Fundamental knowledge for a hose replacement

[josenandopr]

Hi there

I just sign in to this forum
Well today October 23 I and my partner's did a night dive. It was an amazing experience we saw from 20 to 30 lobsters all together. But had a problem with my octopus one hoses had a lick. I want to change the hose my sell to economize some money

It a 5000 psi hoses that goes to the gage. Since I have never done this type of work I was looking for someone that could point me at the right direction.
Do I have to pay attention when I am loosing the hoses or tighten it?
Is there a specific hose for the gages?

Give as much information you can. I hope this Post can serve people in the future when they encounter the same situation.

Best Regards

 

[350xfire]

Hi there

I just sign in to this forum
Well today October 23 I and my partner's did a night dive. It was an amazing experience we saw from 20 to 30 lobsters all together. But had a problem with my octopus one hoses had a lick. I want to change the hose my sell to economize some money

It a 5000 psi hoses that goes to the gage. Since I have never done this type of work I was looking for someone that could point me at the right direction.
Do I have to pay attention when I am loosing the hoses or tighten it?
Is there a specific hose for the gages?

Give as much information you can. I hope this Post can serve people in the future when they encounter the same situation.

Best Regards

Not hard at all. Remove the old one and replace with the new one... The octo hose will be a low pressure one the pressure gauge one will be the 5000 psi one. A dive shop should not charge very much, if at all with purchase of a new hose.

 

[DA Aquamaster]

Low pressure hoses have a 3/8" fitting while high pressure (SPG) hoses usually have a 7/16" hose although you might find a 3/8" high pressure fitting on really old regulators. In any case the high pressure fitting on the first stage will be marked "HP". You will also note the high presure port has a very tiny hole in the bottom, while the low pressure ports have large holes.

An important thing to understand is that you can easily overtighten a hose, stretch the threaeds and cause it to fail either immediaely, or worse, later in the water. Use a short wrench and choke way up on it, then only snug it up a bit past hand tight. With a new o-ring this might be 1/8 to 1/6th of a turn, with an old o-ring it might be only a 1/16" of a turn.

Also, it's a good idea to lubricate the o-ring. Silicone grease works, Christolube or Tribolube is better and in a pinch spit will get the job done.

 

[halocline]

It a 5000 psi hoses that goes to the gage.

Welcome to the forum. I'm not sure exactly where your leak is, but if it's at the end of the hose near the gauge, there is an additional part that can leak. It's a small spool that fits between the hose and the gauge. There are two small o-rings, one of each end of the spool. When you take the gauge off the old hose, you'll see it sticking out of either the gauge or the end of the hose. You'll have to pull it out, clean it, and change those o-rings as well, or you can buy a new one.

This spool leaks more often than the HP hose itself.

 

[DA Aquamaster]

There are three common types of HP spools. A short one a long one and one with a flange in the middle. All three have o-rings at both ends, but one some those o-rings can be very difficult to change, and the old spool can become corroded and if bad enough, it can be hard to clean.

A new HP spool is usually under $10 and your dive shop should install it for free.

As note above, when a spool leaks the gas will appear to come from the fitting itself. When the hose leaks, it usualy starts with a subtle airstone effect along a portion of the hose with small bubbles fizzing out and then gets progressively worse.

 

[josenandopr]

Thank you guy's.

 

[Couv]

Use a backup wrench:

If you are just moving a hose from one port to another (low pressure to low pressure, high pressure to high pressure) and leaving the other end as is, it’s a simple matter.

However, if you're completely changing out a hose, or removing the HP gauge or second stage regulator, a bit more caution is called for. NEVER just un-torque and re-torque a hose end to a plastic second stage or hp gauge without using two wrenches (one is called the backup wrench) ALWAYS hold the second stage or hp gauge fitting securely with one and then loosen the hose with the other. If you don't, you could very easily crack the housing of the unit you're working on.

See this page for a picture of a SPG with the spool Halo & DA are talking about.
http://www.scubatoys.com/store/detail.asp?PRODUCT_ID=DiveRite2NakedSPG

Here is a link to a page at ScubaToys where Joe & Larry give step by step instructions on replacing an SPG spool. Note the use of a backup wrench. The same technique can be used to replace a second stage. http://www.scubatoys.com/store/joelarry/hpspool.asp

Couv

Couv