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  • 21-04-2010 7:46pm
    Registered Users Posts: 123 ✭✭

    HI ALL

    I am trying to work out what is the formula to work out the litres of oil in my tank . Now I know what is the normal formula for VOLUME calculation but as these tanks arent normal rectangular and have the re enforced joints etc they are hard to calculate .

    When i dip the stick i measure it in cm

    Oh Ye its a Platinum Tank (green) 1150 liters.

    Before I call the manufacturers I was hoping that somebody might know on the forum .

    Thanx in advance


  • Registered Users Posts: 1,255 ✭✭✭.243

    on the standard rectangular steel tank its roughly 6 gallons per inch,so it will be reasonably close to that with a rect plastic tank

  • Registered Users Posts: 123 ✭✭para45

    Thats good thanx. Gives me a idea of how much I have now. As soon as I hear from the manufacturer I will post that also and compare .

    Your formula sounds spot onn

  • Registered Users Posts: 7,516 ✭✭✭Outkast_IRE

    could you just use the cylinder volume calculation and knock off a percentage for the reinforced areas.

  • Registered Users Posts: 123 ✭✭para45

    HI Outcast.

    No I dont think so becuase I dont know how thick those reinforcements are and also the seams are also on the underside of the tank so not sure how deep they are. Its the kind of thing that the person that made it can tell you as they will have the spec. I know because the tank I replaced this one with ( A year ago ) was the same make but had a crack and when disposing of it I cut it up in to small peices to transport . ANd the joint/reinforcements are massively thick

    I have called them varouis times now and left messages but no reply back.

  • Registered Users Posts: 816 ✭✭✭Satts

    The way I do it is meausre to almost the full hight of the tank, I stop just before it starts to slope up, the last 2 to 3 inches to allow for expansion, so I would then call my tank 1100 litre instead of 1150 litre. Most of the delivery guys leave this expansion gap anyway.

    Lets say for example I measure this height and it is 4 feet high(122cm) = 100% capacity.

    So 122cm / 100 = 1.22cm = 1% capacity.

    I don't dip the tank, too messy.
    I look into the tank with a flash lamp. I'm lucky with my tank, because there are ridges every couple of inches.
    When I am happy I know which ridge the oil is near, I go back to the outside of the tank and measure from the bottom of the tank to this ridge.

    So for example I measure to this ridge and it is 44cm.

    So 44cm / 1.22cm = 36% of capacity.

    So 1100 / 100 x 36 = 396 litres of oil left in the tank.
    When I was looking in I probably would have estimated it at one third full anyway.
    If I want to fill the tank again I need to order 64% of capacity, which is :

    1100 / 100 x 64 = 704 litres of oil to be ordered to almost fill tank.

    So when I'm haggeling on the phone on prices I could be pretty confident
    in saying I need 700 litres, instead of them coming out and I need only 400 or 500 and them wanting to charge a higher rate per litre for the smaller load.

    I don't worry about the ridges and supports.
    If the ridges are uniform from the top of the tank to the bottom, it really dosen't matter. Full height = 100% capacity, half the height of the tank = half the capacity = 50% etc.
    e.g. Half the height = 61cm / 1.22cm = 50 % capacity.

    This works for me every time.

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  • Registered Users Posts: 123 ✭✭para45

    Satts. YOu are the man/woman . Thanx for all of that its much appreciated .