"Dust Caps" and rinsing rant

[FatCat]

Question for you. My DIN caps have a little hole in them so I've been reluctant to do what you mention above.

What up with that?

Buy new DIN caps.

If you want to dunk your reg, be sure to use the right cap for your reg. Use a five turn cap for a 200/232 bar reg and a seven turn cap for a 300 bar reg.

The five turn cap will effectively seal a 300 bar reg, but vice versa you risk infiltration.

 

[fdog]

I'll stand up in part-defense of Jetwrench.

Who has a pretty good handle on care of their gear? Experienced divers. Who wouldn't ask the question. And who use common sense. And actually might RTFM.

The people who ask the question are neophytes...who will do as they're told, and are generally too overwhelmed to apply detailed thought as to what's behind the advice.

The dustcap advice might not work so well, if the o-ring is missing, or hard and cracked, or the cap looks like the one below; probally not things these early divers are looking for.

Or, these folks might subscribe to the "if a little rinse is good, a long soak is better" school.

I rinse my regs under pressure, just because I can be thorough and not worry about a drop of water. But, that's a personal choice, and the way I was taught. I'm not an evangalist about it or anything.

And besides, it's called a dustcap. Sheesh.

All the best, James

 

[miketsp]

..snip..
It's a "dust cap"!

I'll say it again.

It's a "dust cap"!

My "dust caps" have o-rings which provide an excellent seal. I check their presence and condition every time I put the caps in place. No problem if I need to soak the regs for a couple of days to get all the salt off after a long trip.

Anyway it's only called a "dust cap" in English. In Brazil it's called a "chapeu de bruxa" which translates to "witch's hat", for obvious reasons.

 

[Jetwrench]

Gosh Jet, this seems to hit a hot button for you. Why the passion on this? Have you had a couple of regs dunked by friends?

Its a sin to see a perfectly good reg compromised by careless rinsing or soaking, but it seems to me that a little care and attention can avoid that. For fresh water dives, rinsing is fine, but for salt water, a good soak will prevent salt corrosion in the gazillion nicks and crannies in the gear. Your cautions about protecting the 1st stage are sound, but you seem convinced that dust covers can't seal. Do you have some observations regarding why that is?

I guess everyone has a pet peev(sp?) so you could say this one is mine. It's a carry over from my work(refer to user name). I really began to notice how many people I saw on my last dive trip that used poor rinsing practices. Cap it off and drop er in a tank with who knows how much other gear in it. Where did they get the idea that's the way to do it? I politely mentioned it to one man who looked at me oddly and asked why not. After a brief explanation he thanked me for pointing it out and shook my hand before he left.

I see it this way. There is no way to be absolutely sure the cap will be waterproof time and time again for the purposes of soaking. Even caps with orings get worn, deformed, cracked, or even fall out and are lost. Does the cap get the same attention as the rest of the reg? Many times it doesn't. Second, without the pressure on the reg, can one be absolutely sure the purge valve on the second stage and alternate is fully seated? These points are why most mfg's (all the ones I am familiar with) discuss applying tank pressure first. It's just good maintenance.

MB, to answer your questions, no I have not had a reg issue(knock on wood) which I believe is because I'm aware of the problems I can cause by not following some simple instructions. My instructor had the smarts to emphasize good gear care from day 1. Can dust caps seal? Yes. Every time? Maybe. Will they eventually leak? Probably. As I have said before, everyone can do whatever they feel appropriate for them, just remember that it may not be appopriate to pass it along to someone with less or little experience looking for sound advice.

Jet

 

[redacted]

What many are refering to as a "dust cap", the scubapro manual refers to as an "inlet protector".

Care instructions are: "...rinse unit thoroughtly with clear water...taking care of the following cautions to avoid water entering inside: 1.- Ensure that the HP inlet protectors are covered (1st stage)."

 

[ZoCrowes255]

According to the NAUI Openwater Test a regulator should be rinsed with the DUST CAP in place OR with a pressurized tank. If a dustcap is put in place properly the amount of water that can get into the first stage is insignificant.

BTW I work in a dive shop. I help to service regulators almost EVERY SINGLE DAY and I have yet to see any moisture get into the first stage if a reg is rinsed or soaked properly with the dust cap in place.

 

[diversteve]

My Atomic has a hard durometer rubber cap that seems designed to seal the first stage, it actually has a 1/8" recess molded into the underside so it fits right over the fs opening and seals below the flange on the mating surface when pressure is applied. So I just make sure it's on tight before I rinse.

 

[Jetwrench]

What many are refering to as a "dust cap", the scubapro manual refers to as an "inlet protector".

Care instructions are: "...rinse unit thoroughtly with clear water...taking care of the following cautions to avoid water entering inside: 1.- Ensure that the HP inlet protectors are covered (1st stage)."

"rinse", not "soak". Check the first sentence of my first post. There are even posts on this thread where soaking for hours, if not days, is the practice. Can't find that in my manuals. I just hope I made a point and increased the awareness. That was my goal here.

 

[MB]

I guess everyone has a pet peeve... I see it this way. There is no way to be absolutely sure the cap will be waterproof time and time again ... My instructor had the smarts to emphasize good gear care from day 1. Can dust caps seal? Yes. Every time? Maybe. Will they eventually leak? Probably...

Well said amigo. Its a probability game. I've seen too many cracked dust caps to assume that they seal, so my rule is check every cap, every time. (sorta like analyzing a gas mix) I'm less inclined to ban soaking, but I'm a major nuisance when friends or students don't check their caps. And I explicitly TEACH them to do that.

 

[Marek K]

Jet, I've got to disagree with you too. You said to check the reg's manual; but they all seem to indicate that rinsing or even soaking the first stage with the "dust cap" on is at least okay.

Let me add to the others:

The Sherwood manual says, "With the dust cap securely in place, rinse the first and second stage in clean fresh water." Not a word about pressurization.

The Oceanic manual says, "Install the first stage protector cap and tighten the yoke knob (or install the DIN thread protector cap). If possible, immerse the entire regulator assembly in a warm fresh water bath and soak for one hour, preferably while pressurized."

Hard to soak for an hour, though, with a tank attached...

And on many boat trips where tanks are provided, like at a resort, the tanks are handled separately by the crew. Divers don't even have tanks available when rinsing their equipment.

That having been said, you do reinforce an excellent point about making sure no water gets into the first stage.

my new Sherwood has a soft rubber dust cap -- it doesn't have an o-ring, but I'm confident it's water-tight enough to withstand a dunking in a fresh water tank. But we also have a very old Sherwood, whose dust cap is hard plastic. It fits very snugly over the orifice, but I'm not as confident of its water-tightness.

Anyone know a good online source for dust caps with o-rings? I see some caps online, but it's impossible to tell how they're constructed.

--Marek