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View Full Version : Piston v Diaphragm



Sarah
01-04-2007, 06:53 PM
I would say my diaphragm has always worked for me.....no, a REGULATOR style of diaphragm, lol.

Scott
01-04-2007, 08:22 PM
Funny iDiveChick;)

First of all.. let me say that I receive any bonuses, money, benefits, or gifts from either of the two companies whose products I will talk about. Other then the physical description of the items, everything is my opinion.....

I started out with a Dive Rite RG2500 set, with the balanced diaphragm RG1208 first stage and a pair of RG2010 pneumatically balanced second stages. They worked wonderfully for my single tank recreational diving. I added a second RG1208 on an H-valve for my Cavern and Intro to Cave course. They proved very reliable and easy to breath for me.

When I moved to doubles, because of knee trouble I decided to use a side mount configureation. With the conventional second stages, the LP hose is usually fed in from the right side. This meant I either *HAD* to feed my left tank's LP hose across my front to my right side, and use a swivel to connect it to the regulator.. which didn't feel comfy to me, or use a longer hose, route it around my back, and to the right side of my neck. Problem with that was, a 7 foot was too long to do that without snaggy excess, but too short to tuck any of it into a hose strap on the tank.

So.. I did some research, and purchased a pair of Poseidon Xstream Deco's. I didn't need them to be oxygen cleaned, but the price was the same, so I went ahead and got them. They are ambidexterous, having the LP hose feed in from one side, the exhaust on the opposing side, and they operate equally as well whether right side up, or upside down.
Their first stage utilizes a balanced rolling diaphragm ball valve.

Now.. some people may say that I am abusing the color coding, by utilizing a regulator marked for pure oxygen.. Well, that's simple to correct with the Xstream's.. the colored coded cover on the second stages is a piece of rubber that is easily installed and removed, even underwater, and can be replaced with the proper color for the gas I am using... *NOTE* - my regulators are NO LONGER considered pure oxygen compatible, as I have not maintained them as such.

Using these ambidexterous second stages allows me to route one directly from each tank, and allows me to use a 7 foot hose on each tank, tucking the just the right amount of excess into a hose band.

I must say, that while I was satisfied with Dive Rite's regulators, and would not hesitate to continue to use them with a back mounted tank system, I feel that the Poseidon's exceeded my expectations, and feel as though they are easier to breath from. And as a bonus, they make for nicer hose routing for side mount =)

Wow.. how was that for a run on sentence. Well.. I feel the urge to have an early dinner.....

Take care everyone,

Scott

Diverdaniel
06-05-2007, 11:01 PM
diafragm is easier to replace HP seating when in a rutt.
piston has less moving parts........
a tough one.
rightnow im ussing both.

seasnake
06-06-2007, 05:09 PM
I use both ... no problems with either style.