I don’t like it when hoses and hardware on a dive rig stick out and kludge up the equipment profile. In the water, my preference is to keep everything as simple, clean and streamlined as possible. The same is true for setting up, breaking down and post diving cleaning. But in the world of diving rebreathers, simple and streamlined sometimes seems more an elusive dream than a reality.
There are some things you can do to clean up a rebreather’s profile, and much of it begins with hose routing. There’s plenty of debate on this topic, but I’ll leave the pro-and-con discussions to the forums, and jump right into my own set up. Afterwards, you can decide for yourself if it’s something you want to do.
A look at the Dil side
The standard manifold block that comes with Classic Explorer features eight 3/8” low-pressure (LP) ports. It is from here I want all the gas supply lines to run as clean and accessible as possible.
Starting with the Dil supply, I change out the longer LP from the first stage for a slightly shorter 18-inch Miflex LP hose. At the end where it is to meet the manifold block I installed an OmniSwivel EL-S model 98-degree 9/16”-18 male to a 9/16”-18 female elbow swivel. To join it to the manifold block at the top I used a 9/16”-18 male to 3/8”-24 male adapter fitted to the port (far right) closes to the loop hose connection on the inhalation side.
The reason for this change that it makes it easy to disengage the dil reg from the rebreather for packing and servicing. In addition, I now don’t have a LP hose getting in the way the loop hose locking collar.
I like the OmniSwivel model because the knurled female end makes it easy to install and remove should I have only my fingers instead a wrench. Of course, most of the less expensive 90 degree second stage regulator swivels will do this as well.
For the ADV gas supply to the Classic’s head, I relocated the 11-inch LP hose’s position on the block from the center to the left 3/8 port. If there is one thing that I have learned through my many years of diving, it is that LP hoses tend to last twice as long when the part of the hose closet to the fittings are not subjected to hard bends. So instead of running the BCD power inflation hose off the end port of the block I installed an OmniSwivel PS-LP-2 model L-shaped swivel. Unlike their standard model PS-LP-1 which features only one 3/8″-24 female LP port, the PS-LP-2 has a second 3/8″-24 female LP port on the end placing the two ports as right angles – one for the power inflator to run over the shoulder, while a second covers the hose for the ADV.
As an added note: since I am not one for long hoses for BCD inflation, I use a rather short 18-inch Miflex LP BC inflation hose matched with 16-inch corrugated BCD hose fitted to a standard power inflator.
KISS Rebreathers was the first manufacturer to supply a BOV (Bail Out Valve) instead of going with the more conventional approach of using a DSV (Dive Surface Valve) with no open circuit bailout capabilities. When using a BOV, the positioning of the LP supply hose is critical to both comfort and function. To keep things clean, mine runs from the center of the block between the Dil supply and ADV lines. Because I favor the more flexible braided hoses like Miflex, Phantom and Rhino over standard regulator LP hoses, I am able to get away with a 30-inch length on the LP supply hose, which reduces the size of the loop running from the PS-LP-2 swivel to the BOV.
To join the hose to the BOV’s 2nd stage regulator, I fitted the LP hose with a OmniSwivel QDF-YM Female Quick Disconnect with 9/16 – 18 Male fitting. The same time, BOV is fitted with a QDM-YM Male Quick Disconnect possessing a 9/16″-18 Female Insert.
To keep the OmniSwivel QDF-YM Quick Disconnect from becoming locked on, I needed to cut the keyed locking mechanism on the slider off. This is a job that is easily handled with a dremel tool and cutting blade.
The thinking on this setup is that without removing the BOV from my mouth, I can quickly and easily swap the gas supply from one source to a second source so long as it also has a hose fitted with the same female OmniSwivel Quick Disconnect.
The O2 side
For easier dismantling of the rebreather for cleaning or travel, I reversed the direction of the hose between the MAV and the rebreather’s head so that the 9/16” female end comes to the head instead of the 3/8” male. To do this, I start by placing a 3/8”-24 male to 9/16”-18 male adapter in the elbow on the scrubber’s head. From there, you can do it in one of two ways that fit the 3/8” male end of the hose to the MAV.
Method one is to replace the 7/16 – 20M x 9/16 – 18M adaptor in the MAV with a 7/16-20M x 3/8-24F like the one on the button side below the micron filter for the 3/8” male to fit.
Method two involves leaving the fittings in the MAV as they are, and instead placing a 3/8″ Female to 9/16″ Female LP adapter (pictured right) on the end of the hose to the rebreather head. This way, when I dismantle the unit, I can disconnect the MAV from either end without any tools as it is snugged on finger tight.
SPG Hose Routing
For both Oxygen and Dil SPG’s, I favor running the high-pressure hoses up and over my shoulders and through both the upper and lower D-rings in the harness’s shoulder. The smaller 1.5-inch diameter brass SPG’s carried by brands such as Dive Rite, Zeagle and a few others are more suitable for sliding through the harnesses D-rings. Some harness D-rings will require the gauge go bare to fit through.
Just as important as the size of the gauges is the type and length of the high-pressure hose. Gauges should rest where they are within easy access for viewing, but also low profile and out of the way. I highly favor the braided high-pressure hoses made by Phantom in the 35-inch length. Like the Milflex hoses, the Phantoms feature an abrasion-resistant braided outer layer and are highly flexible. They are also far more reasonably priced than the Miflex version, and have never given me a problem in the four plus years I have been using them.
When two or more hoses run side by side, I like to bundle them together to keep things tidy. Short 2 to 4-inch sections cut from an old bicycle inner tube work great for this task.
Off board Bail-Out Routing
The amount gas in the KISS Classic’s onboard Dil bottle will not last more than a few minutes in an actual open-circuit bailout event. For this reason, I and many fellow KISS rebreather divers have our off board gas supply plumbed into the Dil supply network. For this, my off-board hose system comes off the block via a standard OmniSwivel PS-LP-1 model L-shaped swivel. This way the line runs over my shoulder and do through both D-rings on the shoulder harness, which makes finding the quick disconnects faster and easier. This subject will cover in a separate post.
List of Fittings & Adaptors for the Manifold Block:
One EL-S – OmniSwivel 98-degree elbow swivel with 9/16”-18 male to a 9/16”-18 female fittings.
One SZM-YM – OmniSwivel 3/8”-24 Male to 9/16”-18 Male Adapter for mounting OmniSwivel, or other brand elbow that swivels similar to EL-S model elbow.
One PS-LP-2 – OmniSwivel Pivoting Low Pressure Elbow featuring two 3/8″-24 Female ports with one 3/8-inch Male threaded end to run hoses for both BC power inflator and ADV line off manifold block.
QDF-YM – OmniSwivel Female Quick Disconnect with 9/16 – 18 Male fitting.
QDM-YM – OmniSwivel Male Quick Disconnect with 9/16″-18 Female Insert.
LP & HP Hoses:
Two 35-inch high-pressure hoses for the SPG’s – Highly recommend Phantom over Miflex.
One 18-inch LP hose for connection between the Dil reg and the manifold block. These can be Miflex, Phantom or any generic brand LP hose.
One 30 to 36-inch LP hose for the BOV – Recommend the braided hose brands for this application as they are flexible in nature than standard regulator LP hoses.