CO2 Gas Tank Valve State.

Discussion in 'The Projects Forum' started by kevin.khan, Jun 13, 2015.

  1. kevin.khan

    Thread Starter New Member

    Jul 9, 2012
    Hi there,

    I have a small project in mind and would like some direction as to how to accomplish the task at hand.

    At my work we have a CO2 gas tank that are used periodically. There is a valve attachment that connects to a flowmeter to ensure that gas is delivered at the right rate.

    The problem we are experiencing is that sometimes the gas tank is accidentally left open, resulting in a lost of gas, which can be quite costly.

    My idea is to develop a device that can be used to detect the state of the valve for the gas (i.e. determine whether the valve is opened or closed). Whenever the gas tank is open there would be an audio or visual prompt that would repeatedly alert the user until the valve is closed.

    Could you guys give me some ideas as to how I could achieve this task.
  2. #12


    Nov 30, 2010
    There is nothing to work with here. A tank of unknown size delivering an unknown amount per unknown time at an unknown pressure. No indication of any place where one might measure whether it was full of CO2 or Earth atmosphere, or whether that even happens. Should we try to measure the position of the knob on the unknown type of valve?
    Hypatia's Protege likes this.
  3. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
    At 'first blush' it seems you could place a pressure transducer (or, indeed, merely a pressure switch) immediately downstream of the valve such that any (metered) pressure whatever registers a 'valve open' condition... Note, however, that dependent upon system outflow 'rate' such a scheme may be annoyingly slow to indicate a 'valve closed' state...

    Best regards
    Last edited: Jun 14, 2015
    #12 likes this.
  4. DickCappels


    Aug 21, 2008
    Even simpler: hang a sign such as those on the door to some shops on the tank. One side says "open" and the other says "closed" and have the workers flip the sign to reflect the current state of the valve whenever the valve is opened or closed.
  5. #12


    Nov 30, 2010
    This illustrates the difficulty I am having. I don't know whether this CO2 flow is supposed to bubble through a liter of solution to produce carbonates or extinguish a restaurant fire. With no clue about the magnitude, I can't even guess whether the flow rate is enough to make the tubing cold.
  6. strantor

    AAC Fanatic!

    Oct 3, 2010
    Start deducting lost gas from payroll. The valve issue will sort itself out quickly.
  7. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
    Yep nothing to work with here. Everything is undefined For all I know your dealing 5 nines 5 grade CO2 or a fire suppression system. It could be a huge tank filled by a tanker truck or a small beverage C02 Tank. It could be a manual valve and a mechanical flow meter.

    Valve state indicators are common and so are electronic flow meters and you might be able to approach it from an entirely different angle. A CO2 sensor:
  8. Reloadron

    Well-Known Member

    Jan 15, 2015
    Like everyone else I haven't a clue because I can't picture what you actually have. That said I had a similar situation with Nitrogen bottles and valves. The valves had a handle which was round. I put a round plate on the handle with a lever microswitch. There are likely a dozen ways to determine if a valve is open or closed but one must first see the valve and situation. I can't see your valve and again no clue as to your situation and setup. Maybe place an optcal sensor on the flowmeter if it is a rotometer type design?