# what pressure for your gas regulator ?



## lebesset (Jun 17, 2013)

I often read here enquires about what gas goes with what regulator on motorhomes /caravans , especially with regard to the current 30mb regulators for both both butane and propane 

frankly it doesn't seem to matter !! I have 27/30/37 regulators have have use them all with both gases with no problem ; I also have  50mb regulators which have come from old german motorhomes , and although I have also used them without problems I don't suggest their use 

one of my neighbours has  had a problem with his truma water heater , so I stripped it down for him ; I note that it has a label telling the correct pressure to use ..... 27, 30 or  37 

 motorhome appliances will all work on a range of regulators , if you think about it , they have to , the pressure from the bottle will vary according to the temperature AND the volume remaining


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## Covey (Jun 17, 2013)

I have a 1997 Hymer S700 and that was manufactured with all Truma 50mBar gas regulators and appliances.  The original individual gas bottle regulators were replaced with a single changeover/regulator unit some years ago and Truma stopped the concept of a regulator on each bottle. The standard German gas pressure was 50mBar.

Truma now produce a unit called a DuoControl.  This is a combined bulkhead mounted auto changeover and regulator.  There are two pressure versions, 50mBar and 30mBar and Truma make a version designed for those who want to use gas on the move called the DuoControl-CS.  The DuoControl-CS and the basic static DuoControl are fitted to motorhomes, caravans and trucks.

Because the gas at the BBQ point is 50mBar, you have to make sure that your BBQ is 50mBar!..  I bought a Cadac Safari Chef a couple of weeks ago which because it was UK supplied came with a 30mBar jet. Cadac very kindly sent me a 50mBar jet FEE OF CHARGE which was a nice surprise!


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## vindiboy (Jun 17, 2013)

lebesset said:


> I often read here enquires about what gas goes with what regulator on motorhomes /caravans , especially with regard to the current 30mb regulators for both both butane and propane
> 
> frankly it doesn't seem to matter !! I have 27/30/37 regulators have have use them all with both gases with no problem ; I also have  50mb regulators which have come from old german motorhomes , and although I have also used them without problems I don't suggest their use
> 
> ...


  Well the last part of your post is incorrect, Regulators   do just that, they ensure the gas is fed to  your appliances at a  regular constant  pressure.


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## lebesset (Jun 17, 2013)

vindiboy said:


> Well the last part of your post is incorrect, Regulators   do just that, they ensure the gas is fed to  your appliances at a  regular constant  pressure.



if you run a pressure test [ which I have ] you will find that there is a variation ......in fact my water heater will stop working when the pressure drops , but the fridge keeps going ; a regulator is only an approximate device as you would expect from such a crude device

if you want a constant pressure output you have to fit a 2 stage regulator , not what is fitted on a motorhome


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## outtolunch (Jun 17, 2013)

The pressure at the appliance will be less than at the regulator depending on size and length of pipework and how many bends and valves in the pipe run.

when I got my motorhome it was fitted with a calor propane bottle and a 37mb regulator and this has now been changed to a 50mb regulator because that was its original requirement and in all the paperwork supplied there was no reference to being converted to a lower pressure only the original gas certification and since changing the problems I had with lighting the heater have been cured the flame on the hob is better and after having to de-soot the fridge flue this also works better.
Also found in the bits and pieces supplied in the van a 50mb butane LH screw regulator a rare beast in this country but the previous owner had picked it up from Spain.


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## runnach (Jun 18, 2013)

There is no need for twin stage systems in a motorhome, The benefits of a twin stage system is on domestic LPG tanks it assists in the pipe run from tank to property considering there is often a significant distance.

Single stage regulators reduce on propane from 6.8 bar in the bottle to 37 mbar a significant stepping down. Temperature part empty bottles should have no affect.

Pressure at the appliance will be lower due to pipeline resistance as already suggested, There are permissible pressure drops ( EN1057).

An often overlooked factor, is that when appliances are being used particularly in combination, different size bottles can only cope with a given" take off" rate which will adversly affect performance. all part of the mix when designing a system.

Channa


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## vwalan (Jun 18, 2013)

come on channa tell us about the overlap of the regs and how wide the scale of a reg is . thayt explains it all .its very interesting . seriously .


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## runnach (Jun 18, 2013)

vwalan said:


> come on channa tell us about the overlap of the regs and how wide the scale of a reg is . thayt explains it all .its very interesting . seriously .


 I dont understand your question exactly, assuming its not a pith take.

Channa


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## vwalan (Jun 18, 2013)

no .you have in the past talked about the lowest and highest lock off pressures of regulators . and how the butane 28mb over laps a 37mb regulator etc . i should have kept it . i found it very interesting .


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## Tow Itch (Jun 18, 2013)

A technical input from Mr Channa. I do like technical inputs.
 What I find hard to comprehend is that if burners were designed for optimal performance with propane at 37mbar and butane at 28mbar then no matter what is done the varying gasses should be presented in those pressure ratios. On the new common regulators the pressure of propane is 19% lower (Or 37mbar is 23% higher) than previously butane being 7% higher in pressure. I'd love to know why this pressure was chosen was it a safe limit to over fuel butane and a performance drop was accepted off propane?
 I can see that you can design jets to cope with a different pressure of the same gas e.g. 50mbar in Germany.

 Or have I misunderstood things even though our French cousins also choose 28mbar and 37mbar is 50mbar used for both gasses in Germany if so are the disadvantages as imagined one gas over fuels and the other under fuels or did we choose the pressure ratios for other reasons?


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## runnach (Jun 18, 2013)

Now I understand, perhaps for the benefit of newer peeps I need to explain what we mean by "lock up "

The term simply means that the gas supply to the motorhome is turned on,but there is no gas demand from appliances within the system. The diaphragm within the regulator lifts with the increase in pressure within the pipework this in turn closes the the inlet valve on the regulator stopping the flow of gas."lock up " is also known as static pressure and standing pressure.

Traditionally, Butane has run at 28 mbar and Propane at 37mbar. However after lobbying in 2002 the caravan and motorhome industry decided to go with a regulator of 30 mbar.

BS EN 12864 / 13786 dictates permissable deviations from the nominal set outlet pressures, Which in effect is + 10 mbar.

The reality is I have never seen a Butane regulator lock up at 38 mbar normally I would expect 31/32 mbar. With a propane regulator 38.5 mbar.

A 30 mbar regulator typically locks at 32 mbar, 

So in essence the 30 mbar regulator accomodates both gases.

I have asked the question here for pure academic interest if anyone had noticed a discernible difference running propane on 30 mbar ( in theory pressure has been reduced by 20% or thereabouts)and no one had noticed any difference.

Propane is a better gas for winter as we all know, because it will gas right down to -47 degrees, yet it has a lower calorific value ( bang for buck) hence a higher working pressure to compensate.

Channa  


hopefully Mr Tow Itch my post answers your question, and your question was the very reason I asked re second last paragraph


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## vwalan (Jun 18, 2013)

thats it channa .i knew you had figures . i have used butane and propane on 28mb and 37mb regulators still havent noticed any trouble . 
there was a time in morocco they would only put propane in our uk bottles .clipon . had no choice but run propane. once they put butane in my propane bottle .why i dont know but it worked . 
in some countries i have been in you had to tip from one bottle to another what gas didnt matter it was gas .you could cook . i dont recommend doing it though in case there is a prob .better try to keep it right . if you can . thanks channa .must try and remember your figures .


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## runnach (Jun 18, 2013)

vwalan said:


> thats it channa .i knew you had figures . i have used butane and propane on 28mb and 37mb regulators still havent noticed any trouble .
> there was a time in morocco they would only put propane in our uk bottles .clipon . had no choice but run propane. once they put butane in my propane bottle .why i dont know but it worked .
> in some countries i have been in you had to tip from one bottle to another what gas didnt matter it was gas .you could cook . i dont recommend doing it though in case there is a prob .better try to keep it right . if you can . thanks channa .must try and remember your figures .


 Hi Alan, the clue is in EN European Norm , other parts of the world god knows what they get up too....lol Morocco Africa and all that.

Anyway bottom line is any lad from Warmsworth,Balby ,Skellow, Carcroft  And Stainforth, should have enough nouse to get by .....:dance::dance:
Channa


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## lebesset (Jun 18, 2013)

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## vwalan (Jun 18, 2013)

hi lebe.its got so expensive to fill non maroc bottles its now cheaper to get a maroc and throw the bottle away . 
mind dont you will need it again for sure . 
i think it got that many turning up it took two men all day just filling spurious bottles . 
several of the other gas plants have stopped doing it as well. 
the maroc bottles are still 45 dirham as far as i know was 3 quid now more like 4,50. but cheap. 
maroc is a good place for adjustable regs as well . i payed just under 2quid for one last time i was there. butane nut fitting .


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## vwalan (Jun 18, 2013)

Gas Cylinder Adaptor

undefined	Adaptor for connecting male POL UK regulators or fittings to cylinders with male 21.8 mm SI fittings, which are found on some UK butane cylinders and various cylinders around the world. Supplied with nitrile washer for butane end connection.
5⁄8" BSP-LH female POL x 21.8 mm SI-LH female.
	Part No.	Description	Unit Price	Qty
	21123 	Butane x POL	£3.17 	
hi lebesset this could be usefull to you if you came over here . i find another use for it but we wont go there . this is from bes.co.uk


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## Tow Itch (Jun 19, 2013)

> hopefully Mr Tow Itch my post answers your question, and your question was the very reason I asked re second last paragraph



 Not sure if your answer did. If saying that 





> I have asked the question here for pure academic interest if anyone had noticed a discernible difference running propane on 30 mbar ( in theory pressure has been reduced by 20% or thereabouts)and no one had noticed any difference.


Large portions of the world population notice nothing more subtle than been hit in the face with a brick. I would have thought personal observation was a poor way to research this. There must be technical data on the subject. My initial thought was that it would slow heating with propane. As a secondary thought I was also interested in the prospect of overfueling on butane. The best pieces I have read on CO poisoning stress that CO poisoning isn't just about waking up dead but low level chronic poisoning results in some really not nice side effects. Most expedition quality stoves have flames where the complete combustion is interrupted by the level that the cooking vessel is suspended at and that raising the height of the vessel by an inch can drastically lower CO output.(This concept is well known from instantaneous gas hot water heaters)  The highest CO outputs came from liquid fuelled stoves but there were some significant gas CO emitters. For most of us who cook for a short period have good ventilation in summer and are at sea level this would not be an issue. Then take Alan with a possibly overfueling stove at altitude it's cold so doors are shut and the overfueled stove has reduced oxygen (Altitude) and Alan's oxygen level is naturally lower (Altitude). A possible recipe for chronic poisoning.  

FAQ - Technical Details on Stoves Zen Backpacking Stoves - Carbon Monoxide Hazards These are not 5 minute reads but top info if interested.

 I meant to post some questions on this and other gas questions to a chappie who advises on gas especially water heaters on UK Campsite never got round to it.

 The lower calorific value of propane is something I either fundamentally misunderstand or many others do. (This is rushed I did a better job at some point in the past) There is a difference between theoretical values and likely values. So if I use the figures given by Calor they are given as per cubic meter Butane 126Mj/m3 Propane 95.8Mj/m3 but we don't sell gas per m3 we sell per Kg. The gas in the m3 of butane has a greater mass than the m3 of propane. Butane C4H10 58.12 g/mol* Propane C3H8 44.01g/mol* so butane "weighs" 1.32 times as much as propane. 126/1.32=95.45 so per kilo the calorific value is about equivalent. Coincidentally if I divide 37(mbar) by 1.32 I get 28.03(mbar) So if I'm using the "antiquated" regulators I get the same calorific delivery per second? (Not being a smug twat just realised where the 2 differing pressures come from) I just price per Kilo. To be honest I just try to buy cheap propane. 
Think I answered my own question this was by accident not design I've never worked out that the relationship between the pressure and the relative molecular weights. 

Butane | Calor Gas Butane | Calor Gas Molecular Weight - Gases and Vapors  *Volume to weight one mole (gramme atom) of a gas at standard temperature and pressure occupies 22.4 litres hence for any two gases if given a value proportional to volume one can proportion on mass

 Sorry to refer to another thread but I never got a reply from our standard French correspondent.  Referring to http://www.wildcamping.co.uk/forums...me-chat/29589-more-questions-about-gas-4.html Can you really buy 13Kg of butane or propane for €9  Tarif Bouteille Gaz Domestique, Prix Cube propane, Vente Bouteille de Gaz Butane - Butagaz


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## lebesset (Jun 19, 2013)

Tow Itch said:


> Not sure if your answer did. If saying that
> Large portions of the world population notice nothing more subtle than been hit in the face with a brick. I would have thought personal observation was a poor way to research this. There must be technical data on the subject. My initial thought was that it would slow heating with propane. As a secondary thought I was also interested in the prospect of overfueling on butane. The best pieces I have read on CO poisoning stress that CO poisoning isn't just about waking up dead but low level chronic poisoning results in some really not nice side effects. Most expedition quality stoves have flames where the complete combustion is interrupted by the level that the cooking vessel is suspended at and that raising the height of the vessel by an inch can drastically lower CO output.(This concept is well known from instantaneous gas hot water heaters)  The highest CO outputs came from liquid fuelled stoves but there were some significant gas CO emitters. For most of us who cook for a short period have good ventilation in summer and are at sea level this would not be an issue. Then take Alan with a possibly overfueling stove at altitude it's cold so doors are shut and the overfueled stove has reduced oxygen (Altitude) and Alan's oxygen level is naturally lower (Altitude). A possible recipe for chronic poisoning.
> 
> FAQ - Technical Details on Stoves Zen Backpacking Stoves - Carbon Monoxide Hazards These are not 5 minute reads but top info if interested.
> ...




who told you you could buy 13Kg of gas from butagas for €9 ? have a look in your french dictionary for consignation , having been here for 25 years I don't need to look lol


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## Tow Itch (Jun 19, 2013)

> who told you you could buy 13Kg of gas from butagas for €9 ? have a look in your french dictionary for consignation , having been here for 25 years I don't need to look lol



 No one did. I saw the referred piece and then asked twice in a thread about it. I asked here again. Why not do something really silly and just tell me. I have some abilities but am no linguist. (cunning or otherwise) Consignment doesn't tell me an awful lot. Is it the bottle deposit prices for that company? Why not look at the original thread, which was written trying to assist someone and the degree of incredulity I had at that price? I apologise so at leaving the preamble out on the 3rd or 4th time of asking.

 This is your thread and original question. Hopefully you have learned something from the responses. Why not extend the cycle of group help by assisting me when I ask on a not unrelated matter. I posed the question especially to our French correspondents it was asked simply because I thought there was going to be something I didn't understand.


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## runnach (Jun 19, 2013)

Calorific value of Butane is 3200 btu per cubic ft/ 121.5 mj per cu/ m 
Calorific value of Propane is 2500 btu per cubic ft/ 95mj percubic meter.

Clearly the calorific value i.e amount of energy released when a known quantity of gas is BURNT. is higher with butane than propane.

I dont see the value of translating facts and figures to KG weights,on the basis the liquid gas "boils" and vaporises to a gaseous state and per cubic metre, or cubic foot of volume, Butane offers more bang for the buck, However in cold weather has difficulty gassing.

It is therefore reasonable that to accomodate a "weaker" fuel perhaps we need more of it , hence a system charged at 37 mbar as opposed to 28 mbar.

 Im not sure where the refilling butane part of your post or co emmissions came about 


Channa


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## lebesset (Jun 19, 2013)

Tow Itch said:


> No one did. I saw the referred piece and then asked twice in a thread about it. I asked here again. Why not do something really silly and just tell me. I have some abilities but am no linguist. (cunning or otherwise) Consignment doesn't tell me an awful lot. Is it the bottle deposit prices for that company? Why not look at the original thread, which was written trying to assist someone and the degree of incredulity I had at that price? I apologise so at leaving the preamble out on the 3rd or 4th time of asking.
> 
> This is your thread and original question. Hopefully you have learned something from the responses. Why not extend the cycle of group help by assisting me when I ask on a not unrelated matter. I posed the question especially to our French correspondents it was asked simply because I thought there was going to be something I didn't understand.



sorry about my little joke , but I often find people find it clearer when they look it up themselves , you will have noticed how often the same questions come up 

but I didn't start this thread to try to learn anything ,the question was rhetorical , as an industrial chemist in my former life most things had passed my way ; rather it was an attempt to clarify matters for those who are concerned about doing the wrong thing on a safety critical item , just a little reassurance


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## lebesset (Jun 19, 2013)

david , earlier thread I quoted the fact that , when forced to change to 30mb when all your appliances were fitted to run at 50mb , you didn't report any problems 
would you care to comment on that ?


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## Tow Itch (Jun 19, 2013)

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## runnach (Jun 20, 2013)

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## lebesset (Jun 20, 2013)

should I be sad or happy that I started this thread ..it seems to be going on a bit !

just to summarise a few things regarding lpg's 

the dictionary definition of a monopoly is that one supplier has a very large percentage of a market and they are in effective control of the market ; this is the position in the UK and Calor exploit it to the full in their pricing policy 

when I came to france in the 1980's there was another situation , a cartel , a common arrangement allowed by the government as long as the companies were french ; at the time the deposit on a bottle was FF200 [ £20 ]  ; but in the last decade  the cartel was broken ,first Repsol came in selling gas in southern france at lower prices and no deposit [ only in the south as they could return the empties to their northern spain factories for refilling and avoid the cartel ] ; more recently some big retailers have come in with own brands and gas is available from them at even lower prices , forcing down  prices to the levels of 15 years ago ; bottle deposits are commonly €1 as noted by david ...they have exploited a niche in the market introducing a 9/10 Kg standard thread [ like calor 4.5 Kg butane dumpy ] bottle , good news for uk motorhomers with 6/7Kg Calor bottles as the size is virtually identical

we like competition !

we have had an expert explanation from channa about cut off's showing why the 30mb for all works , and personal experiences of how 27/30/37 regulators will all do the job for both gases ; although I observed in my original post that I have used 50mb regulators on all equipment without problems I stated that I don't suggest this , I regard it as dangerous except on equipment designed for it , and that the aforesaid  27/30/37 regulators are the ones to use in safety with either gas on all equipment 

a factor I haven't seen discussed is that there are available  regulators which will allow varying volumes  of gas at their designated maximum pressure , clearly it is necessary to fit one to cover the appliances fitted ; I would guess [ no more than that ] german / scandanavian manufacturers used 50mb to provide more easily gas volumes for their more severe climate but now fit 30mb with a higher maximum throughput ; I personally [ and alan I think ] have regulators with adjustable volume control ] ; so I surmise that a 27mb regulator works fine with propane as long as the throughput required is within it's capacity , and maybe winter heating would not be at 100 % [ I haven't been in the uk except between june and october for 25 years , and head south from france in the winter ! ] so I always use butane !

re gas prices ...In france I use 10Kg Energas bottles from Intermarche in france , last one I swopped cost me €16.50  so £1.40/Kg ; this is the same price per litre as refilling from the lpg pump at the garage

in spain I use 12.5Kg Repsol bottles , I understand that there has been a hefty increase in the price this month to €17.50 [£14.80 ] so £1.20 /Kg which is cheaper than at the lpg pump ; bottled gas prices are regulated in spain ...people will try and tell you the price is subsidised , but the reality is that almost half the price is TAX ! some subsidy 

alan will be along in a minute and tell us how much cheaper gas is in maroc !

can I quote lorraine chase at this point ?


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## runnach (Jun 20, 2013)

David,

A couple of points, 

Firstly my comments were in respect of standards, not my personal opinion. I was sharing the current EN standards.

The equipment fitted to German vans may straddle the European markets,be produced anywhere in the world, but that doesnt  detract from Germany traditionally used 50 mbar for the domestic market.And equipment supplied new at the point of installation is often supplied with Natural Gas (21 mbar) or a set of LPG jets.. Manufacturers despite your insistence do it for a reason.....for the German domestic market 50 mbar which as per my original suggestion is optimum efficiency and suspect was supplied.


In respect of Bureau Veritas whom randomly checked our installations in France, Or ACS in this country who sub contract the Gas Safe franchise, on the basis we issue landlords certificates, or Gas Safe themselves from what I am told from a chap I do a little work for NONE inspect jetting, they are more concenred with adequate ventilation and Gas tightness testing etc......I question all their credibility beyond being a money making excercise at times to be honest.

There is no difference in the safe installation and operation of gas appliances, whether domestic or leisure markets , both incorrectly fitted can kill at worse so Im working out why you feel a need to differentiate.

In your case it doesnt surprise me you have a good flame picture in effect the jet is oversized and if there is an issue you may be using a touch more gas than you need to.

Carbon Monoxide poisoning is the result of poor combustion as you are aware, and likely when the primary and secondary jets cant entrain air correctly, providing the gas has sufficient oxygen to entrain within its lower and higher explosive limits CO shouldnt present a problem.

In respect of an oversize jet providing there is sufficient oxygen for the combustion process, everything remains status quo in terms of emissions  However flame picture may be higher than normal 

Channa


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## runnach (Jun 20, 2013)

lebesset said:


> should I be sad or happy that I started this thread ..it seems to be going on a bit !


 Give over, we maybe talking a lot of old "gas", the alternative in the bar is Jeremy Kyle or Judge Judy .....I'll stick to gas thanks 

regards 

Channa


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## runnach (Jun 20, 2013)

If your van David had a 30 mbar regulator originally , then perhaps the jets have already been changed. At the moment I dont have time to check on the BS /En standard the original picture only shows me the flow rate the new regulator clearly states a 30 mbar regulator with the same flow rate.

Out of interest, in the Gite you have, do you have to have a landlords certificate like you would in the UK ?

I found for the mobile market that wasnt the case French arent quite as strict ( reduces ones value in the market ) I worked for a Uk company dealing with Uk customers ( contract concluded in the UK ) so we had to issue landlords certificates.

However the French are stringent as are we ensuring anyone working on Air Con systems are F gas certified ( Kyoto protocol etc ) hence the reason I returned to the Uk to qualify in air conditioning. Even the Italians are towing the line.

All interesting stuff and I maintain far more stimulating than Judge Judy and that Kyle chap.

Possibly more interesting than relieving my partner now at the bar and witnessing the local soap operas ....roll on 11 .00 pm 

Channa


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## Tow Itch (Jun 21, 2013)

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