comment Share on other sites More sharing options...
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