Chris Bryant
Arden, North Carolina
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Joined: 03/26/2003
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I’ll give yet another explanation. Electronic valves do not seal 100%, and they are all basically one way valves, offering no resistance backwards. LP gas is very temperature sensitive- the lp that remains in the lines at atmospheric pressure after they have leaked down will expand and contract with ambient temperature, it gets cold, and the pressure in the line is below atmospheric,,drawing in air to the system.
-- Chris Bryant
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dougrainer
Carrolton, Texas
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Chris Bryant wrote:I’ll give yet another explanation. Electronic valves do not seal 100%, and they are all basically one way valves, offering no resistance backwards. LP gas is very temperature sensitive- the lp that remains in the lines at atmospheric pressure after they have leaked down will expand and contract with ambient temperature, it gets cold, and the pressure in the line is below atmospheric,,drawing in air to the system.
Let me ask you this. The LP in the line is at pressure. It slowly leaks OUT due to pressure pushing it out. Does it not seem logical, that at some point after leaking down the in line pressure and the atmospheric pressure will be equal? The existing LP vapor left cannot exit OUT because there is no excess pressure to overcome the outside air. So, you reach a stand off. This is how I look at it. Doug
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red31
Dallas
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Time + thermal cycling w/leaks causes vacuum to suck in air.
the longer closed and not used yields more air.
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dougrainer
Carrolton, Texas
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red31 wrote:Time + thermal cycling w/leaks causes vacuum to suck in air.
the longer closed and not used yields more air.
Yes, but HOW MUCH VACUUM needs to be generated to PULL the outside air IN thru Rubber gaskets/seals? I doubt atmospheric Vacuum can pull air in thru a tight almost completely sealed system. Doug
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C Schomer
Pueblo West, Co.
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Micro leaks and thermo cycling makes the most sense to me but I have another explanation... sp!t happens! Craig
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RJsfishin
Winston Or.
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Joined: 10/16/2007
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I never have the problem, I just leave the propane on all the time.
When there is no leak, there is no reason to turn it off.
Rich
'01 31' Rexall Vision, Generac 5.5k, 1000 watt Honda, PD 9245 conv, 300 watts Solar, 150 watt inv, 2 Cos 6v batts, ammeters, led voltmeters all over the place, KD/sat, 2 Oly Cat heaters w/ ox, and towing a 2012 Liberty, Lowe bass boat, or a Kawi Mule.
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red31
Dallas
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dougrainer wrote:red31 wrote:Time + thermal cycling w/leaks causes vacuum to suck in air.
the longer closed and not used yields more air.
Yes, but HOW MUCH VACUUM needs to be generated to PULL the outside air IN thru Rubber gaskets/seals? I doubt atmospheric Vacuum can pull air in thru a tight almost completely sealed system. Doug
VERY LITTLE, I have no doubt (goes both ways). Open and close over short periods and there is little issue, close for weeks/months and the issue is there.
If 15.5 psia can leak to 15 psia then cooling and the pressure drops to ?? 14.5 psia or less?
The stick lighter flicker is my clue (long periods of closed) that it ain't propane causing the flicker.
* This post was
edited 03/13/20 06:24pm by red31 *
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dougrainer
Carrolton, Texas
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RJsfishin wrote:I never have the problem, I just leave the propane on all the time.
When there is no leak, there is no reason to turn it off.
Not a good idea if you are not using the RV. Doug
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deltabravo
Spokane, WA
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ford truck guy wrote:Normal.... been doing that for MANY years.... I used to start with the high output burner first, when I had 1. .
Ditto. All 6 RVs I've owned since 2003 have been like this. (or has it been 7 - I lost count)
2009 Silverado 3500HD Dually, D/A, CCLB 4x4 (bought new 8/30/09)
2009 Arctic Fox 811 (bought new 11/9/09)
2018 Timber Ridge 24RLS (bought pre-owned 3/12/20)
2008 Haulmark 8.5x20 toy box trailer
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time2roll
Southern California
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Joined: 03/21/2005
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Keep your nose tuned to the possibility of a leak near the regulator.
If the regulator is original in the two RVs in your signature it would be OK to just replace them.
2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up
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