Draeger-KISS CCR Dolphin

 

 

Generation One

This is the most important part of this page….using a device like this one CAN KILL YOU!!!!!

I take no responsibility for your abilities, construction skills, material selections, or your judgment of your own diving skills.  The only responsibility I take is for my own diving, I know that if I screw up, I will be DEAD, and no one to blame but myself.  If you are not disciplined enough to maintain your equipment, do a proper predive check, use checklists, tear down and reassemble your own Rebreather now, you have no business modifying it.  You should take a rebreather course from a nationally recognized training agency taught by an instructor who has the proper qualifications and plenty of time on the same unit, before using any rebreather.  Make sure your family knows the chance you take by building and modifying life support equipment, make sure your dive buddies know what to look for if you need help, and make sure your life insurance is fully paid up and you have the Divers Alert Network master or preferred plan.  The material presented here is for informational purposes only and not a construction plan for doing this yourself.  Dive Safe.

 

This is the first attempt at converting my Dolphin to a CCR.  The current unit (shown immediately below) is a bit different and much more streamlined and comfortable.  Continue on to the Gen 2 and Current Gen for how I got this far.  All of these units preformed the job of keeping me alive at depth extremely well, judging by the fact I’m still here.

 

  So here is the newest best CCR Dolphin ever.  I have one two pound weight attached to the shoulder straps on each side.  This and the backplate adaptor is all the weight I am using in the warm water with a three mil full wetsuit.

  The back side.  I painted my white shell black with the new Krylon Fusion paint made to bond to plastics, but it is getting beat up pretty fast.

 

So continue down and see how I got there, the below pics show the first step in the continued evolution.

          Looking at the rear of the unit, we see the diluent tank on the divers left side and the oxygen tank on the right. Fitted to the diluent tank regulator is a second stage with a long hose for bailout at depth, as well as an SPG for monitoring tank pressure and the inflator hose for the BC. The last low pressure hose from this reg connects to the demand port of the Drager dosage device. I had to cut and splice this hose taking a LP scuba hose and cutting the BC connector off the end and also cutting a Drager reg hose and splicing them together with a double ended barb and SS hose  clamps. I would like to find the correct adaptor to remove this splice, however I don’t ever expect this connection to fail as the pressure is minimal, about 150psi. If it did, in fact fail, loss of diluent supply would result but surfacing would not require any additional diluent and the loop would stay dry unless the diver sucked hard against a collapsed bag while descending.

          On the right side, the oxygen regulator has two hoses, one a HP hose going to an SPG to monitor 02 tank pressure, this gauge is conveniently cable tied to the KISS valve assembly you will see below. The second hose is a SS braided PTFE oxygen clean and compatible line that routes out to the KISS valve through a filter, again, see photos below. I have considered adding another second stage to this reg to allow OC access to 100% 02 for bailout decompression…still under consideration.

          The tanks have right and left hand valves installed on them that allow the regs to face inboard to protect the hoses and the valve to face forward to allow the diver to access them while wearing the unit. The tanks can be either 13cf, 19cf or 30cf depending on the divers needs, or you can mix and match if you don’t mind being asymmetrical. On this unit the diluent tank is 19cf and the 02 is 13cf both at 3000psior 200 bar for you metric folks. (multiply the cf capacity by 28 to get liters)

 

Here are two photos of my modified dosage device. Notice that all Drager orifices have been removed and the holes capped by hex plugs, this is not truly necessary but does clean up the profile. One of the hex plugs has been drilled out and tapped for npt thread. The adaptor from npt to A-loc fitting is threaded in there with Teflon tape to seal the threads.  This hose is fed oxygen from the KISS valve. The Drager demand valve is still completely functional but is fed from a standard scuba regulator instead of the Drager 1ststage through the spliced hose described above. The dosage device fits in the usual opening in the counterlung as seen below.

 

Here we see the dosage device in place at the counterlung (left) and the A-lock hose in place on the adaptor. Pictures seen looking at the front of the unit with the breathing loop at the top. I have covered the braided SS hose with convoluted plastic tubing to protect the counterlung from abrasion inside the unit. One of the drawbacks to these hoses and connectors is that they do not swivel and you must loosen them to rotate them. This is something I am going to address with the final tweaks.

 

This is my Oceanic reg with the environmental kit removed, the enviro kit consists of a plastic plunger, spacer and rubber cap. What this does in the reg normally is allow for the ambient pressure to act on the reg without water actually getting inside of it. Used mostly for cold water diving so reg is less likely to freeze up. However in this application, we don’t want the reg to adjust for ambient as the higher intermediate pressure will allow for higher 02 flow into the breathing bag through the KISS valve bringing our PPO2 up to dangerous levels. More about this in the How it works section.

This piece was machined out of PVC to fit perfectly in the cylinder bore of the regulator with an o-ring around the outer circumference. This blocks ambient pressure from affecting the intermediate pressure of the reg. The post at the top with the hole in it allows it to be hooked and removed for reg servicing. A bit of lube on the o-ring helps it to seat without extruding. This was one of the harder things to make correctly, I enlisted the help of an experienced machinist to help me.

 

These two shots show the blocker in place.

 

This is the rubber cap that is part of the environmental kit.

 

This is the end cap that threads on, holding all the parts in place and is part of the environmental kit.

 

The final assembly positioned correctly for diving. Lets move on now to the heart of the system.

 

  

 

Here we have the brains of the outfit, what brings it all together into a functional CCR. On the left we see the SS KISS valve, manufactured by Gordon Smith of KISS. What the valve does is allow a constant flow of Oxygen from the supply side to the breathing bag side, this flow is dependant upon the orifice size,(predetermined by the manufacturer) and the pressure on each side of the orifice. The supply pressure is maintained by the 02 reg at about 150psi, this will output about 1.1 liters of oxygen per minute. The average diver, under no work conditions, will metabolize about this much 02. You can find your own resting 02 usages by simply using your Rebreather while sitting in your living room and watching the oxygauge with the unit turned on, if the PP02 is climbing, turn down the IP of the reg, if it is falling slowly, you’re in the ballpark. The point is to have the system flow just slightly under what you need to survive at rest, never more. You can always add more 02 via the pushbutton on the KISS valve. Notice in the middle and R side pics on the end of the valve a slotted button. This is the02 add button, backed by a strong spring, it requires a determined effort to add 02, the button is flush with the end of the assembly to further guard against accidental activation. On the input side is a filter to guard against contaminants entering the valve and causing flow to stop or the add valve to stick open. Inline before the filter is a 90 degree ball valve to shut off 02 flow. You may also use the tank valve to control flow, but in the unlikely event of the 02 add valve sticking open I want a quick turnoff to avoid runaway pp02.

 

With the unit worn, the KISS valve and oxygen pressure gauge are in the divers right hand. Notice the bailout reg clipped to the right shoulder D ring. The seven foot hose is doubled up and secured with bands of bicycle inner tube to keep it out of the way but still ready for deployment. In the divers left hand is a console with SPG for the diluent tank, a depth gauge and compass. The depth gauge has been replaced with a Uwatec depth and bottom timer. Also attached to that assembly is the Drager Oxygauge with a cable and oxygen sensor running into the breathing bag. You must have two methods of monitoring the Partial Pressure of Oxygen in your breathing loop at all times, if the gauges don’t agree, end your dive. I have, on order, from Oxycheq a Hydrospace engineering Explorer http://www.hs-eng.com with a port for plugging in an oxygen sensor that will calculate in real time my oxygen otu’s, and decompression information.

 

   

 

 

Above we see left and right side views and the back view. I have the tanks mounted with SS Channel, and rubber edge trim with a standard cam band scuba strap. I am considering other mounting methods as the cam bands don’t like the smaller tanks. The diluent tank is mounted too low in the pictures and is higher now, so that the unit can sit on a boat seat without damaging the reg and hoses. I have mounted a light battery housing in the place of the original Drager tank. I am going to build a battery canister that is the same diameter of the Drager tank so the unit will sit up better also. (not shown)

 

          So, that is all for this section, please continue on to find out how the unit works, what testing has been done so far, where to I got my parts, my other links for cool dive stuff, and my section on the fill whips I build to mix your own gas.

          

        Remember, this is the most important part of this page….using a device like this one CANKILL YOU!!!!!

I take no responsibility for your abilities, construction skills, material selections, or your judgment of your own diving skills. The only responsibility I take is for my own diving, I know that if I screw up, I will be DEAD, and no one to blame but myself. If you are not disciplined enough to maintain your equipment, do a proper predive check, use checklists, tear down and reassemble your own rebreather now, you have no business modifying it. Make sure your family knows the chance you take by building and modifying life support equipment, make sure your dive buddies know what to look for if you need help, and make sure your life insurance is fully paid up and you have the Divers Alert Network master or preferred plan. The material presented here is for informational purposes only and not a construction plan for doing this yourself.

 

 

 

 

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