Why does DIR reject quick disconnects?

[SeaJay]

The normal wingnut defense is to point out that they're made metal instead of lowly plastic, but that's bogus: a materials change does not eliminate a failure point. We can also say that wingnuts are tough, but they do break on occasion too. Ditto for anything else that have threads that can be stripped.


-hh

Ah, the old QD argument... With hh, no less. It' s been a while since we visited this point, man.

You say that "a materials change does not eliminate a failure point." To this I would disagree.

Would you drive a car made of paper mache'? Would you fly in an airplane made of particle board and newspaper? Would you use a parachute made of Hefty trash bags?

I contend that a change in materials DOES eliminate a failure point... Otherwise, you could define any and every rig as nothing more than a slew of failure points. QD's break, bolts strip, cloth of any kind eventually rots or comes apart. Eventually, every seal gives way and hoses, regs, and even tanks have a limited life expectancy. Sure, it may be years or even decades, but it's not unlimited.

Would you dive with a tank made of plastic (as in the "Romper Room" kind)? Of course not... That would be a failure point, if it survived it's first fill...

So yes, I would say that material and engineering can both either independently or cooperatively redefinie a failure point as virtually nonexistent - or even truly nonexistent.

 

[jonnythan]

Oh yeah, plastic that's 1/8" thin versus 5/16" steel.

I sure don't see the difference.

 

[ElectricZombie]

We should just weld our doubles together and then weld them to the BP. Instead of nylon webbing, I'm going to start using steel chain. The SS waist buckle can be replaced with a padlock. Next I'll weld the regulator DIN connection to the manifold because those pesky DIN connections cause so many problems.

Seriously though, citing wing nut failure is ridiculous. A continuous length of quality webbing and a good SS BP will not fail.

 

[Scubaroo]

Are ACB's DIR? They are sold by Halcyon and use plastic buckles.

Well if DIR is defined as what is in Jarrod Jablonski's Fundamentals book, then they *are* DIR. Page 91 or 93, I forget which.

 

[Scubaroo]

Seriously though, citing wing nut failure is ridiculous.

Dude, I've had wingnuts come loose one two seperate backplate rigs. And they were bloody tight at the start of the dive.

I've started using SS split washers underneath them. It's not a pleasant experience doing a shore exit with a frikkin tank under your arm.

Both times was with new hardware that hadn't seen salt water before, and in cold water - never been a problem except when new.

 

[SeaJay]

Yeah, we call them "lockwashers" Stateside. They work great.

That said, so do nylocks... I use nylocks on my singles rig, since my STA stays with my bp/wing when I remove the tank (cam straps).

I use lockwashers and wingnuts on a doubles rig or on a rig that I want to be able to change the STA without using tools.

 

[ElectricZombie]

Dude, I've had wingnuts come loose one two seperate backplate rigs. And they were bloody tight at the start of the dive.

The wing nuts didn't fail...you just forgot to put lock washers on.

 

[jonnythan]

The wing nuts didn't fail...you just forgot to put lock washers on.

Yeah! YOU failed!

 

[Whirling Girl]

Cam, I think the important thing about the question you asked is that the DIR answer is a matter of orientation. DIR taught me to ask questions about my gear, and the most important question was "is it necessary?"

Quick releases are not necessary. Beyond that doesn't really matter, though the fact that they can break and, for me, are hard to use in cold water with my drygloves, and impossible to use once my hands are cold, are reasons enough to avoid them.

Regarding backplates, I have a lovely 1/4 inch thick backplate from Scott Koplin which was beautifully finished on the edges. The double thickness helps prevent the fraying as well, though someone made the point that I was taught that fraying will happen at a slow enough rate that you can replace your webbing long before it is dangerous.

 

[zboss]

Ever set a tank down too hard on these plastic quick disconnect? The dive will be over before it ever started.

Have you ever dropped a tank on a perfectly DIR foot? The dive is ended before it begins... I suggest amputation followed by an all-black prosthetic made of neutrally bouyant rubber :11: p.