Dump Valve, Part II

Jax · Dec 4, 2011

Going over my gear, I find I needed to replace my dump valve line. It wears against the hole of the cap, since the cord is pulling directly sideways.

As I activated the pull, I noticed and felt the binding, then sudden full open. :hm:

The cord's fault, not the dump valve?

So, messing around, I came up with this. I understand that I will have to cut the itty bitty tie wrap every time I want to unscrew the dump valve, but I have lots of them.

385421_336275666387895_100000163925455_1615406_1661265333_n.jpg

Can anyone see any reason to NOT dive it this way? The cord pulls way smoother than it did before,
and I can open it "just a squeak", much more fine control.

tbone1004 · Dec 4, 2011

can't see any reason not to as long as it pulls and closes easily

Dive-aholic · Dec 4, 2011

Great idea! Looks good. I may have to try this on my Nomad...if I ever dive it again...

redacted · Dec 4, 2011

I would expect the soft tubing to wear and eventually allow the hard plastic cap the again fray the string. How about if you also round and smooth the outer edge of the hole in the cap where the pull cord makes contact.

Paul S · Dec 5, 2011

Sounds like what you really need is a little rubber grommet around the string, in the hole of the dump valve. It's is a little rubber tube that the string passes through, and protects the string from the edge of the plastic. It flares at each end to hold in in place either side of the plastic.

Grommet - Wikipedia, the free encyclopedia

Depends how much space there is around the string.

Sort of thing you might be able to pick up in a hardware store for a few pence / cents if you can work out what size to get.#

(Interested because I'm things of making the same modification to my nomad)

Jax · Dec 5, 2011

Dive-aholic:
Great idea! Looks good. I may have to try this on my Nomad...if I ever dive it again...

Paul S:
Sounds like what you really need is a little rubber grommet around the string, in the hole of the dump valve. It's is a little rubber tube that the string passes through, and protects the string from the edge of the plastic. It flares at each end to hold in in place either side of the plastic.

Grommet - Wikipedia, the free encyclopedia

Depends how much space there is around the string.
Sort of thing you might be able to pick up in a hardware store for a few pence / cents if you can work out what size to get.#

(Interested because I'm things of making the same modification to my nomad)

Paul, the hole is pretty small - the #36 almost didn't fit through due to a bit of mushrooming of the melted end.

Besides, it's a penny's worth of line. I'd rather keep replacing it.

The most important part is there is a whole lot less binding going on during the pull.

SeaCobra · Dec 5, 2011

If I understand correctly, you have made a little conduit out of a small plastic tube for the pull dump cord? If so, nice job. Similar applications have been used on bc's with a pull dump in the shoulder like the scubapro classic and others, so its a sound concept. Taking the time to inspect the pull dump cord and that all "thru-hull" fittings are secure is a regular pre-dive routine of mine.

Mitchell Teeters · Dec 5, 2011

If you could find a small piece of delrin rod you could epoxy it so that the string goes over it creating round pivot point.

sent via nookcolor N2A.

Jax · Dec 5, 2011

TNRonin:
If you could find a small piece of delrin rod you could epoxy it so that the string goes over it creating round pivot point.

sent via nookcolor N2A.

The problem with that would be getting the valve screwed on the same way each time. A small delrin torus shape would work.

Mitchell Teeters · Dec 5, 2011

Rings a large enough ring then and attach it with epoxy.

sent via nookcolor N2A.

Dump Valve, Part II

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