Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Farmall & IHC Tractors Discussion Forum
:

LPG Question

Welcome Guest, Log in or Register
Author 
w6tractor

01-04-2005 15:18:40




Report to Moderator

What is the purpose of the vapor and excess flow valve on a propane tank? Specifically a 1953 Super M with factory LPG.

Thanks




[Log in to Reply]   [No Email]
NDS

01-05-2005 11:03:02




Report to Moderator
 Re: LPG Question in reply to w6tractor, 01-04-2005 15:18:40  
While I am wound up on this subject will offer a little unsolistited advice. Have seen several posts in past from people who intened to fill LP tractors from their home tanks. This will not work on typical home tank as they have vapor valve only. To refuel tractor you must have liguid valve that feeds from bottom of tank. It would not be big deal to pump tank dry and install valve but understand most LP dealers will not do this now for liability reasons. The large amount of vapor that must be bled is not only enviromental hazard but safety hazard. Have seen vapor drift over 100 feet to open flame and flash back blistering all exposed skin on person filling tractor and setting tractor on fire.

[Log in to Reply]  [No Email]
NDS

01-04-2005 17:27:48




Report to Moderator
 Re: LPG Question in reply to w6tractor, 01-04-2005 15:18:40  
Do not know if we are on same page or not but what we always called vapor valve was a valve to feed vapor to regulator instead of usual liquid. WE sometimes used this on cold weather start up to prevent regulator freeze up until hot coolant from engine was flowing through it. Tractor would not have nearly as much power running on vapor though. Excess flow valve is device in valve to shut off flow if it exceeds certain limit like if you have bursted line or regulator diaphram. This may not be what you are refering to but were terms used in cotton country in LPG hey day.

[Log in to Reply]  [No Email]
MT Pockets

01-04-2005 21:14:26




Report to Moderator
 Re: LPG Question in reply to NDS, 01-04-2005 17:27:48  
Hi W6Tractor. NDS is correct about everything he said. There is an excess flow valve on 4 valves on that tank. One each on Liquid withdrawal,vapor withdrawal,filler connection, and vapor return connection. They are made on to the male threaded parts of these valves and are on the inside of the tank where you can"t see them. The only valves that don"t have them are the 80% outage gauge and the pressure relief valve. The excess flow valve will stop 99.9% of the flow in the event of a ruptured line. They will also close if you open a valve too quickly to a line with little or no pressure in it. To reset the excess flow valve, simply close the valve. Momentarily, you will hear a click,as the gas bleeds through a tiny weep hole in the excess flow valve. The valve you are asking about is called the vapor return. It"s purpose is to return the vapor that is being displaced by Liquid during filling to the storage tank. That"s the answer to the question on the test. But in "cotton country" as NDS says, you put a fitting on there and "bleed" that vapor to the atmosphere in order to fill the tank. I hope this helps. Thanks, Steve Norwood, Texarkana,Texas.

[Log in to Reply]  [No Email]
w6tractor

01-04-2005 19:14:13




Report to Moderator
 Re: LPG Question in reply to NDS, 01-04-2005 17:27:48  
Thanks, but the valve I'm talking about looks like the fill valve, only smaller. It's on the tank at the far right in the same area as the fill valve and liquid and vapor supply valves.



[Log in to Reply]  [No Email]
NDS

01-05-2005 05:37:05




Report to Moderator
 Re: LPG Question in reply to w6tractor, 01-04-2005 19:14:13  
David is right on the vapor return line. Most farmers did not have pump but bled large amount of vapor out this fitting to lower pressure in tractor tank so higher pressure in storage tank would push fuel into tractor. Contrary to what most people think this was not like lowering air pressure but depended on large amount of vapor bl
ed to lower temperature of liqid LPG in tank causing pressure to fall. Sometimes tank would actually frost over. Vapor pressure of LPG varies greatly depending on temperature. Pressure will drop more than 50% with temperature drop from 100 to 32.

LPG is actually a liquid fuel when under pressure.

[Log in to Reply]  [No Email]
w6tractor

01-10-2005 16:50:34




Report to Moderator
 Re: LPG Question in reply to NDS, 01-05-2005 05:37:05  
Thanks to all of you who responded. Guessed it might be for venting or a return line but didn't know. Thanks again.



[Log in to Reply]  [No Email]
NDS

01-05-2005 05:32:46




Report to Moderator
 Re: LPG Question in reply to w6tractor, 01-04-2005 19:14:13  
David is right on the vapor return line. Most farmers did not have pump but bled large amount of vapor out this fitting to lower pressure in tractor tank so higher pressure in storage tank would push fuel into tractor. Contrary to what most people think this was not like lowering air pressure but depended on large amount of vapor bl
ed to lower temperature of liqid LPG in tank causing pressure to fall. Sometimes tank would actually frost over. Vapor pressure of LPG varies greatly depending on temperature. Pressure will more than double with temperature rise from 32 to 100.

LPG is actually a liquid fuel when under pressure.

[Log in to Reply]  [No Email]
David Manring

01-05-2005 04:06:27




Report to Moderator
 Re: LPG Question in reply to w6tractor, 01-04-2005 19:14:13  
that is where you hook up a vapor return hose when fillin it. Farm tanks didn't have that second hose, you just open the bleeder and quit when you see liquid.No good for the ozone they say.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy