Utility regulator

[pescador775]

This is a work in progress, an oxygen regulator with extended capability. When finished, it will be included in a kit of two regulators and accessories. The other regulator is an oxygen clean Conshelf to be used for in-water recompression. The regulator pictured (I'll try to furnish better pics later) is a Conshelf being converted for purposes of supplying oxygen to a free flow mask and demand regulator. It is equipped with a barbed outlet (default setting, 15 lpm) and quick disconnect to hook up the aforementioned Scuba demand regulator or various air tools. It has high and low pressure gauges and a relief valve. I drilled some test holes in another regulator body and decided not to drill and tap any ports but to use adapters. Parts and adapters are catch as catch can and I'll supply a list of parts and sources if anyone needs this.

I never liked fooling with medical oxygen equipment, the funky yokes and valves, the puny aluminum tanks, the bulky regulators or diminutive regulators with primitive, unbalanced valves. So, I decided to do something about it. When finished, one will be able to hook this reg up to steel tanks with real pressure and capacity. These tanks are fitted with old time backpacks and can be used in water or on deck. Everything will be properly labeled.

 

[james croft]

Looks good. I also think the O2 tanks are puny.
I had some aluminum cylinders that I cleaned for O2 use put in O2 valves. I believe they were SCBA cylinders and were 2216 psi .Some green paint and labels and I had a pretty good supply of O2 that would last a lot longer than an E cylinder.

 

[Luis H]

I like it. I may want to set up one in a similar set up.

Conshelf are also my favorite regulator first stage. I started O2 cleaning one for a deco regulator, but decided I didn't need full O2 clean just yet.

I did use the small orifice washer that Aqua Lung makes for O2 cleaned Conshelf and Titans, but I am not sure how useful it is. The washer does help identify an O2 dedicated regulator (it goes just below the snap ring and replaces the regular washer).

How are you controlling the constant flow supply (15 lpm)?

Are you using a submersible button gauge for the SPG?

Are you sealing the LP gauge?
Is the intention for the LP gauge to calibrate the regulator for a constant flow orifice?

What second stage are you planing on using?

I may O2 clean an AL 80 since I don't really use it for diving (I rather save my steel tanks for diving) and I would think that it may be easier to O2 clean an aluminum tank.

Thanks for sharing.

 

[oxyhacker]

We've had something similar for years, in the book, and on the website Gallery section as Cale's Swiss Army Knife - an old non-balanced piston (cheap, and easy to O2-clean) 1st stage with some NPT adaptors on the ports, pressure gauges to taste, and a flowmeter. It can be used as a sampler for analyzing, for emergency O2 administration, as a source of super-clean and dry air for blowing out gear (both dive and electronic) - and bubbling O2 (through a sintered element) into your homebrew beer wort. Especially handy if you have a serious medical problem far from shore, since it lets you run a medical mask from your deco bottles. Adaptors are easily made from hardware store brass fittings, as detailed in the OXY HACKER.

If one needs high output, for driving air tools or powering a portable booster etc, an old SP Mk5-style balanced piston 1st (with drilled-out fittings and ports as necessary) works better than an NBP or diaphragm 1st, as they are unmatched in their ability to flow high volumes of air. And cheap!

This is a work in progress, an oxygen regulator with extended capability. When finished, it will be included in a kit of two regulators and accessories. The other regulator is an oxygen clean Conshelf to be used for in-water recompression. The regulator pictured (I'll try to furnish better pics later) is a Conshelf being converted for purposes of supplying oxygen to a free flow mask and demand regulator. It is equipped with a barbed outlet (default setting, 15 lpm) and quick disconnect to hook up the aforementioned Scuba demand regulator or various air tools. It has high and low pressure gauges and a relief valve. I drilled some test holes in another regulator body and decided not to drill and tap any ports but to use adapters. Parts and adapters are catch as catch can and I'll supply a list of parts and sources if anyone needs this.

I never liked fooling with medical oxygen equipment, the funky yokes and valves, the puny aluminum tanks, the bulky regulators or diminutive regulators with primitive, unbalanced valves. So, I decided to do something about it. When finished, one will be able to hook this reg up to steel tanks with real pressure and capacity. These tanks are fitted with old time backpacks and can be used in water or on deck. Everything will be properly labeled.

 

[pescador775]

An air tool like 200 lb-ft impact wrench uses only 4 cfm. Certainly no problem for a Conshelf or Aquamaster first stage. I've run a small sandblaster and Haskel booster with an AquaMaster. Adjustable IP is a big help for general purposes. As a general observation, a regulator internal bore which is larger than the valve orifice does nothing useful. Now, to Luis' questions:

How are you controlling the constant flow supply (15 lpm)?

Are you using a submersible button gauge for the SPG?

Are you sealing the LP gauge?
Is the intention for the LP gauge to calibrate the regulator for a constant flow orifice?

What second stage are you planing on using?

The air flow is a function of pressure and orifice size. Regulator IP set to 100-110 psi and install a Western #77 orifice. A 1/4 npt to 3/8-24 available from Northeast Scuba.

Two separate regulator sets are used. The in-water set is a Conshelf coupled to an R109. Analog SPG and depth gauges.

The on board regulator is as pictured but the complete version will look a little different. The barbed orifice feeds a medical mask. The quick disconnect functions as a DISS port and feeds a 2nd stage regulator, a very light weight type. It is equipped with a 7 foot hose, head strap and nose clip.

Cleaning the Conshelf: dump the parts from the high pressure block and place in ENSOLV. Close ports and pour ENSOLV into the block. After one minute, drain the block and let a little run through the 7/16 port. Remove small parts from bath. Replace the O ring in the balance chamber with liberal O2 safe grease. Reassemble.

 

[pescador775]

If setting up the Conshelf as a utility regulator and a long hose run needs to be used, I suggest it be configured like an AquaMaster. Locate an oxygen orifice which is surplus to your needs (or buy an old regulator with orifice) and drill the fitting out with a 3/16 bit. It may be possible to avoid this step and buy a 1/4 inch oxygen (male thread) stud from a gas supply house. Attach the fitting to the regulator using the Northeast Scuba adapter. Suggest locktite for the regulator port connection.

North East Scuba Supply - Archives for: April 2008

Travel to a gas supply house and have a custom oxygen or inert gas hose made up with a 1/4 oxygen nut. On the other end of the hose, attach your favorite connector or QD with a hose clamp. The oxygen hose has a large internal bore and will handle anything that the regulator puts out.

 

[pescador775]

Luis, as this project started to move along I noticed a temptation to add all the bells and whistles.I had a lot of stuff lying around, unused, so I raided the junk box for gauges and fittings. When this thing is done it will be looking a little bit "spikey" but what the hey, it's fun. As you will discover, the Conshelf is just a wonderful platform for creative thinking. If one wanted to use a single first stage for everything, wet and dry, it might be better to simplify. One could just preset the Conshelf to a set pressure and omit the lp gauge. Also, this frees up an lp port for something else. The driver is the orifice and the need to supply adequate oxygen. This means that the default pressure should be about 110 psi. Use a pony bottle gauge for HP and omit the low pressure gauge; or, hook up an SPG to a quick disconnect. When the oxygen orifice is not in use, remove the barb and install a 1/4 oxygen nut(I use an Aquamaster nut). Install a QD on the lp side if you like but make sure it is a high flow type so as not to starve your air tools. Diverite sells a bunch of expensive but very cool fittings. See Northeast Scuba for the relief valve, $15.

SCUBA Hoses and Adapters..Variety of Lengths, Colors, Fittings

There are many options and altenatives to get where you want to go. However, building a regulator which is saltwater compatible and will also do surface duty should not be difficult.

 

[pescador775]

After all the work is done, and the thing looks beautiful, remember that it actually has to perform a job. A diver in extremus needs effective treatment and this usually means head tilted down and pure O2 up the nose. The Hacker book mentions that the disposable oxygen mask has a single exhaust valve and a naked valve port which serves as an air vent. Tape over the vent but monitor the diver to determine if the flow is enough. If not, adjust the regulator knowing that your rig will really deliver beyond that of an ordinary O2 medical set. This means your kit should contain a small tool like an L shaped piece of 5/8 inch sheet metal to turn the IP adjustment screw on the Conshelf. If the regulator is also used in salt water the adjustment screw must be removed and greased, then reset to 110 psi.

 

[pescador775]

The Western #77 orifice is available from Airgas for $11.50 but I've found that complete regulators can be purchased from our internet flea market for $6.50. What one should look for are the old style, shiny chrome, regulators from Western, Hudson, and Puritan. There are others but these are the usual suspects which would have that part. Since the orifice is 1/4 inch npt the adapter from Northeast Scuba is needed. Unscrew the #77 orifice from the oxygen regulator and adapt it to a lp port on your Conshelf.

Speaking of adapters, here are a few tips:
Buy gauges with 1/8 npt. Adapt to the 7/16 regulator port with a part from McMaster Carr. This is 50715K171. This is known as a "flared tube fitting adapter for 1/4 tube X 1/8 npt female". Grind about 1/8 inch from the tapered nose and slip on an O ring. You are good to go.

I haven't found a stainless fitting to fit a 1/8 npt gauge to the 3/8 regulator port. However, this will work alright for surface duty. Speedway sells an adapter called "GAUGE FITTING, STRAIGHT AN3 MALE, 1/8" NPT". FEMALE ". Same comment as before, grind a little bit off of the nose and slip on an O ring. McMaster sells the stainless fitting for the HP port but it is unclear what their lineup offers in smaller sizes like 3/8-24 (AN-3) which fits the lp port. Their line up jumps from 1/4 tube (AN-4) to 1/8 tube (AN-2) which is very strange. However, the AN-3 is a common size used in brake fittings so speed shops will sell these things all day long.

 

[pescador775]

The plan is to connect the SCUBA 2nd stg with 7 foot hose to the regulator using a quick disconnect. The QD that is on order is a mini type with check valve, a tubular design which does not restrict flow. The price is right and the specs look good. To make this work the QD plug (phone jack thing) must screw into the SCUBA hose. This requires an adapter which is SAE 3/8 O ring female to 1/8 npt male. I ordered two of these from Chassis Shop at a hefty price of $7 apiece. I took delivery and discovered that the adapters were in fact 3/8 inverted flare female to 1/8 npt male which normally sell for a buck each at a hardware store or hydraulics shop. Jeez.

Hacker to the rescue. Vance's book mentions a quick fix which involves drilling the lip of the female side to create an O ring shelf. He gives the specs for the drill size, use a lathe, and all that good stuff. Heck, it's only 110 psi; I just inserted a 1/2 inch, 60 deg counter bore in a hand drill and buzzed the lip until it looked OK. After that, to improve flow and reduce the internal nipple, I drilled it out with a 3/16 bit. Total work time, 5 minutes. Live and learn.