jump to navigation

Adjusting the second stage August 8, 2012

Posted by Chris Sullivan in Equipment, Technical Diving.
Tags: , , , , , , , ,

My Apeks TX50 second stage came back from service a little too “hot”. It leaked slightly unless the venturi control was screwed at least 1/2 way in. The first thing I did was check the intermediate pressure coming from the 1st stage (an Apeks Black Pearl*). To do this I borrowed a pressure gauge from my local dive shop, immediately noticing that it consisted of a standard workshop pneumatic pressure gauge with a standard 1/4″ fitting fitted with an adapter for a standard inflator hose. I have to find me one of those adapters.

The IP was 130 psi (~9 bar), which is fine. So next I simply unscrewed the 2nd stage from the end of its hose with an 11/16″ wrench and gave it a 1/4 turn clockwise. This stopped the leak, and it breathed fine on the surface, but I observed that the flow when pressing the purge valve was weak. So it back it off an 1/8th of a turn (or maybe a bit more) and then it was perfect.

* Those of you familiar with the Black Pearl might be wondering why I had a TX50 second stage on it. The story started on a recent trip to Tobermory Ontario where I was about to dive the wreck “Forest City” in my doubles. My doubles setup as 2 Apeks Tek 3 regulators with a TX50 second stage as the primary, and an Apeks “Egress” (more about that later) as the backup second stage. When setting up my gear on the boat, I noticed the hissing coming from the TX50 and swapped it with the Black Pearl second stage (like a souped-up TX200) , and haven’t changed it back.

The Egress is a reasonable regulator for it’s purpose. It has no controls – and I’ve compared it to a backup ‘chute. You don’t need (or even want) fancy stuff on something that’s only there to take you to the surface – and I’ve breathed it at deeper than 150’ without undue effort. Having said that, and with some deep diving coming up, I’m planning to use the TX50 as a backup second stage on my tec setup, even though that leaves my poor Black Pearl second stage with two Egresses. The Egress points straight up when mounted on a necklace and invariably free flows when I jump in the water from the dive boat in the Tec gear (it’s fine with my recreational setup where it’s pointed in a different direction). That’s enough to make it less desirable for technical diving where one needs to aim for perfection.



No comments yet — be the first.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: