How Do You Add To The First Stage?

[GLENFWB]

I am getting a pressure gauge to back up my AI computer. I have never messed with my first stage. Do you just screw the pressure gauge hose in to an available auxillary port on the First Stage? Do you have to use anything to seal the threads...something like a teflon tape? Can I do this or should I bring it to my LDS to put it on? Seems pretty straight forward so was hoping I could do it myself.

Would like to hear from some of you who have done this before...

Thanks

 

[fishb0y]

Yes, it is easy and straight forward. However, if you bought the gage at a LDS, have them attach it.

 

[Tassie_Rohan]

Do you just screw the pressure gauge hose in to an available auxillary port on the First Stage?
Thanks

Yep. The high pressure (HP) one.

Do you have to use anything to seal the threads...something like a teflon tape?
Thanks

Nope.

Can I do this or should I bring it to my LDS to put it on? Seems pretty straight forward so was hoping I could do it myself.

Yep very easy - do it yourself. Tinkering with you gear is one of the joys of scuba diving - why should dive stores have all the fun?

Cheers
Rohan.

 

[skynscuba]

Some regs, such as my Titan, only have one high-pressure port.

 

[CODMAN]

Don't forget to lightly lube the O-ring before installing! To prevent tearing it when tightening. I bought a little quatity of silicone lube from the dive shop for 6$. Probably could have got it cheaper if I had shopped around. For 6$, you'll have enough for all your needs (any O-ring on your various gear) for a long long time...

Hope this helps!

 

[divefreaky]

it is simple but you need make sure it has 2 hp ports first.

 

[Benthic]

I am getting a pressure gauge to back up my AI computer. I have never messed with my first stage. Do you just screw the pressure gauge hose in to an available auxillary port on the First Stage? Do you have to use anything to seal the threads...something like a teflon tape? Can I do this or should I bring it to my LDS to put it on? Seems pretty straight forward so was hoping I could do it myself.

Would like to hear from some of you who have done this before...

Thanks

In spite of what some may tell you (your LDS included, most likely), it's not rocket science and you can easily do this yourself.

First of all, as others have mentioned, you new SPG is going to need to be attached to a high pressure port. Look at your first stage, where the AI computer is connected an you'll likely find the letters "HP" stamped next to that port. You'll need to find a second "HP" port on the first stage for your SPG. If you've only got one HP port, you're in trouble.

With an allen key, remove the plug from your chosen HP port. (Save the plug in case you need it some time in the future.)

Lightly lubricate the o-ring on the end of the SPG hose with some silicone lubricant, Christolube, Krytox, etc. (This is nice to do if you've got some lubricant handy--but it's not exactly a show stopper if you don't.) Oh, and use something intended for scuba gear. No WD40, vaseline, axle grease, etc.

Hand thread the hose from the SPG into the open HP port until it's snug and you can't turn it any further.

Using an appropriately sized wrench, tighten the hose a bit more so it's snug. If you can loosen it again with your hand it's too loose. But don't crank it down excessively hard either. That first stage is made of brass, which is a soft metal. If you strip the threads in the first stage you're in big trouble.

Put the first stage on a tank and pressurize the system to check for leaks (a little soapy water is handy here).

That should about do it.

Of course I should point out that I'm not a certified scuba tech or anything like that, so this is all at your own risk. I've been doing my own regulator re-builds for years though. This is the most basic of regulator work and I'm sure that you'll be just fine.

Brian

 

[RICHinNC]

Just fight that urge to "tighten it jussssssst a little more".

 

[noobascooba]

I attached a new inflator hose to my LP port and I didn't lubricate the O ring because I wasn't sure if my silicone grease was a potential fire hazard when using nitrox. I'm assuming it wasn't because I only use nitrox within recreational limits, it was the LP port so the partial pressures of o2 aren't that high and the supplied O ring wasn't a nitrox O ring, but I thought this thread was a good opportunity to check...

I guess in a long-winded way I'm asking if regular silicone grease is nitrox compatable.

...and what is the deal with the green O rings you get in nitrox tanks? What are they made of, and if the O rings are a potential source of fuel why are regular O rings ok on the hoses?

Sorry if this is a bit of a hijack but I thought it was important

ns

 

[jviehe]

I attached a new inflator hose to my LP port and I didn't lubricate the O ring because I wasn't sure if my silicone grease was a potential fire hazard when using nitrox. I'm assuming it wasn't because I only use nitrox within recreational limits, it was the LP port so the partial pressures of o2 aren't that high and the supplied O ring wasn't a nitrox O ring, but I thought this thread was a good opportunity to check...

I guess in a long-winded way I'm asking if regular silicone grease is nitrox compatable.

...and what is the deal with the green O rings you get in nitrox tanks? What are they made of, and if the O rings are a potential source of fuel why are regular O rings ok on the hoses?

Sorry if this is a bit of a hijack but I thought it was important

ns

Well, you should know this from your nitrox class, so it may be a good idea to go back and review the book. But, to answer your question, silicone is not 02 compatible. However, regulators do not contact more than 40% in recreational nitrox, so it doesnt matter. Green ORings can be made of anything, but depending on the manufacturer are probably viton, which has a higher combustion temperature, iirc. Just dont think that if its green its automatically compatible. O Ring makers can make them any color.