Forum Discussion

1L243's avatar
1L243
Explorer II
Nov 24, 2020

Propane Tank Vacuum Purge

I purchased new 30# tanks for my RV. They came shipped to the house with a sticker that says they have to be vacuum purged. This does not sound like something the local propane filler can do? Is it necessary and if it is what's the procedure?
  • rhagfo wrote:
    Old-Biscuit wrote:
    New propane cylinders are shipped either with 100# Air pressure OR under a vacuum

    Air Pressure........Cylinders need to be 'Vapor Purged' 4 times to remove all air

    Vacuum......propane vendor just fills them. NO Purging necessary


    Check that 'sticker' again.


    Why is some of this stuff so hard for people to understand??
    Thanks Old-Biscuit!


    Lack of Real Information, lack of comprehension, misunderstanding etc
    OR just plain stubborn
    New Cylinders shipped with air pressure NEED purging and it is not a gimmick as some would have you think.
  • dedmiston wrote:
    but the average propane monkeys

    Note that I differentiated between propane suppliers and "the average propane monkeys."

    Bobbo wrote:
    Note that a "propane supplier" is not the local UHaul guy or campground employee pumping propane.
  • 1L243 wrote:
    Ok, I rechecked the stickers. The sticker doesn't Vacuum Purge it says VACUUM PURGED!

    So, should I assume that the tanks have been purged already and are ready to fill?


    Yes, I would assume that they are ready to go.
  • Bobbo wrote:
    SDcampowneroperator wrote:
    Its a gimmick. Fuel to air ratios fall between the too rich and too lean for combustion, even then there has to be an ignition source in that critical % state in side the container.

    It has never happened. Purging is just a gimmick used by suppliers to charge you for something you do not need. Big tanks like 500 gallon tanks are shipped and filled with air at atmospheric pressure. They are not vacummed or purged. The negligable air and oxygen becomes too rich of a mixture to burn,

    Propane 101
    Ask your local firefighter.


    The potential water vapor could be a concern IF filled on 100% humidity day, IF used on much a colder day in which the tank empties to allow the water to boil. Otherwise, water will become and remain liquid until the pressure drops so low as to cause it to boil off or to freeze dry. That would be far below the boiling point of propane at -44.3 f Niether is ever likely or documented. It just cant happen

    Talk to your local firefighter. not your propane supplier Its akin to asking to a used car salesman vs a scientist One will tell you its safe , the other truth. both will tell you its safe
    Talk to your local fireman!

    Ever notice how people who have little or no knowledge of a subject are the most ardent in their opinions? I will take a propane supplier's word over a "firefighter's" word any day concerning propane. Note that a "propane supplier" is not the local UHaul guy or campground employee pumping propane.

    I have both firefghter training in 45 years of hazardous material training and propane supplier certification. Back that up with 24 years of pipeline welding on flammable gaslines and 19 years of filling propane in the camp we operated and sold this year. Call me and all the firefighters as uneducated ?
    You who discount the facts I write of need to go back to grade school and recall basic chemistry and the basics of air, water, fuel,
    Purging air out of a propane bottle is an unneccessary task. The very slight amount of oxygen is absorbed into the gas and enhances the fuel.
    Insome states, Oxygenation of gasoline is mandated!
    Massive pipelines are not purged.of air. Effort is made to evacuate water after hydrotesting the remaing water will evaporate into the fuel gas overtime with no harm to the end user.
    What benefit to purge a tiny cylinder other than to
    address the fears of the uneducated?
    Yes I do note that the uneducated with little knowledge and inexperienced are the first to be ardent I have science, experience, training, and all professionals in related fields to verify. naysayers have fear of that which they have not educated about.
  • SDcampowneroperator wrote:
    Bobbo wrote:
    SDcampowneroperator wrote:
    Its a gimmick. Fuel to air ratios fall between the too rich and too lean for combustion, even then there has to be an ignition source in that critical % state in side the container.

    It has never happened. Purging is just a gimmick used by suppliers to charge you for something you do not need. Big tanks like 500 gallon tanks are shipped and filled with air at atmospheric pressure. They are not vacummed or purged. The negligable air and oxygen becomes too rich of a mixture to burn,

    Propane 101
    Ask your local firefighter.


    The potential water vapor could be a concern IF filled on 100% humidity day, IF used on much a colder day in which the tank empties to allow the water to boil. Otherwise, water will become and remain liquid until the pressure drops so low as to cause it to boil off or to freeze dry. That would be far below the boiling point of propane at -44.3 f Niether is ever likely or documented. It just cant happen

    Talk to your local firefighter. not your propane supplier Its akin to asking to a used car salesman vs a scientist One will tell you its safe , the other truth. both will tell you its safe
    Talk to your local fireman!

    Ever notice how people who have little or no knowledge of a subject are the most ardent in their opinions? I will take a propane supplier's word over a "firefighter's" word any day concerning propane. Note that a "propane supplier" is not the local UHaul guy or campground employee pumping propane.

    I have both firefghter training in 45 years of hazardous material training and propane supplier certification. Back that up with 24 years of pipeline welding on flammable gaslines and 19 years of filling propane in the camp we operated and sold this year. Call me and all the firefighters as uneducated ?
    You who discount the facts I write of need to go back to grade school and recall basic chemistry and the basics of air, water, fuel,
    Purging air out of a propane bottle is an unneccessary task. The very slight amount of oxygen is absorbed into the gas and enhances the fuel.
    Insome states, Oxygenation of gasoline is mandated!
    Massive pipelines are not purged.of air. Effort is made to evacuate water after hydrotesting the remaing water will evaporate into the fuel gas overtime with no harm to the end user.
    What benefit to purge a tiny cylinder other than to
    address the fears of the uneducated?
    Yes I do note that the uneducated with little knowledge and inexperienced are the first to be ardent I have science, experience, training, and all professionals in related fields to verify. naysayers have fear of that which they have not educated about.


    Not sure where you got your propane training but you might want to consider a few facts:
    *New propane containers are hydrostatically tested for leaks before shipment (water)
    *Filled with air pressure for shipment... Air contains moisture and other contaminants
    *Any moisture present from the container to the inlet of the pressure regulator can cause the regulator to freeze up
    *moisture increases the possibility of rust forming inside
    *moisture causes the odor of mercaptan to fade to the point that it might not be noticeable

    Purging removes the air, moisture, and contaminants

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