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Rinse It Right!
DON’T DUNK YOUR REGULATOR!!!
The Usual Advice
We have all read articles or heard well-meaning dive professionals tell us to remove our scuba regulator from the cylinder after the dive, put the dust cap on, and drop our regulators in the rinse tank for a good soak. This is information that has been passed from instructor trainer to instructor and down to the new student for many years.
It is BAD ADVICE, and
HERE’S WHY:
The “dust cap” is just that- good for keeping dust and spiders out of the regulator inlet.
Some dust caps are not waterproof on day one and very few are reliably waterproof over the long term.
The old “rubber ball style” from the seventies were probably the best: They had no interior space to hold water droplets and no o-ring to trap water either. They were resilient and not prone to scarring. They even created less turbulence while diving.
If your regulator dust cap leaks in a rinse tank, water enters directly into the high pressure area. This can leave deposits, cause corrosion and encourage bacterial or fungal growth.
What are the possible results?
The inlet filter might plug, restricting ease of breathing.
The regulator may have a free flow failure the next time you try to use it.
The regulator may behave erratically or just be hard breathing.
You might breathe something pretty nasty that grew in the moist insides your regulator or hoses.
You might lose your regulator to internal damage of sealing surfaces in the body.
You might be faced with a higher than normal repair bill at next servicing.
You might void your warranty.
There is a small chance that your regulator could fail to supply air.
What else can happen during a rinse tank dunking?
All scuba regulators have open high-to-low pressure passages when cylinder pressure is not on, so water entering through the scuba cylinder inlet can pass into any hose connected to the regulator. It was bad enough to think about the septic growths in the first stage, but now we see they can be flourishing in the second stage hoses, too! Yech!
Water might enter through the second stage, up the hose, and into the first stage. This can occur in a couple of ways:
One is when the diver tries to be thorough in cleaning and presses the purge button, thus opening the low pressure seat and allowing water past the orifice and into the hose.
The other is when the regulator second stage design is such that the low pressure seat is not pressed against the orifice except when the air pressure is on. The design idea was to protect the seat from the effects of continuous spring pressure, but with a good dunking, it could drown the whole regulator!
Your second stage will exit the dunk tank with a good fill of dunk tank water to grow some nasties later. Yum!
The technical skinny on why your regulator might fail:
If water enters a diaphragm type regulator, the shaft of the small piston cone or high pressure seat might stick, which probably will result in a free-flow failure the next time you try to use the regulator. This can result from losing the clearance on moving parts to salt crystals, mineral deposits or corrosion crud. It can also result from a deteriorated spring.
Although the springs and metal moving parts are corrosion resistant, they can and do corrode under the right conditions.
Most standard balanced “flow-through” piston regulators are more resistant to failure from water entry in the high pressure inlet because without tank pressure the piston is in a position that places the sealing part of the shaft beyond the internal o-ring.
Some “new-fangled” balanced piston flow-through regulators have added centering and o-ring backing parts that might negate the advantage of the old tried and true design. If the internal circlip that holds all these parts in place fails, you can expect lots of bubbles from all the wrong places and a regulator that needs an overhaul at the least.
Balanced “flow-by” or unbalanced piston regulators have the o-ring seal on the piston, so the danger lies in crud accumulations or pitting on the piston bore of the regulator body.
If it is a balanced flow-by that uses Beville cupped spring washers to move the high pressure orifice to compensate for changing tank pressure, it is possible for the stainless steel washers to rust to the point that they just crush. The result is total loss of air flow. I have only seen it happen once, but I can attest that it can.
Sherwood's popular flow-by piston regulator was designed to waste a tiny amount of air instead of having the salty or silty ambient water enter open holes in the regulator. The ambient water pressure boosts the piston spring pressure as you dive deeper.
With the Sherwood, there is another problem with dunking the regulator: Water can enter either through the tank inlet or the mushroom/umbrella valve (air-bleed hole) if there is no air pressure inside. This can cause the tiny sintered metal filter that meters the compensating bleed air to plug.
On subsequent dives, there will be no bleed air. This will prevent your regulator from adjusting the intermediate pressure for varying depths and can allow sea water to leak past the mushroom valve and become trapped inside the piston spring chamber of the regulator. This is a really common problem that comes from dunking the unpressurized regulator and it requires the replacement of the relatively pricey bleed filter. On the older models this means also replacing the entire piston.
Sherwood has possibly the least expensive parts of any manufacturer, but why negate that advantage?
The simple alternative:
My “idiot and design engineer proof” method of rinsing equipment!
1. Leave the regulator on the cylinder and pressurized. Now you can safely dunk the tank if you wish. (Safe for the regulator, yes, but maybe NOT so safe for your back!)
Safer for both you and your equipment is to use a soft stream of fresh water (instead of the brackish dunk tank that just rinsed the gear of that fellow who got sick underwater and now has fast food stuck in his exhaust valve). Rinse the gear as follows:
2. Rinse off the exterior surfaces.
3. Try to run water into the submersible pressure gauge swivel if you can, and rinse the compass well so the bezel doesn’t stick. Get those computer buttons, too.
4. Remove the BCD from the cylinder but leave it connected (or reconnect it) to the inflator hose. Depending on your cylinder strap type, removing the BCD might involve turning off the cylinder valve, removing the regulator, sliding off the BCD, remounting the regulator to the cylinder and turning the pressure back on. This isn’t an essential step, but it will make rinsing the BCD easier if it is off the cylinder
5. Run water through the mouthpiece of your second stage so that it runs out the exhaust port. Go ahead and press the purge button a time or two to move the internal parts. (Since the cylinder pressure is on, no water can run into the hoses.) Put a finger over the mouthpiece when pressing the purge so that the venturi assist doesn’t suck in the diaphragm and put the air flow into a wide open free-flow. (It won’t hurt anything but it is annoying when it happens and everyone will look at the sound to see whose equipment is out of control.)
6. If you have a piston regulator with body barrel openings that allow water entry when diving, flow some water into one of the openings while pressing the second stage purge button a few times. (This will move the piston up and down to expose and rinse all of the sealed portion of the shaft plus maybe help pump contaminants from the spring chamber even though the piston has a very short stroke.)
7. If you have a diaphragm regulator that is not environmentally sealed, there will be a hole to the spring chamber in the regulator body furthest from the cylinder valve. Run a little water in there and hit a second stage purge button a few times.
8. With no water flow into the mouthpiece, press the purge and shake the second stage to try to get most of the water out. (You don’t want a wet environment for nasty culture growth inside the second stage if you can so easily avoid it.)
9. Repeat with the octopus second stage, of course.
10. Open the oral inflator valve on your BCD inflator and run water through the mouthpiece into the BCD bladder. Dump the water from the BCD dump valve. Repeat.
11. Fill the BCD with air and operate the dump valves.
12. Fill the BCD with air and leave it at least partially inflated. (This will keep the bladder from sticking to itself and will help prevent any sharp salt crystals from cutting it)
13. Remove the BCD inflator hose quick disconnect and flush the inside of the hose quick disconnect while moving the sleeve up and down to rinse off the little ball bearings and springs. Shake out the excess water. Do NOT flush inside the BCD inflator connector as it only had air in it, not water.
14. Turn off the cylinder valve, remove the regulator first stage and while holding the regulator inlet away from the cylinder valve so as to not get any water spray (maybe your dry thumb is covering it), blow all traces of water from the dust cap with compressed air from the cylinder.
15. Install the dust cap and you are finished! Congratulations!
Now DO NOT store your regulator in a watertight case! (I DESTROYED a regulator that I thought was totally dry by making this mistake). Let it breathe. I have buddies who keep their regulators in their clothes closet with the dust cap off, just in case some moisture is inside. Their regulators look good inside when serviced, so I think it is a good idea. On the other hand, storing in a dark humid location with the dust cap off will change the color of the filter in no time! (I’m still not sure if the green is corrosion or mold or both.)
I typically get hundreds of saltwater dives in between regulator overhauls by using the above procedures. When I disassemble the regulators, they are usually quite clean inside, just needing a light bath and fresh lubricant on new o-rings. I made plenty of mistakes before learning what works so that you don’t have to!
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