KISS Rebreather tear down




Here are some pictures of Gordon Smithís KISS Rebreather being taken apart and reassembled by him aboard the Nautilus Explorer in March 2003.

The commentary is by me, hopefully all accurate.

The is the main section of the KISS, the top of the unit is to the left and Gordon has his hands on the head of the unit.The SS hose clamps hold the Oxygen and Diluent tanks in place. On the right side of the pic on the bottom, notice the hole, this is where the regulator fits.The frame is aluminum and has a coating, seems very tough and corrosion resistant, the counter lungs fit in the space above the regulators, one on each side.There is a Velcro and fabric strap that holds the CL at the bottom and keeps it from floating up in its space. He has various sizes available for the counter lungs, 2,4, or 6 Litre sizes.The counter lungs are MSR water bottles from camping suppliers.


The Head is mounted to the frame by 2 screws, and is being removed in this pic.The cable coming from the head is from the 3 sensors. Wrapped by plastic loom to keep them together, they are individually run from each sensor to each display, completely redundant and no single failure point, more on the sensor display system later.

The black disc is the protective cap for the head, it covers the gas ports and the sensor array. Notice the PP02 display with the wrist straps, you can also clip this to a d-ring.The sensor array unmounts with 6 screws and pulls off of the head for access to the sensors.


Removing the sensor cap reveals the wiring and tops of the sensors, I believe that Gordon uses Teledyne R22D sensors from Oxycheq.The top of the head also has an exhaust valve mounted into it, to relieve pressure in the breathing loop while ascending.This prevents the loop from over expanding if the DSV is off on a bailout ascent.The SS lines are for the KISS valve.


The 45 deg fitting is the diluent fitting, It is feeding a tilt valve that adds diluent when you inhale against an empty counterlung, the 90deg fitting by Gordonís left thumb is the 02 add port, notice in the background the MSR bottle counterlung.



Breathing hoses, sensor wiring, DSV, KISS valve lines, and cap.




The head of the unit.The larger ports at the bottom and right are the Counterlung attachments, the water bottle mouth slips over the fitting with the holes drilled around the circumference and is held in place by the threaded cap that spins on.The three threaded ports above the CL ports are for the breathing hoses and the center one is for the exhaust OP valve, similar to a drysuit exhaust valve.The two holes between the CL ports are the mounting holes.This piece is made of Delrin and is quite robust and has some marvelous machine work on it.The happy eyes behind the head is Curtis Nelson.



A better shot of the dil add port, top left and the 02 add fitting bottom right.If you kill yourself on this you cant say you werenít warned.


The DSV (dive surface valve) is a work of art and science, I saw the internal working parts of this and although I donít have pics, trust me, it is very cool.This unit works like a normal RB mouthpiece, with the knob turned in line with the RB hoses, one way valves keep the breathing gasses moving in the right direction.When you turn the knob in the position show it internally isolates the loop and seals it and simultaneously allows the diver to take a breath from the scuba regulator attached to the DSV, very slick and easy to use.He has also made an option for the DSV that allows you to add diluent or 02 with a little button you move with your tongue, this requires removal of the scuba bailout reg but makes for hands free diving.That option seems to be quite popular.This unit is made from Delrin also.It is sized for normal scuba mouthpieces.


Frame, notice the reg at the bottom right peeking through its opening.This is the diluent reg.


PP02 sensor displays.Each display is individually housed, has its own battery ( I forget the battery life, something like 20 hours with the backlighting on, much more with it off)The backlighting is turned on with a jumper internally, not easy to get to, so you should decide to either have it always on or off because you have to open the case to change it.To turn on the displays you slide a tiny cylindrical magnet in a groove to one side which activates a reed switch internally.Each sensor has its own cable, and sensor to read.If one fails, floods, or farts, it doesnít affect the other two.


The back of each unit has a plug that can be unscrewed to reveal a calibration potentiometer. The port is a standard scuba 1st stage LP hose plug.See the magnets in their grooves.


The head being reattached, notice the diluent accessory manifold near the top left of the pic.This is fed from the Diluent reg and distributes gas to the RB demand valve, the BC inflator, and DSV bailout reg.


(Pic is of my valve, I didnít get a good pic Gordonís during the tear down.)

This is a picture of Gordonís KISS valve which is the heart of his RB.It provides a constant flow of 02 into the breathing bag, adjusted to the individual divers metabolic rate.It also incorporates an add valve, the slotted button on the end, to manually inject 02.For a better description of how the system works read my section on ďhow it worksĒ as oxygen injection system of Gordonís RB is the same as mine.I used his valve to convert my Drager into a CCR.


Scrubber parts from left to right.Top screen, bottom screen with flow tube attached,bottom cap and canister.


Scrubber top.The scrubber is a linear flow scrubber, with the divers exhausted gas flowing down the center tube to the bottom of the scrubber canister.There is a dead space at the bottom of the canister for water to accumulate.The 02 injection is in the head and is added just before the exhausted gas heads down the center tube.The gas then comes up through the scrubber material where the C02 is removed.



The scrubber bottom plate and center tube being lowered into the canister, which is made from ABS plastic and is very tough.


Bottom cap and threaded rod, which comes up though the center tube and will hold the assembly together.


I didnít get pics of the canister being filled, but it goes like this.You stuff a bit of cloth or paper towel into the top of the center tube.Pour scrubber into the canister until you have the correct amount then slide the top screen down until it contacts the scrubber and then apply pressure to the top screen.Tap the side of the canister with a mallet, screwdriver handle or similar tool of choice.The scrubber settles and the screen descends into the canister to the correct level.


Then attach the scrubber canister to the head and tighten down the brass nut, seen here in the center of the head, with a large flat screwdriver until snug.



Breathing hoses being reattached, with SS hose clamps.


Slide tanks back in place and attach regs.


Unit stands up on its own, all thatís left to do is reattach backplate and harness and go diving.

The KISS is very well built and easy to work with.Gordon currently as of this writing has over 60 units in service with more coming.The unit is designed to be used at recreational depths, the exact scrubber duration and specifications can be had from the manufacturer as well as pricing and more technical information.This section was provided to showcase an excellent closed circuit mixed gas rebreather being made up in BC Canada.See Gordonís website at jetsam.ca - Jetsam Technologies Ltd..I have not dived this unit yet, however my good friends Alan Studley and Greg Grant both have them and swear by them.