Pressure Test of Vessel - Home Visit

  1. WvW Member

    Messages:
    29
    Location:
    Derby
    Hi,
    I purchased a second hand air vessel to stick in my shed a year back. It had, to my knowledge, been tested/checked yearly, although the last sticker on it was 2016, up to the point I bought it.

    It looks in good condition, and there was no water in when I got it, however I have bottled it and am now concerned about whether it will give way (I'm 99.9% sure it will be absolutely fine, but it's not the kind of thing you want to get wrong).

    I wondered if there was any way of getting it checked out properly? I am unable to move it because of its size, so I had looked to see if there are any companies which don't mind coming to your house to do a check? Does anybody have any experience of any?

    I haven't opened the inspection port on it yet....
     
  2. winchman

    winchman Member

    Messages:
    3,775
    Location:
    Merseyside
    Its a very simple task. Is it for personal or business use?
    Open it up, clean it out, close it fill with water and pump up to required test pressure, should be marked on vessel leave for 15 mins to 1 hr.
    If a proper insurance man did it he would also do a thickness test they know the failure points so know which bit to look at.
    Use one of these
    https://vevor.co.uk/products/hydrau...XwJt2f_uT-ZTXASjq2y_rbBafaZBfMWsaAia3EALw_wcB
     
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  3. Agroshield Member

    Messages:
    1,389
    A pressure test using air is quite risky. A lot of tests are done hydraulically (i.e. using water). Then if something does blow, you just get a bit wet and not a bit dead.

    It would be good to give it a proper visual inspection before any pressure test anyway. Endoscope cameras with built-in lighting are very cheap and are ideal for the job. If you see any area of the tank that is less than perfect, ultrasonic thickness testers are again very cheap.

    For a compressor tank, which will likely use standard BSP fittings, a pipework test bucket (look up Rothenberger RP30) might be your most economic option.

    Does the sticker tell you the pressure to which it was tested? If not, a bit of Google will tell you what factor of working pressure is appropriate (I have the number 2 in my mind, but check this out yourself).
     
    Parm likes this.
  4. Munkul

    Munkul Jack of some trades, Master of none

    Messages:
    3,157
    Location:
    Cumbria
    Open inspection port, check for rust. If it's spotless, then crack on!

    If its not, then clean it with something until you can assess the corrosion more thoroughly.

    150psi isn't a great pressure in the big scheme of things, it's incredibly unlikely to catastrophically fail unless it has a whole load of corrosion, or a specific fault line. The base is the most susceptible, carrying water.

    If its for work, you should have a written scheme of inspection from a competent body, if it's over 250 bar-litres (at 10 bar rated pressure, that's anything over 25 litres capacity)
    Not sure how many garages actually have a WSE for their compressor receivers, though, in my experience barely any. Unless they're a really big outfit.
     
    Brad93 likes this.
  5. WvW Member

    Messages:
    29
    Location:
    Derby
    Ok. So this is for personal use. The vessel does have its data plate, so I know the test pressures etc.

    First job then is to open it up and have a look. I will post pictures up with what I find. If it looks ropey, then I will look to doing the hydraulic check.
     
  6. Cuthy246

    Cuthy246 Member

    Messages:
    438
    Location:
    Scotland, Highlands
  7. James1979 Forum Supporter

    Messages:
    1,606
    Location:
    Orkney
    I had a company called Vulcan Inspection Services do mine. No idea what they cost as insurers paid for it - they insist on inspection. He ran it up, put various gauges into the outlets and measured the drop over time.

    Drain port off then inspection camera inside which he videoed.

    it took less than an hour but he hung it out for 2 as that’s what his governing body say it’s supposed to take. A lot of it was smoke and mirrors to be honest.

    best thing I’d suggest in addition to the good advice above is an inspection camera inside if you can borrow one
     
  8. Morrisman

    Morrisman Forum Supporter

    Messages:
    2,720
    Location:
    Staffordshire, England
    That doesn't sound like he actually 'pressure tested' it. Pressure test takes it to 50% over working pressure, for a minimum period, depending on what the legal parameters are for the situation.

    We used to do the big 2000psi air systems on the old survey ships I worked on, had to fill the whole system with water then pump it up to 3000psi for 30 minutes, with no more than a 1% drop.
     
  9. James1979 Forum Supporter

    Messages:
    1,606
    Location:
    Orkney
    Probably explains why he is given 2 hours in which to do it!!

    It did seem a bit pointless to be honest.

    sounds like the OP would do better to follow some advice on here and have a go himself
     
  10. WvW Member

    Messages:
    29
    Location:
    Derby
    Agreed. I have an inspection camera (Lidl special) but it doesn't record. I will try and take some photos on my phone and post them up for people's opinions.
     
  11. anto44

    anto44 Member

    Messages:
    1,419
    Location:
    ireland
    Every garage I worked in would have yearly inspections of all equipment. I never seen one being pressure tested, it was always just a visual inspection followed by a borescope inside to check for corrosion. I got chatting to the guy doing it one time and he told me that they never pressure test them, if they find anything they're not happy with on the inspection then they tell the garage to get the compressor inspected and recertified by the manufacturer.
     
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  12. julianf

    julianf Member

    Messages:
    5,063
    Location:
    devon, uk
    Place where I used to get mots done bought a new compressor every year (or maybe it was two) as they said the testing fee cost more than a new compressor...
     
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  13. James1979 Forum Supporter

    Messages:
    1,606
    Location:
    Orkney
    I can believe that. I know a guy who does the same with ramps. Rather than loler them it’s cheaper to buy a Chinese one with cert then sell it every year and buy another.
     
  14. Morrisman

    Morrisman Forum Supporter

    Messages:
    2,720
    Location:
    Staffordshire, England
    Same with chain hoists, lifting slings etc offshore, some nob in safety management decided we would have them all sent shoreside to be sent off for inspection.....

    We just ordered new ones every two years and scrapped the old ones. $100 for a brand new 2 ton chain hoist, it was barely more expensive than the inspection anyway.
     
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  15. James1979 Forum Supporter

    Messages:
    1,606
    Location:
    Orkney
    Sounds familiar. No different when I was at sea. The other way seemed to be test absolutely nothing and hide under the flag!
     
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  16. brightspark

    brightspark Member

    Messages:
    31,750
    Location:
    yarm stockton on tees
    if your so concerned turn it over and tap along the bottom with a ball pein hammer. if it dents its on the way out if it doesn't its fine even if it did leak it would only be a rust pinhole
     
  17. WvW Member

    Messages:
    29
    Location:
    Derby
    Some pictures - first issue is removing the plug. What's the normal procedure here? Stillsons? Or is there a special tool here? Either way, I don't own either (yet).... IMG_20201117_155845.jpg IMG_20201117_155852.jpg
     
  18. brightspark

    brightspark Member

    Messages:
    31,750
    Location:
    yarm stockton on tees
    looks like someone's already had a go at it. if it wont loosen with stillys heat it up 1st and try again
     
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  19. WvW Member

    Messages:
    29
    Location:
    Derby
    Ok - Hopefully 24" will shift it. If not I will give it a dose of heat.
     
    brightspark likes this.
  20. awemawson Forum Supporter


    But if it's of recent Chinese manufacture (which it isn't from the pictures) it'll probably dent with a hammer anyway and any place, so just use your thumb!
     
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