Scuba Pro Dust Caps

[OE2X]

I just had two MK25's and four regs. serviced. The tech pointed out that the attached SP yolk style dust caps are hollow and will hold up to a 1/2 oz. of water. This water can then go into the first stages and hoses and crystalize. While neither of my reg sets had any problems it would seem that this small design flaw could create some real issues. Replacing this type of dust cap with a solid cap seems like the thing to do, or:

I store both my setups in their own small individual rubbermade boxes. From now one I'll leave both my 1st stage and tank dust cap in my primary setup's box when I'm diving. This way neither one will get get wet.

There is a very interesting thread with some excellent observations/opinions from about 2 years ago concerning this.
http://www.scubaboard.com/showthread.php?t=7827&highlight=dust+caps

 

[IslandHopper]

I have the MK16 .... same cap ... i just blow it out with air (from the cylinder) before putting it on the reg. Not too hard and dries it out in about 2 seconds.

 

[yak]

Yep. The first thing I did was replace that cap with a solid one.

 

[OE2X]

While I don't pretend to be a regulator tech. my thoughts are:
1. When blowing off the cap, unless your first stage is completely dry you may blow water into it.
2. It rains a lot here in the NW so nothing dries until you get undercover. Ever seen mold grow on the insides of windows? I wish I could dry my gear in the sun, but we only see that strange orb for about 2 weeks every year
3. When the cap drys unless you have only been diving in fresh water, then there will be a salt residue that may be able to get into the first stage. I guess you can prevent this by completely rinsing off your first stage andd cap while it's still attached to the tank. Most places where I dive I don't have that ability.

I had both my setups DIN converted and the dust cap seems larger. Guess I'll just toss the cap in the reg bin and keep a spare in my SAD kit.

 

[DA Aquamaster]

An house of water takes up the volume of a 35 mm film canister so no way is the dust cap on an SP reg going to hold that much water. But despite the exaggeration, the point is valid that you don't want water in the cap when you put it on the reg.

Blowing the cap off with air from the tank should be standard practice and takes only a a short time to do properly. Getting water in the inlet hole on the reg while blowing the cap dry is just not a problem with a little care to turn the inlet portion of the reg away from the cap and air flow when blowing the cap dry.

You can replace the SP caps with flatter caps, but they should still be blown dry. The Trident caps for example are relatively flat but also use an o-ring that can trap moisture if they are only wiped dry.

Removing the cap is one option and has the benefit of removing a potential item that can snag or wrap around a flag line, fish line, etc.

Of course most tanks have a valve cover and this will also be flopping around during the dive. My preference is to use the SP cap and then stuff it inside the tank's valve cover. This keeps both the cap and the valve cover from flopping around during the dive and the relatively stiff retainer on the SP cap keeps the whole thing motionless and out of the way during the dive if you tuck it down under the reg. It should be tucked away on the side opposite the tank valve knob to enure access to the valve knob is not restricted.

 

[coberry7]

Good advice DA Aquamaster. Even with the solid ball caps on some regs, I still blow them dry. It really is too simple to avoid blowing water into the 1st stage. If it is raining where you dive...well, use an umbrella.

I've never had, nor heard of anyone else having an issue with dried salt in a reg cap causing problems with the reg.

 

[will_tekkie]

i dont like the SP CAP..but it is just my opinion. I prefer a solid one so this can be dryed easily and seems more water proof..in fact i changed the standard cap in all my SP...