Loose hose after dive.

[Txfirefighter4305]

The first time I thought it was a fluke. That maybe the tech that assembled it didn't torque it right. After my first day diving a brand new regulator, I discovered the hose going to my SPG/Console to be several turns loose at the 1st stage. To say this was a gut check holy crud moment what if it came off at depth is not doing it justice.

So after browsing SB and a call to the LDS Owner, I felt confident that tightening the hose myself would solve the problem. In addition, and with the blessing of the LDS I changed the side of the 1st the SPG hose was on.

Thursday, it happened again. Was tight before diving, but afterwards, it was loose. Not the several turns as before but loose enough to turn with your fingers.

What's going on here?

 

[lowviz]

1) Try clipping it off to a D-ring so that it faces you, the hose will 'learn' to stay that way with time. Could be that you are repeatedly twisting the console to make it face you while you read it.

2) Use your other hand to retrieve the console.

 

[redacted]

When you tightened the hose, how much torque did you apply?

 

[Txfirefighter4305]

About an eighth of a turn with a wrench after hand tight. Console has a swivel, and has even moved from my left side to my right side.

 

[redacted]

The Scubapro spec on that connection is 44 inch pounds which is fairly light. I usually do what you describe but I did put a torque wrench on it once just to check. As I recall, it took 1/8 to 1/4 turn after hand tight to hit the spec with new o-rings taking the 1/4 and older o-rings taking the 1/8. It can also be quite dependent on what you call "hand tight". I suggest you take it a bit beyond 1/8 turn closer to 1/4 and then keep a close eye on it.

BTW, the HP and the LP connections have the same torque spec, so I'm sure the spec is based on what should hold it tight as opposed to thread damage considerations. I disassemble most HP hoses for air travel and did have one come loose on me (actually, my wife's Mk20) once so I tend to go a little heavy on the estimated torque for that connection.

 

[Indian Valley Scuba]

I'm a little unclear here - the hose has a straight thread, which means there is no seal between the threads in the fitting. 100% of the seal with a straight thread is when the o-ring is compressed which only happens in the last fraction of a turn when tightening. Back it out a half turn and there is no seal, which means air will be blasting out of the threaded fitting. And of course you can only compress it so much, any more will actually distort the o-ring and you'll lose the seal.

So how was it that you finished the dive without a huge flow of gas coming out of the regulator if the hose was so loose?

 

[scubafanatic]

...not sure why you're only having this problem with ONE hose....I mean, if you don't know how to tighten up a hose, I'd assume you have this problem across more than one hose, so I'm wondering if the 1st-stage HP port threads have been damaged (overtightened or dross threaded at some point)?

 

[Txfirefighter4305]

I did not do the initial assembly. I purchased it new from my LDS where it was assembled. Nothing was loose at this point. Dove with it, then discovered the loose hose after returning home. Called LDS about it. Tightened the hose, 1/8 turn past finger tight. Sounds like I need to do 1/4 turn.

 

[knowone]

I hold my hose a foot from the end then screw it where it needs to go, usually o ring compressed metal to metal. I then grab the hose next to the end and twist it to check that the o ring is compressed and metal is to metal, which it always is. I then grab my spanner and tighten my hose until it is tight enough to not come loose as will come to you with practice.

It is IMPOSSIBLE to turn anything 1/8 to 1/4 turn after it is seated without damage even if it is not obviously visible.

One eighth of an INCH will suffice.

 

[redacted]

I hold my hose a foot from the end then screw it where it needs to go, usually o ring compressed metal to metal. I then grab the hose next to the end and twist it to check that the o ring is compressed and metal is to metal, which it always is. I then grab my spanner and tighten my hose until it is tight enough to not come loose as will come to you with practice.

It is IMPOSSIBLE to turn anything 1/8 to 1/4 turn after it is seated without damage even if it is not obviously visible.

One eighth of an INCH will suffice.

That hose connection should never go to a metal to metal stop point. All torque should be due to o-ring compression. When in doubt, use a torque wrench.