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Does air loss happen while detaching the inflator ball head from tyre air valve stem

Discussion in 'Tyres & Alloys' started by renlouis, Aug 14, 2014.

  1. renlouis

    renlouis Amatore

    Messages:
    111
    Aleppey
    Grande Punto 1.3
    Friends, my question is not directly related to any vehicle but about the digital tyre inflating devices available at fuel stations. After inflation, the device shows tyre pressure same as the set pressure accompanied by a beep. And my question is after the beep, while removing the device's ball head off the tyre valve stem, does air leak from the tyre through the stem anyway?

    When I asked the guy filled the air, he said the air inside the device's tube escapes with a hissing sound and no air loss happens to the tyre while removing the ball head off the tyre valve stem. However I am not sure of this. So I usually inflate 2 PSI more than what is recommended by manufacturer.

    Please can you guys throw some light on this?

    The manual foot air pump with 2 cylinders I bought is a joke :lol (bulls**t)
  2. asimpleson

    asimpleson Esperto

    Messages:
    3,000
    Heptanesia
    Linea 1.3
    Yes momentarily there is, while removing from the pipe that fills and also I guess through the tyre valve till the valve closes again (though not significant for a good working valve). Inflating 2 PSI more or a PSI less is not good as manufacturers state PSI depending on recommended tyre size and vehicle weight. Not that it will hurt in the short run.
  3. renlouis

    renlouis Amatore

    Messages:
    111
    Aleppey
    Grande Punto 1.3
    Inflating 2 PSI more to compensate is because I doubt air escapes while valve being closed. So in my case, changed rims and tyres; valves are new. So inflating just 1 PSI more keeping this air loss in mind is okay, right?
  4. fiatlover

    fiatlover Esperto

    Messages:
    1,599
    Bangalore/Kasargod
    Bangalore
    Grande Punto 1.4
    I dont think this is a big issue to be worried about. The hissing sound is most because of the compressed air in the pipe escaping during disconnection.
    Adding an extra 2 PSI might end up getting the tyre over-inflated. 30-32 PSI may be sufficient. You many have t refill once in a month at the most, unless there is a puncture.
  5. asimpleson

    asimpleson Esperto

    Messages:
    3,000
    Heptanesia
    Linea 1.3
    Every time valve is opened closed air might escape unless maybe the screw type filler is used. :confused: It is difficult to quantify how much air gets released, but PSI is pressure and how much it drops on each count like filling or while checking is not known. So I guess a PSI more or less is tolerable tough optimum pressure is best to maintain at all times. That is why fuel stations have tyre filling compressors to remind customers each time to maintain right pressure for proper FE.
  6. asimpleson

    asimpleson Esperto

    Messages:
    3,000
    Heptanesia
    Linea 1.3
    Has anyone any experience or heard of these. Please share if it works as suggested.

    air alert.JPG
  7. renlouis

    renlouis Amatore

    Messages:
    111
    Aleppey
    Grande Punto 1.3
    Here is another one suitable for 195/60R15 tyre -
    4x Brass Car Tyre Pressure Monitors for 32 PSI Lock- Innovative Design - MOTOCOP
    http://www.ebay.in/itm/181531914026?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
    This may not be useful as it won't indicate if tyre is over inflated.

    I guess good to go for any efficient digital tyre pressure guage. Michelin has one available on eBay.uk -
    Michelin 12276 Keyring Digital tyre pressure Gauge
    http://www.ebay.co.uk/itm/Tyre-Pres...586?pt=LH_DefaultDomain_3&hash=item3c9d33a26a
    Please write here if you found this guage available in India.
    I'm planning to get one even though its slightly expensive. I'm waiting from other sources also about the accuracy of the guage. I think since we usually check pressure once in a month, the guage would be at least useful to check tyre pressure while changing the air pumps.
    Last edited: Sep 21, 2014
  8. renlouis

    renlouis Amatore

    Messages:
    111
    Aleppey
    Grande Punto 1.3
  9. renlouis

    renlouis Amatore

    Messages:
    111
    Aleppey
    Grande Punto 1.3
    Guys, I finally bought that Michelin digital pressure guage from Amazon; it cost me nearly 2600 including shipping charges and import duty. Amazon dispatched item through I-parcel, and DTDC delivered it to my address. Got the item within ten days after shipping from US.

    I have checked the readings while using the new digital guage and found against 2 inflators and verified accuracy. Frankly I am very much pleased with this piece of stuff -

    I have never used any guage to check pressure and no such experience. This one is pretty easy to use; shows tyre pressure within a second, seals amazingly fast with a beep. The only thing is that we need to press straight to the value stem reasonably fast (not too hard) and the rest is guaranteed. The important question in this post is about how much PSI of air lose in a press and release cycle. To my surprise it would be just about 0.033 PSI! which is quite nothing.

    IMG_20141012_130502.jpg

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