SYSMAX Ind./Clike to find more about Nitecore flashlights!
Page 1 of 4 1234 LastLast
Results 1 to 30 of 100

Thread: Pressure Pot to Test DIVE LIGHTS!

  1. #1
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Pressure Pot to Test DIVE LIGHTS!

    At the request of one of our fellow CPF members here is a description of my pressure pot. Now, I did not build this. I had a machine shop do it and due to a misunderstanding I paid dearly for it. Works great though and has been indispensable in dive light building.

    The pot consists of an aluminum 80 tank that was decapitated with a band saw... It was then placed on a pretty huge lathe to face the end.


    Oh, the tank was an old condemmed tank! A flange was built with 20+ holes, even though I asked for 6 1/4"-20... I got a bunch of metric thread! Part of the misunderstanding along with the aluminum flange which I did not ask for since I was goingwith 1" plexy! A 1/4" hole was threaded for a PSI gauge and valve with wuick connect. PSI gauge was free so that's why it's so big.





    To use the pot:
    1a. Fill the pot with water as much as possible
    1b. Insert light or whatever to be tested
    2. Put the flange on with the gasket.
    3. Insert all bolts and tighten in a cross pattern until snug
    4. Close the air inlet valve
    5. Connect the compressor quick connect
    6. Open the compressor valve, if closed
    7. Slowly open the inlet valve to the pot
    Note- after the pressure reaches the desired pressure or the maximum psi your compressor is capable of, close the valve. You will notice a slight drop depending on air temp and water temp. Don;t freak out and think there is a leak! A leak will usually chew up about 10-20 psi depending on the size of the object being tested. Usually a drop of no more than 4 PSI is OK.
    Allow the object to sit in the pressurized pot for whatever time. I have gone from 2 hours to 2 days! Usually if it doesn't leak in 30minutes to 1 hour all is OK.
    8. Release air pressure slowly
    9. Remove cover and either be happy or extremely disappointed!!! If disappointed, take light apart, reassemble and repeat.

    This is probably the most stressful time in light building for me. After you have spent hours putting a light together, it could be destroyed in seconds!

    Some things I would have done differently:
    1. Smaller gauge mounted on the lid to allow for full filling of water without any shooting out when depressurizing. Although I barely ever fill it all the way since this thing can probably handle 500 psi... The weak point is probably the gasket.
    2. Mount the valve on the lid as well.

    Oh, and the white stuff you see in the tank is the result of leaving water in it for months. The aluminum corrodes a bit.
    Last edited by 350xfire; 08-26-2010 at 07:18 PM.

  2. #2

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Sweet! Do you test fully assembled lights, or just the empty hosts? I figure it's safer to just test the host....

  3. #3
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by wyager View Post
    Sweet! Do you test fully assembled lights, or just the empty hosts? I figure it's safer to just test the host....
    I do both depending on how comfortable I feel with what I'm working on! Thanks

  4. #4
    Flashaholic* Packhorse's Avatar
    Join Date
    Nov 2007
    Location
    New Zealand
    Posts
    1,902

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Cool pot.
    For mine I have a Mecjar which is a 11 litre aluminium beer keg ( the type of thing my grand dad would get filled at the pub before 6 pm closing and take home to drink).

    It has a 100mm lid that gets bolted down with 2 wing nuts.
    I use the garden hose to pressurise it and can hit 4 bar. Water pressure in town is 7 bar.

    I dont bother with a pressure gauge but can pop a dive computer in to it if needed.

    I never really do long tests since in my experience they tend to leak early.

    Now if I had a test pot like yours 350 I'd do some destructive testing!!!

  5. #5
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Yeah Pack, I'll have to try some destructive testing at hte dive shop as I don't have a compressor that can get high PSI. I figure 200-300 psi should tear something up!

    I always thought I could build one out of this:
    http://www.harborfreight.com/5-gallo...ank-66074.html

  6. #6
    Flashaholic* Packhorse's Avatar
    Join Date
    Nov 2007
    Location
    New Zealand
    Posts
    1,902

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    That would be a great pressure pot. Easy to access and cheap.

    Unless its destructive testing you dont need all that much pressure.

  7. #7

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    sweet, but it would be easy to plug the connection in the side and drill and tap the lid for a pipe connection. You could either buy a 1/4" pipe tap and 7/16 drill bit (as long as you have a drill motor that will hold it) or have your machine shop, or any plumber do it for probably a couple bucks.

  8. #8
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by divechief View Post
    sweet, but it would be easy to plug the connection in the side and drill and tap the lid for a pipe connection. You could either buy a 1/4" pipe tap and 7/16 drill bit (as long as you have a drill motor that will hold it) or have your machine shop, or any plumber do it for probably a couple bucks.
    Yeah, but it's already done so I live with it the way it is.

  9. #9
    Flashaholic* gav6280's Avatar
    Join Date
    May 2008
    Location
    10 Min from NDAC.
    Posts
    556

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Thanks, dude great article....

  10. #10
    Flashaholic* gav6280's Avatar
    Join Date
    May 2008
    Location
    10 Min from NDAC.
    Posts
    556

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Could you use a large pressure cooker??

  11. #11
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by gav6280 View Post
    Could you use a large pressure cooker??

    As long as it can hold the desired pressure why not? Plus, it will be full of water so if it blows, it will just splash water all over... Just make sure to fill almost full with water!

  12. #12
    Enlightened
    Join Date
    Jun 2008
    Location
    Raymore, Missouri
    Posts
    99

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by 350xfire View Post
    Yeah Pack, I'll have to try some destructive testing at hte dive shop as I don't have a compressor that can get high PSI. I figure 200-300 psi should tear something up!

    I always thought I could build one out of this:
    http://www.harborfreight.com/5-gallo...ank-66074.html
    Use a scuba cylinder as supply, with a fill whip and turn valve you will have all the pressure you ever need.

  13. #13
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Good point. I'll have to try that.

  14. #14
    Flashaholic* Klem's Avatar
    Join Date
    Mar 2010
    Location
    Perth Australia
    Posts
    581

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Mate that's a terrific project

    What pressure/depth do you take your torches to?

  15. #15
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Thanks. I got to the max my compressor goes to af 119 (265').. After the test usually drops a few PSI due to temperature.

  16. #16
    Flashaholic* gav6280's Avatar
    Join Date
    May 2008
    Location
    10 Min from NDAC.
    Posts
    556

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    I always thought that any pressure pot had to be absolutely full with water or it would basically just be a bomb waiting to happen??

    This thread has got me wondering how much pressure a home brew barrel would take???

  17. #17
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by gav6280 View Post
    I always thought that any pressure pot had to be absolutely full with water or it would basically just be a bomb waiting to happen??

    This thread has got me wondering how much pressure a home brew barrel would take???
    Doesn't have to be full... It's just good to have it full in case something happens and it blows. If it blows under pressure, the air will expand hundreds of times sending a shockwave out. Water does not compress therefore no shockwave. So better safe and fill it up.

  18. #18
    Flashaholic* DIWdiver's Avatar
    Join Date
    Jan 2010
    Location
    Connecticut, USA
    Posts
    1,519

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by gav6280 View Post
    I always thought that any pressure pot had to be absolutely full with water or it would basically just be a bomb waiting to happen??

    This thread has got me wondering how much pressure a home brew barrel would take???
    It doesn't have to be absolutely full of water. It's all relative. If you have a little air and it lets go, you get 'pop'. More air and you get 'bang'. All air and no water, "ka-boom!".

    Of course the pressure is important too. If a paint pot at 70 psi lets go, it's dangerous. If a scuba tank at 3000 psi lets go, it's deadly.

    I have a soda-fountain keg and a small beer keg, both say "max working pressure 130 psi". They are available on auction sites and at home-brew outlets, though I got mine at the local scrapyard. Keep in mind the doors are small and the connections are non-standard.

    D

  19. #19
    Flashaholic* DIWdiver's Avatar
    Join Date
    Jan 2010
    Location
    Connecticut, USA
    Posts
    1,519

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by Hallmcc View Post
    Use a scuba cylinder as supply, with a fill whip and turn valve you will have all the pressure you ever need.
    Please don't do that without a safety releif valve and a flow restrictor. One little twitch on the valve and you could blow something!

    I'd prefer using the inflator hose off the first stage. It's LP so much safer, but restricted to around 150 psi, whatever your IP is. I bought a cheap regulator at the home center, installed a BC inflator fitting on the input and a standard air-tool quick fitting on the output. That's how I run my pneumatic nailer when I don't want to drag around the compressor. You can shoot a lot of nails on a 30 cf pony tank!

    D

  20. #20
    Flashaholic kingofwylietx's Avatar
    Join Date
    Feb 2010
    Location
    DFW, TX
    Posts
    308

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by 350xfire View Post
    Some things I would have done differently:
    1. Smaller gauge mounted on the lid to allow for full filling of water without any shooting out when depressurizing. Although I barely ever fill it all the way since this thing can probably handle 500 psi... The weak point is probably the gasket.
    2. Mount the valve on the lid as well.
    To accomplish this, just put a plug in your existing fill port. Have the lid drilled & tapped. Install your valve & gauge in the lid.

    If you want to do that, let me know. I'll send you the smaller gauge & maybe a multiport valve if I have one that will fit the bill (we specialize in instrumentation & controls, so there are a lot of demo gauges, valves, & regulators lying around that I can dole out). PM me if you decide to do it.

  21. #21
    Flashaholic* Packhorse's Avatar
    Join Date
    Nov 2007
    Location
    New Zealand
    Posts
    1,902

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    I second the use of a reg and LP inflater.
    You can always adjust the IP up a little for more pressure.

  22. #22
    Enlightened
    Join Date
    Jun 2008
    Location
    Raymore, Missouri
    Posts
    99

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    I thought I would share mine, and yes it is regulated.
    Last edited by Hallmcc; 09-01-2010 at 01:49 PM.

  23. #23
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Nice!

  24. #24
    Flashaholic* gav6280's Avatar
    Join Date
    May 2008
    Location
    10 Min from NDAC.
    Posts
    556

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    This is nor fair! i want one.....

    Hallmcc - How does the lid stay on?

  25. #25
    Enlightened
    Join Date
    Jun 2008
    Location
    Raymore, Missouri
    Posts
    99

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by gav6280 View Post
    This is nor fair! i want one.....

    Hallmcc - How does the lid stay on?
    The t-handles and two lugs drop through a slot and turn. The pressure locks it in place.

    Last edited by Hallmcc; 09-01-2010 at 06:35 PM. Reason: added picture

  26. #26
    Flashaholic* DIWdiver's Avatar
    Join Date
    Jan 2010
    Location
    Connecticut, USA
    Posts
    1,519

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Did you DIY that? Looks like a professional/commercial build. Anyway, way nicer than mine. (looking for "green with envy" but couldn't find it).

    D

  27. #27
    Flashaholic* 350xfire's Avatar
    Join Date
    Aug 2008
    Location
    Texas
    Posts
    1,229

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Yeah, I like the latching system of your. On mine I have to tighten and loosen 6 bolts every time.... Not bad but gets tideous.

  28. #28
    Flashaholic kingofwylietx's Avatar
    Join Date
    Feb 2010
    Location
    DFW, TX
    Posts
    308

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    350xfire, if you are near Dallas, I have something you can try (if you change your port to the lid). It is a volume controller that will go up to 3000psi. No additional pressure generation is required (no compressors or compressed gases are needed). It works by displacing volume with a high and low pressure piston system. I think it would be fun to play with..

    Here is a link:
    http://www.ashcroft.com/products/tes...e-AVC-3000.cfm

  29. #29
    Flashaholic* DIWdiver's Avatar
    Join Date
    Jan 2010
    Location
    Connecticut, USA
    Posts
    1,519

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by kingofwylietx View Post
    350xfire, if you are near Dallas, I have something you can try (if you change your port to the lid). It is a volume controller that will go up to 3000psi. No additional pressure generation is required (no compressors or compressed gases are needed). It works by displacing volume with a high and low pressure piston system. I think it would be fun to play with..

    Here is a link:
    http://www.ashcroft.com/products/tes...e-AVC-3000.cfm
    Very nice. It's meant to be used dry, though, and I think it needs to be filled with water in order to get sufficient displacement to build pressure in the tank. I end up displacing a few cu inches of water getting my tank to 250 psi. Any idea how it would hold up wet?

  30. #30
    Enlightened
    Join Date
    Jun 2008
    Location
    Raymore, Missouri
    Posts
    99

    Default Re: Pressure Pot to Test DIVE LIGHTS!

    Quote Originally Posted by DIWdiver View Post
    Did you DIY that? Looks like a professional/commercial build. Anyway, way nicer than mine. (looking for "green with envy" but couldn't find it).

    D
    No, I did not build this one. I have built two since running into this one. I believe Global sells one that looks like it. I have a feeling that the original owner of the shop I run either knew the inventor or was involved with it. He seemed to know everybody and opened the place in 1959. there ae no stampings or tags on it, and the welds are all hand done. The commercial units sold today have a few changes but that could be just normal improvements.

    The Lid is really simple to make by the way.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •