Minor Rant about DIN 1st Stage Dust Cap

[MichaelMc]

I have thought about that.

I usually refill water bottles with tap water while on dive trips. I use the bottled tap water to rinse my first stages before changing tanks during the SI. I then use the remaining water to rinse the regs from top-to-bottom before depressurizing while on the boat ride back to the dock after the last dive.

cheers,
m

The pressurized sprayer might be too big depending on the boat, depending. A half gallon is enough for my metal gear bits. A hand sprayer would certainly be good for the boat. The stream is much more efficient than the pour. I can get inside all my boltsnaps.

 

[markmud]

The pressurized sprayer might be too big depending on the boat, depending. A half gallon is enough for my metal gear bits. A hand sprayer would certainly might be good for the boat. The stream is much more efficient than the pour. I can get inside all my boltsnaps.

Definitely a po-man's pressure washer!

 

[broncobowsher]

After a salt water dive, on the way home, gear up and do a quick fresh water dive. I've done it as a 5-minute 20-foot dive. de-salts stuff great.

 

[PfcAJ]

View attachment 508033 Hey Doc...

As has already been stated...I too have been soaking/hose flushing 2nd stage regulators for years with no water intrusion problems...the key is not to press the purge button on the 2nd stage if it's not pressurized...the knife edge will seal out water against the LP seat...no problem...

For all DIN 1st stage applications...push/pull ''dust caps'' should be replaced with threaded DIN caps...with the hanger strings threaded through a diagonal drilled hole in the end of the cap...if the caps are of the type that are not drilled through...they will provide a water tight seal against the captured ''O'' ring on the male DIN fitting...soak and hose flush to your hearts content...

Delrin versions are the best...Delrin is very stable...not affected by heat/cold expansion/contraction...

Four dollars at DGX...plastic versions are $2.

Dive shop dunk/rinse tanks are only clean in the morning...if then...when salt water diving the most important thing when rinsing...regardless of what it is...to clean while everything is still wet...if you wait until everything has dried...and salt crystals have formed...you've waited too long...and you've just started a love/hate relationship...your gear will hate you...the dive shop service departments will love you...

Best...

Warren

The majority of those DIN caps don’t really seal, either.

If you look inside, it most likely doesn’t have a machined step in the center, so the oring isn’t in contact with anything. A few of them are machined “properly”, but most aren’t because it’s cheaper.

 

[doctormike]

View attachment 508033
Dive shop dunk/rinse tanks are only clean in the morning...if then...when salt water diving the most important thing when rinsing...regardless of what it is...to clean while everything is still wet...if you wait until everything has dried...and salt crystals have formed...you've waited too long...and you've just started a love/hate relationship...your gear will hate you...the dive shop service departments will love you...

Best...

Warren

Oh, yeah. Exactly. I would never soak my reg in a shop rinse tank. If I needed to soak it (for example, if it had been used in salt water and then dried without rinsing, I would pressurize it and soak the second stage in a bucket of clean warm water. Rinsing the outside of the first stage should be enough.

But I usually just flush it before it dries...

 

[W W Meixner]

The majority of those DIN caps don’t really seal, either.

If you look inside, it most likely doesn’t have a machined step in the center, so the oring isn’t in contact with anything. A few of them are machined “properly”, but most aren’t because it’s cheaper.

Good point...

The DGX Delrin threaded caps have the step...you can feel the captured ''O'' ring seating as you tighten them...not so sure about the less expensive plastic version...four dollars...versus two dollars...not exactly a fortune...and always good to have a couple spares...

Best...

Warren

 

[Divectionist]

This is the design facilitating the O ring seal with that step inside.

 

[TrimixToo]

This one does say it has an o-ring seal in the description.
Aluminum Regulator Din Cap – Innovative Scuba Concepts

If you get salt water on either the male or female versions, Bad Things Happen. Eventually. Delrin rules.

 

[TrimixToo]

\*

Been soaking DIN regs with only the 'dust' cap for over 20 years. No problem.

<snip>

Same here. But mine are all the screw-on kind.

[Edit] ...and all seal properly, having a machined surface for the O-ring to seat against.

 

[Bigbella]

I'm a photographer and don't believe that stuff about the cameras being more vulnerable under less pressure. That may been true on some of the equipment that actively relies on pressure to help seal, but the clamshell type derive no benefit from it.

I think the issue with that is jostling in the dunk tanks.

I am a photographer as well; and it is a matter of physical law, that a static or dynamic seal (a toric joint) increases its sealing properties with added pressure -- to a point; then failure --flooding -- occurs. I was also involved with underwater housing designs in the mid-1990s and that very issue had been part of the design process from the beginning.

There are currently a number of products designed to, via a hand pump, pre-compress o-rings within a housing before a dive, just to remedy that issue.

Why else do most professional photographers have their rigs handed to them, or on a line, rather than just jumping in the drink?