[PSUBS-MAILIST] Pressure Test Chamber

Wed Jun 21 06:27:03 EDT 2017

Alan,I wondered about the oil under such pressure behind air  also but then thought of situations in real life where this happens.  A hydraulic system can very easily have an air pocket until it works itself out.  For instance when you change a cylinder it takes a bit of time to work the air out and it is under full pressure and in many cases higher than 3,000 psi.  My concern with what you described is the volume of air at the top of the chamber, but your your chamber is pretty darn bullet proof.  I use air to pressurize my chambers with water and figure the volume of air in the 36 inch long 1\4  dia hose is not going to amount to anything.  I always have a barrier between me and the chamber, but my chamber is home made.  I am not sure why you want all the mess with oil, can't you just drain it and wipe it down with WD-40.  It is a clever idea but I see a big mess to clean up. Hank 

    On Wednesday, June 21, 2017 2:40 AM, Beram Mahmoud via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

  Hello, well why not using the idea of hydroforming :
http://www.colinfurze.com/hydroforming.htmlUse a presssure washer with 200 bar and you got your 2900 psi...By doing so you have no issue with expanding gases. Best regards BeramGesendet: Mittwoch, 21. Juni 2017 um 09:40 Uhr
Von: "Stephen Fordyce via Personal_Submersibles" <personal_submersibles at psubs.org>
An: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
Betreff: Re: [PSUBS-MAILIST] Pressure Test ChamberHi Hugh & Alan,Good point to consider, but it would depend on the flashpoint of the oil.  SCUBA compressors do the exact combination of pressure/air/oil and don't explode.  Diesel engines do too - sort of, anyway.  Mineral oil designed for compressors would be a good option although pricey (AU$200 for 20L recently). Shell Corena P150 mineral oil is what I use. High pressure air is a mechanical hazard to be considered in and of itself.  I'd highly recommend installing a relief valve (or device) on any test chamber or other vessel. Cheers,Steve On Wed, Jun 21, 2017 at 2:28 PM, Hugh Fulton via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
Alan,Never pressurise oil with air to those pressures.  An explosion waiting to happen.  Oxygen partial pressures!!If you want to do it use nitrogen.Hugh From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of james cottrell via Personal_Submersibles
Sent: Wednesday, 21 June 2017 3:34 PM
To: Personal Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] Pressure Test Chamber Alan, Pressure testing that high needs to be done with liquid not gas. High pressure air is VERY dangerous. A pressure washer pump using water would be a safer choice. Greg From: Alan via Personal_Submersibles <personal_submersibles at psubs.org>
To: personal_submersibles at psubs.org
Sent: Tuesday, June 20, 2017 9:01 PM
Subject: [PSUBS-MAILIST] Pressure Test Chamber I am making a plastic container to fill with water & stand inside mypressure chamber. There is a gap between the wall of the container& the chamber which I intend to fill with oil. There will be about aninch of air at the top of the chamber & I'm using a scuba tank topressurise the unit up to 3000psi.Will car engine oil do to fill the gap between my plastic container &the chamber wall, or do I need to go with a hydraulic fluid.Am using the plastic container to keep water from rusting my testchamber. (Aussie Steve's idea)Cheers Alan Sent from my iPad_______________________________________________Personal_Submersibles mailing listPersonal_Submersibles at psubs.orghttp://www.psubs.org/mailman/listinfo.cgi/personal_submersibles  
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