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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#41
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Initial fill of new Propane tank fact or fiction on purge needed
On Thu, 18 Dec 2003 19:31:09 -0600, Richard J Kinch
wrote: writes: Gasoline tanks are vented to atmosphere when they are filled - so they purge themselves. Obviously not, if they are open to the atmosphere. Exactly. As the fuel goes in, the air is displaced, "purging" the tank. A propane tank is NOT open to the atmosphere, so any air in the tank stays there. |
#42
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Initial fill of new Propane tank fact or fiction on purge needed
A new tank gets purged - period - at least here in Canada. Purging where I
live consists of a brief crack of the fill valve. Then disconnect and open the tank to vent to ambiant pressure. Done. No charge. All portable tanks (20 to 100 Lbs). are filled on a scale. Every time a tank is filled (here) the attendent checks the date stamp on the tank *and* the physical condition of said tank.. A tank that had been re-painted, is too rusty, dented etc. may be refused. Aluminum paint is automatically rejected! On a lighter note; What is it about propane that triggers this group? I think I will call this phenomenon the 'King of the Hill' syndrome. Regards. Ken. |
#44
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Initial fill of new Propane tank fact or fiction on purge needed
writes:
Gasoline tanks are vented to atmosphere when they are filled - so they purge themselves. Obviously not, if they are open to the atmosphere. Exactly. As the fuel goes in, the air is displaced, "purging" the tank. A propane tank is NOT open to the atmosphere, so any air in the tank stays there. No, this is not purging. Even a "full" gasoline tank has some headspace containing a mix of fuel vapor and air. A near-empty automotive fuel tank will contain a large headspace with a potentially explosive fuel-air mix. |
#45
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Initial fill of new Propane tank fact or fiction on purge needed
You sure it was presssurized with a gas so that it didn't
need to be purged? Stan Schaefer wrote: (Roy) wrote in message ... Just what is involved with filling a new propane tank. I just bought a brand new 100# tank. Took it to a gas supplier to get filled, and they want a $25.00 initial fee supposedly to purge it..........what gives. If its empty its empty. Its got the standard type of valve (OPD not required on a 100# cylinder) so it can be opened and any air inside can be vented to the atmosphere. Am I missing something here? Called two others and they also said the tank needs to be purged since its new.........I have bought new 20# and never had to have them purged . I smell a rip off for some reason. Maybe I just need to transfer some gas to give it a used smell into this new cylinder and then act like its been filled before. Visit my website: http://www.frugalmachinist.com Opinions expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy. I've bought several new propane tanks, they've all had to be purged. You DO NOT want air mixed with your propane in there. Purging amounted to opening up the bleed screw while propane pumping was going on, screw remained open until propane fogged out of the opening. The tanks were then filled to proper weight. I got to pay for the propane that escaped, there was no extra charge for the filling station guy having to use his screwdriver. You got ripped off. On two of the new tanks there was considerable air pressure in the tank before they were even hooked up. The last one I bled down before hauling it over to the rental place where I get tanks filled, took less time that way. It took about 15 minutes for the 60 lb tank to quit passing air after I opened up the screw, there must have been a lot of pressure in there. I suppose they use it for checking for leaks after assembly, probably roll them through a water tank after pressurizing and look for bubbles at the joints. At least being pressurized that way assured me that it wouldn't leak when filled. You need to find another, more honest, supplier. Stan |
#46
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Initial fill of new Propane tank fact or fiction on purge needed
I buy butane in bulk, and add 200 millileters ethyl mercaptan to 7,500
gallons going into the bulk tank with a draft attachment for scenting. This is to prevent contamination of the transport truck, as they haul different varieties. I'm told by my supplier that tomato juice will kill the smell about as quick as anything will. He related a story about an employee accidently dropping a barrel of mercaptan from a handcart and the barrel split. After evacuation of the area, they called in two 8,000 gallon loads of tomato juice and sprayed all over the compound. He said the cleanup of the juice was a bitch in and of itself. RJ "Bob Engelhardt" wrote in message ... Mark wrote: ... This article touches on these subjects: [odorant fade] http://www.brucegoldfarb.com/propane.htm ... Good article - I never knew that the odor could fade so easily. However, it certainly is in contradiction with my experience, which is that the ethyl mercaptan odor is damn difficult to get rid of. Although my experience is generally with older tanks that probably have had continuous use. Bob |
#47
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Initial fill of new Propane tank fact or fiction on purge needed
Backlash wrote:
I buy butane in bulk, and add 200 millileters ethyl mercaptan to 7,500 gallons going into the bulk tank with a draft attachment for scenting. This is to prevent contamination of the transport truck, as they haul different varieties. I'm told by my supplier that tomato juice will kill the smell about as quick as anything will. He related a story about an employee accidently dropping a barrel of mercaptan from a handcart and the barrel split. After evacuation of the area, they called in two 8,000 gallon loads of tomato juice and sprayed all over the compound. He said the cleanup of the juice was a bitch in and of itself. I've heard that the odor is so strong and so bad close up that it can cause people to become physically ill. Is this true? |
#48
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Initial fill of new Propane tank fact or fiction on purge needed
Ken Davey wrote: On a lighter note; What is it about propane that triggers this group? I think I will call this phenomenon the 'King of the Hill' syndrome. I don't know, Some of what's been posted is accurate but lots of this 'information' is inaccurate. And purging a gasoline tank? What a troll! I don't miss working with propane. Not because it can be explosive or that it boils 44 degrees below 0, could be an interesting situation where your feet are being frozen solid while the rest of you is betting burnt to a crisp. After some of the stuff I worked with i the Military and in aviation propane is pretty pussy. I don't miss working with propane because of the customers and some of the Yahoos I worked with. 99% of the people who have propane either live in trailer parks or live someplace without natural gas service. The reason there isn't NG service is because they live in the middle of nowhere. Enough of the customers kept chickens and cows in the house. Bobtail drivers need to know the area, how better to know an area than to have grown up there. Who were these people ? The ones living in chicken and cow houses. Ok, so maybe this is an exaggeration. But it sure seemed like it. Then there were the drive in customers, those bringing small cans (up to 100 lb.) and motor homes. There's the guy who wants me to put a little extra, AKA do an overfill, in his 20s because he's going hunting and doesn't want to run out. I tell him I can't do that, he says the other guy does it all the time. ?? Reallllly? and whose this other guy? He describes a co-worker. I say I'll have to ask him about that but no, I'm not going to overfill. The guy gets ****ed off. I tell him he's lucky I filled the tank he painted black but since it's winter I think it will be Ok. Now that becomes an issue. Then there are the people who bring cans in that are rolling around the trunk of their car. And they expect to leave that way. When your doing a cylinder exchange ar HD or the local cig and beer stop they don't see how you bring them in or how you leave with them so their asses are covered. Unfortunately our fill stations were *right there*, I could see. Try telling someone that's 'always done it this way' and the 'other guys' never said anything (see chicken and cow houses) the dangers of unsecured tanks and transporting a tank with the relief valve in liquid, and how your (I'm) not going to be responsible for the law suit. Not to mention how your not to transport cylinders in an enclosed area or passenger compartment. There was the young punk who pulls up to the dock (where motor fuel tanks are filled) in his bosses dump truck and literally throws the tanks on the dock. Talk about a sky rocketing stress level! I ask if he's aware of the possibility that throwing cans around could cause a fire and we could get burnt. He says, this is no ****: We all got to die sometime. I failed every can on a visual. Then there are the roofers. Roofers use high btu torches so in colder times of the year their tanks frost off. As the torch is dyeing they turn the torch on the tank. I've seen paint pealed from the heat. I had one roofer tall me how sometimes they get the can so hot the relief valve blows off, and boy that's neat if a little too exciting. Amazing none of them got killed. How do roofers get the empties (sometimes there still half full because of frost off) off the roof? They drop them. Lots of foot and head ring damage, lots of dents and gouges. Failed damned every tank they brought me once. So they bought some new ones which I purged and filled and failed the next time I saw them because of the char marks and dents. This story has a bright spot as the roofers bought their own dispensing station so they wouldn't have to put up with me. Cool, we can't be responsible for tanks they fill. Then theirs the motor fuel/ motor home people. They pull in and first question from me is anyone in the motor home. For the most part their unprepared for this. They answer yes next words from me are everyone has to be out of the motor home before I can fill it. For the most part that's news to them. Noone in (pick a state) makes us do this. Yeah, I know, but not only is it the law but it's also a good idea. Some people want to argue. Sometimes they say no ones in the camper/ motor home and while I was filling the tank I feel the home start rocking. Their whole families inside, they didn't want to be inconvenienced. I've even had people get offended when I say removal of their pets are optional, seems they want me to think their pets are as valuable as humans. Then there's the placard issue. Read one way you count only the LPG, read another you count the can and LPG. The first way 3 33's can be carried, read another only 1 33 can be carried. I doubt the people who wrote the law understand it. Working with LP wasn't bad, working with the people who use it was unacceptable. -- Mark N.E. Ohio Never argue with a fool, a bystander can't tell you apart. (S. Clemens, A.K.A. Mark Twain) When in doubt hit the throttle. It may not help but it sure ends the suspense. (Gaz, r.moto) |
#49
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Initial fill of new Propane tank fact or fiction on purge needed
Eastburn wrote: 3. If free water is present in the container, it should be drained. Hum - now with the new OPD valve - item 3 requires the valve be taken off. Actually #3 would require the removal of any valve. OPD or otherwise. -- Mark N.E. Ohio Never argue with a fool, a bystander can't tell you apart. (S. Clemens, A.K.A. Mark Twain) When in doubt hit the throttle. It may not help but it sure ends the suspense. (Gaz, r.moto) |
#50
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Initial fill of new Propane tank fact or fiction on purge needed
Stan Schaefer wrote: I've bought several new propane tanks, they've all had to be purged. You DO NOT want air mixed with your propane in there. Purging amounted to opening up the bleed screw while propane pumping was going on, screw remained open until propane fogged out of the opening. The tanks were then filled to proper weight. Wrong. Very wrong. That was an improper purge, and if liquid was coming from the bleeder valve it was already near or at capacity. The last one I bled down before hauling it over to the rental place where I get tanks filled, took less time that way. It took about 15 minutes for the 60 lb tank to quit passing air after I opened up the screw, there must have been a lot of pressure in there. I suppose they use it for checking for leaks after assembly, probably roll them through a water tank after pressurizing and look for bubbles at the joints. Nope. The tank had either dry air or N2 in it to prevent air and moisture from entering the tank which would cause rust and odorant fade. You really did yourself no favor by bleeding it off. Read my previous post on odorant fade, open the link and read the article if my words not good enough. -- Mark N.E. Ohio Never argue with a fool, a bystander can't tell you apart. (S. Clemens, A.K.A. Mark Twain) When in doubt hit the throttle. It may not help but it sure ends the suspense. (Gaz, r.moto) |
#51
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Initial fill (should have looked before I asked)
Loren Coe wrote: the one metro propane distributor in N.Dallas used both scale and meter to fill bbq tanks. he never looked at the meter, just took the printout and handed to the customer. although a flat rate, the office wanted that ticket. I hope they also opened the bleed valve. Whether it's a portable, motor fuel or stationary tank the bleed valve must be opened. The bleed valve is attached to a dip tube. The dip tube extends into the tank like a stand pipe in reverse. The bleeder valve spits when a tank is filled to it's designed capacity. If you need to know the designed dip tube length look at the collar on the tank. There will be a stamping: D.T. XXX where the XXX is the length of the needed tube. As I said the bleeder is to be opened every time the tank is filled. Period. Scales are known to be inaccurate, OPDs are not to be trusted. The dip tube is always right, assuming it's in place and the proper length (I have a story about my former boss and dip tubes which I will spare you, take my word that sometimes the wrong ones are installed). A missing dip tube is somewhat rare. Listen while your tanks being filled. If a tank fills to 100% it makes a very distinctive blooeeep sound. If you pick up your tank and shake it and you can't feel the fluid sloshing it's been overfilled (or it's empty). -- Mark N.E. Ohio Never argue with a fool, a bystander can't tell you apart. (S. Clemens, A.K.A. Mark Twain) When in doubt hit the throttle. It may not help but it sure ends the suspense. (Gaz, r.moto) |
#52
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Initial fill (should have looked before I asked)
On Fri, 19 Dec 2003 19:29:13 GMT, Mark
wrote: I hope they also opened the bleed valve. huh? I have never seen a dip tube on an LP tank. I've only seen them filled with the tank on a scale. Dave |
#53
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Initial fill of new Propane tank fact or fiction on purge needed
"Mark" wrote snipped for brevity I don't know, Some of what's been posted is accurate but lots of this 'information' is inaccurate. And purging a gasoline tank? What a troll! Then theirs the motor fuel/ motor home people. They pull in and first question from me is anyone in the motor home. Working with LP wasn't bad, working with the people who use it was unacceptable. Mark Mark, very good post, thanks. You reminded me of a motor home fire I happened upon. It was at a busy shopping district just outside of Portland Oregon. The firemen had about a 1/4 mile radius marked off. The motor home was sitting along side a propane filling station behind a gas station. The firemen were hosing the motor home and the huge propane tank just along side of it. I managed to find a parking spot with a good sight line to watch. The motor home was a total loss, totally engulfed. Then all of the sudden kaboom! I thought that maybe the big propane tank went, but no it was still there. I figure the smaller tank in the motor home went. Wasn't much left of the motor home after that. I never heard if anyone got hurt. Very scary scene. Lane |
#54
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Initial fill (should have looked before I asked)
In article , David A Webb wrote:
On Fri, 19 Dec 2003 19:29:13 GMT, Mark wrote: I hope they also opened the bleed valve. huh? I have never seen a dip tube on an LP tank. I've only seen them filled with the tank on a scale. Dave yes, they used the bleed valve, too. the only time i see that left closed is on a large (80-100gal motor fuel) that is nearly empty. they open it past 1/2 way thru the fill, others open it before filling. years and years ago, some operators did not open the bleed until nearly full, no matter what type of tank. guess they didn't like to breath it. that was before all of the new laws. ymmv, --Loren |
#55
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Initial fill of new Propane tank fact or fiction on purge needed
"George E. Cawthon" wrote in message ...
You sure it was presssurized with a gas so that it didn't need to be purged? Stan Schaefer wrote: (Roy) wrote in message ... Just what is involved with filling a new propane tank. I just bought a brand new 100# tank. Took it to a gas supplier to get filled, and they want a $25.00 initial fee supposedly to purge it..........what gives. If its empty its empty. Its got the standard type of valve (OPD not required on a 100# cylinder) so it can be opened and any air inside can be vented to the atmosphere. Am I missing something here? Called two others and they also said the tank needs to be purged since its new.........I have bought new 20# and never had to have them purged . I smell a rip off for some reason. Maybe I just need to transfer some gas to give it a used smell into this new cylinder and then act like its been filled before. Visit my website: http://www.frugalmachinist.com Opinions expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy. I've bought several new propane tanks, they've all had to be purged. You DO NOT want air mixed with your propane in there. Purging amounted to opening up the bleed screw while propane pumping was going on, screw remained open until propane fogged out of the opening. The tanks were then filled to proper weight. I got to pay for the propane that escaped, there was no extra charge for the filling station guy having to use his screwdriver. You got ripped off. On two of the new tanks there was considerable air pressure in the tank before they were even hooked up. The last one I bled down before hauling it over to the rental place where I get tanks filled, took less time that way. It took about 15 minutes for the 60 lb tank to quit passing air after I opened up the screw, there must have been a lot of pressure in there. I suppose they use it for checking for leaks after assembly, probably roll them through a water tank after pressurizing and look for bubbles at the joints. At least being pressurized that way assured me that it wouldn't leak when filled. You need to find another, more honest, supplier. Stan Hey, I'm not sure what gas was in there, I just assumed it was air. Tanks are cheap, you think some manufacturer is going to go out of his way to put CO2, nitrogen or argon in there just to check for leaks? They can't be easily shipped with any flammable gas in there, either, lots of DOT regs on that. No matter, if it doesn't dissolve in propane liquid, you're still going to get excessive pressure build-up. Think what would happen if you took a closed tank full of pressurized air and started pumping in water. It's going to raise the pressure even more, right? Air will dissolve in water a little and I don't know the solubility of gaseous air in liquid propane(and have no real willingness to find out), so the cases may be a little different. You'd still end up getting more pressure in the tank than just what would be generated from vaporizing liquid propane at ambient temperature in the tank. Purging the tank the first time its filled is a pretty easy thing to do to avoid any possible problems. Stan |
#56
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Initial fill of new Propane tank fact or fiction on purge needed
In article , lane wrote:
"Mark" wrote snipped for brevity I don't know, Some of what's been posted is accurate but lots of this 'information' is inaccurate. And purging a gasoline tank? What a troll! Then theirs the motor fuel/ motor home people. They pull in and first question from me is anyone in the motor home. Working with LP wasn't bad, working with the people who use it was unacceptable. Mark Mark, very good post, thanks. You reminded me of a motor home fire I happened upon. It was at a busy shopping district just outside of Portland Oregon. The firemen had about a 1/4 mile radius marked off. The motor home was sitting along side a propane filling station behind a gas station. The firemen were hosing the motor home and the huge propane tank just along side of it. I managed to find a parking spot with a good sight line to watch. The motor home was a total loss, totally engulfed. Then all of the sudden kaboom! I thought that maybe the big propane tank went, but no it was still there. I figure the smaller tank in the motor home went. Wasn't much left of the motor home after that. I never heard if anyone got hurt. Very scary scene. Lane hmmm, i thought we decided they wouldn't blow up in a fire? maybe it got hot enough? maybe it was the hw heater, somehow? --Loren |
#57
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Initial fill of new Propane tank fact or fiction on purge needed
In article , Mark wrote:
Ken Davey wrote: On a lighter note; What is it about propane that triggers this group? I think I will call this phenomenon the 'King of the Hill' syndrome. I don't know, Some of what's been posted is accurate but lots of this 'information' is inaccurate. And purging a gasoline tank? What a troll! I don't miss working with propane. Not because it can be explosive or that it boils 44 degrees below 0, could be an interesting situation where your feet are being frozen solid while the rest of you is betting burnt to a crisp. .... There's the guy who wants me to put a little extra, AKA do an overfill, in his 20s because he's going hunting and doesn't want to run out. I tell him I can't do that, he says the other guy does it all the time. ?? the only situation that i asked for and received a "packed" fill was out on a freeway access road w/out of state plates on my propane powered 4x4. the guy asked how far it was going that day and would accomodate me, sometimes to 96%, depending on ambient temp. i did it because of price, usually cheaper out in farmlands, never would fill in the cities. it helps if your rig is newer, clean and towing. --Loren |
#58
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Initial fill (should have looked before I asked)
On Fri, 19 Dec 2003 21:34:43 GMT, Loren Coe
wrote: huh? I have never seen a dip tube on an LP tank. I've only seen them filled with the tank on a scale. Dave yes, they used the bleed valve, too. the only time i see that left closed is on a large (80-100gal motor fuel) that is nearly empty. they open it past 1/2 way thru the fill, others open it before filling. years and years ago, some operators did not open the bleed until nearly full, no matter what type of tank. guess they didn't like to breath it. that was before all of the new laws. ymmv, --Loren Please excuse my ignorance on this... I pulled the valves out of two 100lb LP tanks, and they looked like ordinary tank valves. No dip tube or anything. Does this have something to do with the new valve style? Dave |
#59
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Initial fill (should have looked before I asked)
"David A. Webb" wrote: On Wed, 17 Dec 2003 20:56:48 -0500, Jeff Wisnia wrote: 4. Pressurize the container to approximately 15 PSIG with LP-gas vapor. Never purge with liquid LP-gas; to do so will cause the moisture vapor to chill and remain in the container. 5. Fully open the container service valve and vent safely to the atmosphere. 6. Repeat the fourth and fifth steps for a total of five purgings. And exactly how is doing this making the tank safer than if it were filled without purging? As soon as the tank goes from zero pressure to 15psi the first time, the contents are no longer an explosion hazard. So why pressurize and vent? Is it simply to remove air because the air may contain moisture? Dave I don't know much about propane, but everything I have read says nothing about explosion hazard, maybe because air in the tank isn't one. If you have ever had a tank that has air in it, you can figure out that the main problem is that a bubble of air goes through and the burner quits. That means keeping an appliance going is a problem. That's bad enough, but some appliance (like outdoor barbecues, and many RV stoves, have no safety features, so after the bubble of air, propane follows and spills out, causing an explosion hazard. |
#60
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Initial fill of new Propane tank fact or fiction on purge needed
Richard J Kinch wrote: Jack Erbes writes: I think the bottom line on purging is to reduce the potential for explosions. If that's the case, then why do we use gasoline tanks full of air? Shouldn't they be purged, too? The "i think" answer was wrong, the question was wrong (or just sarcastic). Explain the explosion potential of air in a propane tank? And, there is no explosion potential in a gasoline tank, the air/fuel ration over the liquid gasoline is too rich to burn. Right at the filler opening is a different question. |
#61
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Initial fill of new Propane tank fact or fiction on purge needed
Richard J Kinch wrote: writes: Gasoline tanks are vented to atmosphere when they are filled - so they purge themselves. Obviously not, if they are open to the atmosphere. Exactly. As the fuel goes in, the air is displaced, "purging" the tank. A propane tank is NOT open to the atmosphere, so any air in the tank stays there. No, this is not purging. Even a "full" gasoline tank has some headspace containing a mix of fuel vapor and air. A near-empty automotive fuel tank will contain a large headspace with a potentially explosive fuel-air mix. I suggest you research that. |
#62
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Initial fill (should have looked before I asked)
In article , David A Webb wrote:
On Fri, 19 Dec 2003 21:34:43 GMT, Loren Coe wrote: huh? I have never seen a dip tube on an LP tank. I've only seen them filled with the tank on a scale. Dave yes, they used the bleed valve, too. the only time i see that left closed is on a large (80-100gal motor fuel) that is nearly empty. they open it past 1/2 way thru the fill, others open it before filling. years and years ago, some operators did not open the bleed until nearly full, no matter what type of tank. guess they didn't like to breath it. that was before all of the new laws. ymmv, --Loren Please excuse my ignorance on this... I pulled the valves out of two 100lb LP tanks, and they looked like ordinary tank valves. No dip tube or anything. Does this have something to do with the new valve style? Dave others here will have better knowledge, but no, nothing to do with the OPD. my experience is with motor fuel and bbq grills, over the past 30yrs, always, iirc, an 80% indicator/screw or valve. if part of the main fill/supply valve, there s/b a tube protruding down, maybe broken off? otherwise, on a 100gal motor fuel tank, the overflow is a smaller, dedicated valve with a tube attached. --Loren |
#63
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Initial fill of new Propane tank fact or fiction on purge needed
Stan Schaefer wrote: "George E. Cawthon" wrote in message ... You sure it was presssurized with a gas so that it didn't need to be purged? Stan Schaefer wrote: (Roy) wrote in message ... Just what is involved with filling a new propane tank. I just bought a brand new 100# tank. Took it to a gas supplier to get filled, and they want a $25.00 initial fee supposedly to purge it..........what gives. If its empty its empty. Its got the standard type of valve (OPD not required on a 100# cylinder) so it can be opened and any air inside can be vented to the atmosphere. Am I missing something here? Called two others and they also said the tank needs to be purged since its new.........I have bought new 20# and never had to have them purged . I smell a rip off for some reason. Maybe I just need to transfer some gas to give it a used smell into this new cylinder and then act like its been filled before. Visit my website: http://www.frugalmachinist.com Opinions expressed are those of my wifes, I had no input whatsoever. Remove "nospam" from email addy. I've bought several new propane tanks, they've all had to be purged. You DO NOT want air mixed with your propane in there. Purging amounted to opening up the bleed screw while propane pumping was going on, screw remained open until propane fogged out of the opening. The tanks were then filled to proper weight. I got to pay for the propane that escaped, there was no extra charge for the filling station guy having to use his screwdriver. You got ripped off. On two of the new tanks there was considerable air pressure in the tank before they were even hooked up. The last one I bled down before hauling it over to the rental place where I get tanks filled, took less time that way. It took about 15 minutes for the 60 lb tank to quit passing air after I opened up the screw, there must have been a lot of pressure in there. I suppose they use it for checking for leaks after assembly, probably roll them through a water tank after pressurizing and look for bubbles at the joints. At least being pressurized that way assured me that it wouldn't leak when filled. You need to find another, more honest, supplier. Stan Hey, I'm not sure what gas was in there, I just assumed it was air. Tanks are cheap, you think some manufacturer is going to go out of his way to put CO2, nitrogen or argon in there just to check for leaks? They can't be easily shipped with any flammable gas in there, either, lots of DOT regs on that. No matter, if it doesn't dissolve in propane liquid, you're still going to get excessive pressure build-up. Think what would happen if you took a closed tank full of pressurized air and started pumping in water. It's going to raise the pressure even more, right? Air will dissolve in water a little and I don't know the solubility of gaseous air in liquid propane(and have no real willingness to find out), so the cases may be a little different. You'd still end up getting more pressure in the tank than just what would be generated from vaporizing liquid propane at ambient temperature in the tank. Purging the tank the first time its filled is a pretty easy thing to do to avoid any possible problems. Stan We are all a little confused (us non-propane dealers). I've had three new tanks recently and none of them were purged the way it says on the tag. One of them gave me a little trouble that eventually went away. All of them cost me about $10 for a purge, nobody here does it for free. Most around here charge a minimum fee which is for filling a 20# tank. But, purging is for safety and reliability of the appliance usage. It has nothing to do with the possibility of the tank blowing up. Air in the tank when it is filled isn't going to increase the pressure over what it would be if filled without any air. After all, the valve is open to atmosphere pressure when filling. And when you use the tank, you use gas, not liquid, so the air comes out which is the problem. At least that's my take. |
#64
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Initial fill of new Propane tank fact or fiction on purge needed
Loren Coe wrote: In article , lane wrote: "Mark" wrote snipped for brevity I don't know, Some of what's been posted is accurate but lots of this 'information' is inaccurate. And purging a gasoline tank? What a troll! Then theirs the motor fuel/ motor home people. They pull in and first question from me is anyone in the motor home. Working with LP wasn't bad, working with the people who use it was unacceptable. Mark Mark, very good post, thanks. You reminded me of a motor home fire I happened upon. It was at a busy shopping district just outside of Portland Oregon. The firemen had about a 1/4 mile radius marked off. The motor home was sitting along side a propane filling station behind a gas station. The firemen were hosing the motor home and the huge propane tank just along side of it. I managed to find a parking spot with a good sight line to watch. The motor home was a total loss, totally engulfed. Then all of the sudden kaboom! I thought that maybe the big propane tank went, but no it was still there. I figure the smaller tank in the motor home went. Wasn't much left of the motor home after that. I never heard if anyone got hurt. Very scary scene. Lane hmmm, i thought we decided they wouldn't blow up in a fire? maybe it got hot enough? maybe it was the hw heater, somehow? --Loren Maybe it was anything -- aerosol can(s), can of peaches, case of pepsi, juggles the dog. That's the falacy of most cause/effect assumptions--no data. |
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Initial fill (should have looked before I asked)
"David A. Webb" wrote: On Fri, 19 Dec 2003 21:34:43 GMT, Loren Coe wrote: huh? I have never seen a dip tube on an LP tank. I've only seen them filled with the tank on a scale. Dave yes, they used the bleed valve, too. the only time i see that left closed is on a large (80-100gal motor fuel) that is nearly empty. they open it past 1/2 way thru the fill, others open it before filling. years and years ago, some operators did not open the bleed until nearly full, no matter what type of tank. guess they didn't like to breath it. that was before all of the new laws. ymmv, --Loren Please excuse my ignorance on this... I pulled the valves out of two 100lb LP tanks, and they looked like ordinary tank valves. No dip tube or anything. Does this have something to do with the new valve style? Dave The opd isn't required on all tanks. Maybe your tank is one of the exceptions. Is it horizontal, permanent mount, or what? |
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Initial fill of new Propane tank fact or fiction on purge needed
On Fri, 19 Dec 2003 23:45:04 GMT, Loren Coe
wrote: In article , lane wrote: "Mark" wrote snipped for brevity I don't know, Some of what's been posted is accurate but lots of this 'information' is inaccurate. And purging a gasoline tank? What a troll! Then theirs the motor fuel/ motor home people. They pull in and first question from me is anyone in the motor home. Working with LP wasn't bad, working with the people who use it was unacceptable. Mark Mark, very good post, thanks. You reminded me of a motor home fire I happened upon. It was at a busy shopping district just outside of Portland Oregon. The firemen had about a 1/4 mile radius marked off. The motor home was sitting along side a propane filling station behind a gas station. The firemen were hosing the motor home and the huge propane tank just along side of it. I managed to find a parking spot with a good sight line to watch. The motor home was a total loss, totally engulfed. Then all of the sudden kaboom! I thought that maybe the big propane tank went, but no it was still there. I figure the smaller tank in the motor home went. Wasn't much left of the motor home after that. I never heard if anyone got hurt. Very scary scene. Lane hmmm, i thought we decided they wouldn't blow up in a fire? maybe it got hot enough? maybe it was the hw heater, somehow? --Loren Or one of the tires. More likely than the propane tank. |
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Initial fill of new Propane tank fact or fiction on purge needed
On Sat, 20 Dec 2003 02:24:11 GMT, "George E. Cawthon"
wrote: We are all a little confused (us non-propane dealers). I've had three new tanks recently and none of them were purged the way it says on the tag. One of them gave me a little trouble that eventually went away. All of them cost me about $10 for a purge, nobody here does it for free. Most around here charge a minimum fee which is for filling a 20# tank. But, purging is for safety and reliability of the appliance usage. It has nothing to do with the possibility of the tank blowing up. Air in the tank when it is filled isn't going to increase the pressure over what it would be if filled without any air. After all, the valve is open to atmosphere pressure when filling. And when you use the tank, you use gas, not liquid, so the air comes out which is the problem. At least that's my take. Your take is wrong. Due to environmental issues, the tank is NOT vented to the atmosphere when filling by weight. The valve is connected to the filler hose, the valve opened, and the pump started. There is NOTHING in the tank but propane - either in liquid or vapour state. The tank is filled to 80% max capacity with liquid. The other 20% is pure pressurized propane. Now, if the tank is NOT purged, it starts out full of air at atmospheric pressure. It is compressed to 5 atmospheres pressure if below the boiling point of propane, and comprises a flammable mixture inside the tank at some temperature between there and normal ambient. Not likely a big safety issue - but there IS a point where an explosive mixture exists inside a non purged tank. When the tank is "used up" it does not have air in it if it started out purged - and would have VERY little even if not purged - assuming the valve did not freeze etc. So refilling the tank does NOT require venting. A "brown valve" on a vehicle tank also eliminates the requirement to vent the tank when filling. As soon as the liquid level reaches the bottom of the tube (80% mark) the fuel flow is shut off. Venting of propane tanks at fillup is currently illegal in many areas - as it should be - for both safety and environmental reasons. |
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Initial fill of new Propane tank fact or fiction on purge needed
George E. Cawthon writes:
Air in the tank when it is filled isn't going to increase the pressure over what it would be if filled without any air False. And when you use the tank, you use gas, not liquid, so the air comes out which is the problem. True, eventually. |
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Initial fill of new Propane tank fact or fiction on purge needed
The odor is strong, but it numbs your sense of smell. I had a summer
job working for the gas company where once in a while we would fill odorizers. When I got home my parents could smell the odor from my clothes, but I couldn't smell hardly anything for a day or so. Dan Jim Stewart wrote in message news:cPGdnY0RXeg3pX6iRVn- I've heard that the odor is so strong and so bad close up that it can cause people to become physically ill. Is this true? |
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Initial fill of new Propane tank fact or fiction on purge needed
Loren Coe wrote: In article , lane wrote: You reminded me of a motor home fire I happened upon. It was at a busy shopping district just outside of Portland Oregon. ... Then all of the sudden kaboom! I thought that maybe the big propane tank went, but no it was still there. I figure the smaller tank in the motor home went. hmmm, i thought we decided they wouldn't blow up in a fire? maybe it got hot enough? maybe it was the hw heater, somehow? --Loren Hard to believe but I'm pretty sure the tank in that motor home didn't much care what this group decides. -- -- Mark N.E. Ohio Never argue with a fool, a bystander can't tell you apart. (S. Clemens, A.K.A. Mark Twain) When in doubt hit the throttle. It may not help but it sure ends the suspense. (Gaz, r.moto) |
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Initial fill of new Propane tank fact or fiction on purge needed
Richard J Kinch wrote: George E. Cawthon writes: Air in the tank when it is filled isn't going to increase the pressure over what it would be if filled without any air False. Ok, so I exaggerated a bit since the total pressure is equal to the total of the partial pressures. If you took all the air in the tank at 1 atmosphere and compressed it into the space above the liquid nitrogen (compressed bout 5 times?) the psi would be pretty low and much lower than the propane gas. Since gas volume and pressure are inversely related and one atmosphere =14.7 psi, the pressure would be 5 x 14.7 or 73.9 psi. So just add that to the pressure of the propane which someone suggest was at least 200 psi. I don't think that has any significance for safety, unless they make awfully weak bottles. And when you use the tank, you use gas, not liquid, so the air comes out which is the problem. True, eventually. |
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Initial fill (should have looked before I asked)
On Fri, 19 Dec 2003 21:34:43 GMT, Loren Coe
wrote: In article , David A Webb wrote: On Fri, 19 Dec 2003 19:29:13 GMT, Mark wrote: I hope they also opened the bleed valve. huh? I have never seen a dip tube on an LP tank. I've only seen them filled with the tank on a scale. Dave yes, they used the bleed valve, too. the only time i see that left closed is on a large (80-100gal motor fuel) that is nearly empty. they open it past 1/2 way thru the fill, others open it before filling. years and years ago, some operators did not open the bleed until nearly full, no matter what type of tank. guess they didn't like to breath it. that was before all of the new laws. ymmv, --Loren Ive never seen anyone fill a tank with a scale before. I get mine filled and they simply pump in 4.5 gal with the bleeder open and call it good. Every place I frequent in So.Cal. does it this way. The older none OPD tanks would take a full 5 gallons done this way. I ran out of propane earlier this week in my RV as I forgot that I have a half gallon less now than before. Gunner " ..The world has gone crazy. Guess I'm showing my age... I think it dates from when we started looking at virtues as funny. It's embarrassing to speak of honor, integrity, bravery, patriotism, 'doing the right thing', charity, fairness. You have Seinfeld making cowardice an acceptable choice; our politicians changing positions of honor with every poll; we laugh at servicemen and patriotic fervor; we accept corruption in our police and bias in our judges; we kill our children, and wonder why they have no respect for Life. We deny children their childhood and innocence- and then we denigrate being a Man, as opposed to a 'person'. We *assume* that anyone with a weapon will use it against his fellowman- if only he has the chance. Nah; in our agitation to keep the State out of the church business, we've destroyed our value system and replaced it with *nothing*. Turns my stomach- " Chas , rec.knives |
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Initial fill (should have looked before I asked)
On Sat, 20 Dec 2003 02:29:50 GMT, "George E. Cawthon"
wrote: The opd isn't required on all tanks. Maybe your tank is one of the exceptions. Is it horizontal, permanent mount, or what? Not horizontal. Not permanent mount. Just a garden variety 100lb LP tank. Vertical, about 4 or 5 feet tall, a 12 to 18 inches or so in diameter, weighs about 40 pounds empty. (hard to judge, and I didn't see a tare weight stamped on it) The tanks are in a storage unit, now that they are cleaned and full of compressed air. The valves are still in the garage.... crap. No they ain't. I must have tossed them in the trash. Dave |
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Initial fill (should have looked before I asked)
I've gotten Propane and Butane and that hide the facts LPG
type of stuff for 40+ years. I used to have to get mine at a wholesale dealer - drive up the the pump stand - where the semi-trailer tankers get a drink themselves. There they used a scale. Read the weight off the side and went from there. They hated the tiny bottles but heck - propane was their lives. In the winter, when cold - they would just fill up to the overflow. So I think it was a matter of safety. A hot day might outgass the tank on the way home. Around here - always by the overflow - but then it is at a gas station... Propane by nature maintains a somewhat constant pressure within when not frozen. The gas expands and when the pressure builds up - it turns back into liquid. My brother-in-law used to work for Neptune and ? Gas Equipment - the folks that made the gas meters for propane. -- Martin Eastburn, Barbara Eastburn @ home at Lion's Lair with our computer NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder |
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Initial fill (should have looked before I asked)
On Sat, 20 Dec 2003 21:27:01 GMT, David A. Webb
wrote: On Sat, 20 Dec 2003 02:29:50 GMT, "George E. Cawthon" wrote: The opd isn't required on all tanks. Maybe your tank is one of the exceptions. Is it horizontal, permanent mount, or what? Not horizontal. Not permanent mount. Just a garden variety 100lb LP tank. Vertical, about 4 or 5 feet tall, a 12 to 18 inches or so in diameter, weighs about 40 pounds empty. (hard to judge, and I didn't see a tare weight stamped on it) OPD not required YET on 100lb cyls , up here anyway. 20 and under are definitely mandated. Not sure on the 50s. The tanks are in a storage unit, now that they are cleaned and full of compressed air. The valves are still in the garage.... crap. No they ain't. I must have tossed them in the trash. Dave |
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Initial fill (should have looked before I asked)
Those are 15 gallon tanks - I hate the tall unstable size. I'd rather
have a shorter fatter one myself. I plan on measuring my hoses before I get back to work - just in case I have to have new ones built - suspect I do. Martin -- Martin Eastburn, Barbara Eastburn @ home at Lion's Lair with our computer NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder |
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Initial fill of new Propane tank fact or fiction on purge needed
George E. Cawthon writes:
So just add that to the pressure of the propane which someone suggest was at least 200 psi No, more like 26 psi (0 deg F), 122 psi (70 deg F), or 190 psi (100 deg F). I suppose now someone will ask, "hey, can I use my propane tank to run my air tools without a compressor?" |
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Initial fill of new Propane tank fact or fiction on purge needed
In article ,
Richard J Kinch wrote: George E. Cawthon writes: So just add that to the pressure of the propane which someone suggest was at least 200 psi No, more like 26 psi (0 deg F), 122 psi (70 deg F), or 190 psi (100 deg F). I suppose now someone will ask, "hey, can I use my propane tank to run my air tools without a compressor?" Sure -- until the first spark. :-) A die grinder with front exhaust would be an interesting experience -- outdoors. :-) Something else -- indoors -- might be the last thing you do. Or -- a die grinder with rear exhaust would really call for Nomex work clothes. :-) Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
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Initial fill of new Propane tank fact or fiction on purge needed
Mark wrote in message .. .
Stan Schaefer wrote: I've bought several new propane tanks, they've all had to be purged. You DO NOT want air mixed with your propane in there. Purging amounted to opening up the bleed screw while propane pumping was going on, screw remained open until propane fogged out of the opening. The tanks were then filled to proper weight. Wrong. Very wrong. That was an improper purge, and if liquid was coming from the bleeder valve it was already near or at capacity. I said "fogged", not liquid. Low-temperature vapor, not liquid drops. I've done enough gravity filling to know the difference. They fill by weight, kind of hard to overfill if the scale is set correctly. Might be improperly done in your locale or by your standards, though. It DID get rid of the air or gas in there, the actual object of the exercise. The last one I bled down before hauling it over to the rental place where I get tanks filled, took less time that way. It took about 15 minutes for the 60 lb tank to quit passing air after I opened up the screw, there must have been a lot of pressure in there. I suppose they use it for checking for leaks after assembly, probably roll them through a water tank after pressurizing and look for bubbles at the joints. Nope. The tank had either dry air or N2 in it to prevent air and moisture from entering the tank which would cause rust and odorant fade. You really did yourself no favor by bleeding it off. Read my previous post on odorant fade, open the link and read the article if my words not good enough. -- Mark N.E. Ohio Well, it's between 6-10% humidity here in the summer, the air or gas is venting OUT, so just how is water vapor supposed to be going back in???? It was hauled over to the rental outfit for filling that day anyway. It was just curious to me that there was that much compressed gas in there already. One of the other posters figured partial pressure on the basis of the initial air or inert fill gas being at atmospheric pressure. It wasn't at atmospheric pressure, for as long as it bled it had to be at higher pressure than that. Can't be all that much higher, though, the DOT, or whatever their successors are, would start getting on them about shipping filled pressure cylinders. Next new cylinder I get, I'll stick a regulator with a pressure gauge on it just for curiosity's sake before I fill it. Stan |
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Initial fill of new Propane tank fact or fiction on purge needed
Stan Schaefer wrote: I said "fogged", not liquid. Low-temperature vapor, not liquid drops. I've done enough gravity filling to know the difference. They fill by weight, kind of hard to overfill if the scale is set correctly. Depends on the scale. Might be improperly done in your locale or by your standards, though. It DID get rid of the air or gas in there, the actual object of the exercise. I have written allot of stuff here trying to reduce your ignorance. However if you have read what I have posted and are of such little mental capacity as to not understand what has been written by me and in the links I have posted there is nothing more I can do to make you more aware. -- Mark N.E. Ohio Never argue with a fool, a bystander can't tell you apart. (S. Clemens, A.K.A. Mark Twain) When in doubt hit the throttle. It may not help but it sure ends the suspense. (Gaz, r.moto) |
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