To Purge or not to Purge January 28, 2005, 05:15:06 pm Yahoo Message Number: 50026GroupThis message was prompted by the discussion on what's full or not full (80%) which started with Steve K.s msg. #49989.Question: How many of you had your LP tank "PURGED" before you filled it with LP the first time? Or, did you do as I did, run just down the street and have the local building supply place 'fill' the tank? Mine registered ¾ full when I pulled out of that yard. According to the LD manual the factory "air pressurizes" the tank in order to check for leaks. At orientation Dave said that they use approx. ¼ tank of LP to check for leaks. And, that is pretty much what you have when you drive away from the Mother Ship and head down the road to get it 'filled'.Now comes the kicker... How many of you noticed or even read the little yellow pamphlet printed by Manchester Tank that came with your paperwork? In that publication it recommends that you 'purge' your tank before initial filling. It goes on to say that if the tank is not "properly" purged, air in the container dilutes the LP-gas and may cause "excessive tank pressure, slow filling and poor appliance operation of Automatic Stop Fill Valve."My local bulk LP dealer says that if your appliances, ie. stove, etc. work okay, not to worry about it. But if you have a yellow or weak flame or other problems you should take it in and they will make it right.What say you?Steve S. Lazy Bones
Re: To Purge or not to Purge Reply #1 – January 28, 2005, 05:43:54 pm Yahoo Message Number: 50028Steve,Does purging in this case refer to putting a slight vacuum onthe tank before filling such as when you have your cars airconditioning evacuated and recharged ?JC
Tank Capacities, 2000 RK Reply #2 – January 28, 2005, 06:43:44 pm Yahoo Message Number: 50032I've scoured the manual, but can't find the capacities for the black tank and gray tank on our new-to-us LD. The book does say that all LDs have approximately a 55-gallon water tank (which is quite a bit more than our old 1980 unit). I just hope the waste tanks are commensurately large! Thanks in advance for any info...Sonsie Temporary Two-LD Owner 1980 RB, 2000 RK
Re: To Purge or not to Purge Reply #3 – January 28, 2005, 06:44:34 pm Yahoo Message Number: 50033Quote Steve,"Does purging in this case refer to putting a slight vacuum onthe tank..."JC Good question JC!Actually, I was unable to get a description of what was involved in purging. I guess common sense would say that the air should be removed (by whatever means) prior to the filling process, as evidenced by the Manchester Tank pamphlet which says "Air in LP-gas containers is a contaminant."Steve S. Lazy Bones
Re: To Purge or not to Purge Reply #4 – January 28, 2005, 07:01:35 pm Yahoo Message Number: 50034lomitalounger wrote: Does purging in this case refer to putting a slight vacuum on the tank before filling such as when you have your cars air conditioning evacuated and recharged ? Basically, purging a (new) tank is just flushing it out with propane to remove any air and *moisture* before filling with LPG. I don't believe that purging creates a vacuum, but this is another question I will put to the "gas guru" when he returns!Joan
Re: To Purge or not to Purge Reply #5 – January 28, 2005, 07:59:47 pm Yahoo Message Number: 50042Quotelomitalounger wrote: Does purging in this case refer to putting a slight vacuum on the tank before filling such as when you have your cars air conditioning evacuated and recharged ?Basically, purging a (new) tank is just flushing it out with propane to remove any air and *moisture* before filling with LPG. I don't believe that purging creates a vacuum, but this is another question I will put to the "gas guru" when he returns! At Life on Wheels, Al Coho said the process of "purging" is a follows: -Using VAPOR, the tank is pressurised to about 15 psi. -The tank is then vented down to atmospheric pressure. This dilutes the air in the tank so it is now 1/2 air, 1/2 propane.-Repeat the pressurise/vent cycle. (Air now 1/4.) -Repeat the pressurise/vent cycle. (Air now 1/8.) -Repeat the pressurise/vent cycle. (Air now 1/16.) Having done this four times, the amount of air in the tank is down to about 6% of the contents of the tank.-Fill the tank with liquid propane. This compresses the remaining air in the tank into the 20% space over the top of the liquid in the tank so the percentage of air is now about 31% and the remainding 69% is propane (the rest of the propane vapor is compressed or condenses into liquid). Purging thus increases the percentage of propane well above the 2.4% to 9.5% range where it will ignite. The remainder of the air will feed out of the tank with the propane vapor. Since the air is a small portion of the vapor it will not cause any problem. The contents of the tank will become entirely propane with use.When we picked up our coach, LD had filled the tank already so we assumed it had already been purged since the appliances worked normally.Linley
Re: To Purge or not to Purge Reply #6 – January 29, 2005, 08:42:15 am Yahoo Message Number: 50072QuoteAt Life on Wheels, Al Coho said the process of "purging" is a follows: -Using VAPOR, the tank is pressurised to about 15 psi. -The tank is then vented down to atmospheric pressure. This dilutes the air in the tank so it is now 1/2 air, 1/2 propane.-Repeat the pressurise/vent cycle. (Air now 1/4.) -Repeat the pressurise/vent cycle. (Air now 1/8.) -Repeat the pressurise/vent cycle. (Air now 1/16.) Having done this four times, the amount of air in the tank is down This is basically the way it is done in the field. It is considerably less polluting to evacute and then simply fill, but doing so safely requires equipment beyond what most stations would possess. Just filling an air-filled tank with propane will almost completely remove any air through the vent, as the vapor space will at that point still be a mixture of air and the fuel vapor. Thus, appliances will work fine and the air will be diluted and removed quickly with use. However, moisture from the air contaminant will have condensed out and attached to the walls of the tank, condensing back into the propane slowly over time. At high flow rates, such as oven or furnace use, the regulator can ice up even at outside temperatures well above freezing. The ideal situation would be a tank delivered sealed and filled with dry nitrogen, after evacuation/purge cycles at the factory. This could then be simply filled with propane at the pump, without purging. The N2 will be diluted sufficiently at the first fill.Unfortunately, service station tanks are not necessarily properly maintained either, and water and other problematic contaminants can thus show up later on even in a well-seasoned tank.Steve
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #7 – January 29, 2005, 02:54:56 pm Yahoo Message Number: 50108Steve S wrote: (snip) ... How many of you noticed or even read the little yellow pamphlet printed by Manchester Tank that came with your paperwork? In that publication it recommends that you 'purge' your tank before initial filling. . . . What say you? . . . Well Steve, since you asked, I say that it's about time for you to get out and have some fun. You've been cooped up too long if you've been reading all those little pamphlets! Even getting out and shoveling the snow off your LD would be more fun than that.MMMV - Sarah Quartzsite - getting high speed wireless in lots of places - in front of a little place called City Bus Internet Cafe. Yee-hah!!
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #8 – January 29, 2005, 08:41:47 pm Yahoo Message Number: 50121Quote"...I say that it's about time for you to get out and have some fun...""...shoveling the snow off your LD..."QuoteSarah SarahHey, we're heading out next week and it can't be soon enough.But bite your tongue, never will a single flake of snow fall upon these Lazy Bones. Unless of course we are over 6,000 ft. and it's opening day of trout season! :>)Steve S. Lazy Bones
To Purge or not to Purge Reply #9 – January 28, 2005, 07:18:32 pm Yahoo Message Number: 50036Question: How many of you had your LP tank "PURGED" before you filled it with LP the first time? Wouldn't Lazy Daze have done this before putting propane in the tank for their tests? If not, then, no, we have never had our propane tank purged -- nor did we on any of our previous RV's. Have never had any problems with the propane.Linda & Earl 2004 23.5' Red TK From Quartzsite, AZ
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #10 – January 28, 2005, 07:29:50 pm Yahoo Message Number: 50039Linda & Earl Hylton wrote: Wouldn't Lazy Daze have done this before putting propane in the tank for their tests?I don't think so; they just put in about 1/4 tank or less, just enough to test the system. When I took delivery, I used up as much as possible of what LD had put in, then had the local Suburban guy "purge" and re-fill.Joan
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #11 – January 28, 2005, 09:52:14 pm Yahoo Message Number: 50055Quote Linda & Earl Hylton wrote:Wouldn't Lazy Daze have done this before putting propane in the tank for their tests?I don't think so; they just put in about 1/4 tank or less, just enough to test the system. When I took delivery, I used up as much as possible of what LD had put in, then had the local Suburban guy "purge" and re-fill.Joan Considering that propane is heavier than air, and that the tank gas outlet is up high where any non-purged air would be, I suspect that LD does in fact purge the tank when first filled. If they didn't, they'd have a tough time getting the appliances to work.AFAIK, purging is simply releasing enough air to get rid of it all and to have propane come out of the tank when the tank is first filled.all the best,bumper
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #12 – January 29, 2005, 03:09:35 pm Yahoo Message Number: 50109QuoteMMMV - Sarah Quartzsite - getting high speed wireless in lots of places - in front of a little place called City Bus Internet Cafe. Yee-hah!! Sarah, we're back home from hanging out with the Boomers. Are you still out with the WIN's? We need to meet!Linda & Earl 2004 23.5' Red TK From Quartzsite, AZ
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #13 – January 29, 2005, 07:33:28 pm Yahoo Message Number: 50116. . . Sarah, we're back home from hanging out with the Boomers. Are you still out with the WIN's? We need to meet! . . .Yes. I couldn't find the Boondockers, so we're back with the WINs. We're going out to the Desert Bar in the morning at 11 - don't know what time we'll be back. What's your Sunday evening like? I think we're going back to Yuma Monday to get the Honda from the dealer.Sarah[Non-text portions of this message have been removed]
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #14 – January 29, 2005, 09:19:29 pm Yahoo Message Number: 50124What's your Sunday evening like? I think we're going back to Yuma Monday to get the Honda from the dealer.Sunday is clear for us. Give us a call.Linda & Earl 2004 23.5' Red TK From Quartzsite, AZ
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #15 – January 30, 2005, 07:59:52 am Yahoo Message Number: 50129"What's your Sunday evening like?" Folks, I think this kind of personal conversation might be more appropriate in private email, since it doesn't really concern the rest of the group.Andy Baird
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #16 – January 30, 2005, 08:02:42 am Yahoo Message Number: 50130Amen. Thank you.
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #17 – January 30, 2005, 10:38:35 am Yahoo Message Number: 50140OK - we don't have a car, so we could drive the LD to your place this afternoon, or you could come out here and get us. Our plan is to head back down to Yuma tomorrow morning. Whadda think?
Re: [Life With A Lazy Daze RV] To Purge or not to Purge Reply #18 – January 30, 2005, 10:42:25 am Yahoo Message Number: 50141Whoops!! Sorry about that - I forgot to pay attention to whom I was sending it. Mea Culpa! Sarah
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