Should you use silicone grease when attaching hoses to First Stage?

[Rhone Man]

I do like the phrase "dynamic O-ring". Sounds like a very dorky superhero or unimaginative pro-wrestler.

 

[scott&sara]

Like I said, in operation is is static but during assemble it is by def dynamic....it moves past it's mating surface until it come to rest and if it moves it is subject to be deformed by that motion. Lubrication is to help prevent that deformation and to ensure it is not deformed when it reaches it final resting place. The only truly static Oring seal I can think of that is used in scuba is the oring in some camera housing, Ikelite for one.

you must be right... Parker doesn't know **** about o-ring design so maybe they should rewrite their design guide so that installation now makes an o-ring dynamic.

 

[redacted]

The only scuba O-rings you do not want to lube are those where the lube is subject to attract and attach dirt which may compromise function. That would be tank valve to 1st stage o-rings. Dynamic o-rings must be properly lubed or their failure will be accelerated. I usually lightly lube all others. If my christolube is not handy and I'm doing a quick fix on something like a static hose o-ring, a little spit works just fine to help it seat.

BTW, Parker Bros states "Examples of static o-rings are: a seal under a bolt head...plug or similar arrangement or, in general, the equivalent of a flat gasket."

 

[Saltwater Junky]

I am curious, by nature, and often reverse engineer to study how mechanical/electrical devices work. In turn, I learn how to repair them; however, I am slightly reluctant to do this with gear I entrust my life. This has been another valuable lesson without any hard knocks or having to replace any damaged gear. Glad I came across this thread.

 

[herman]

Sure they know what they are talking about: (From the afor mentioned manual Page 1-5)

"In a truly static seal, the mating gland parts are not subject
to relative movement (except for small thermal expansion
or separation by fl uid pressure), as contrasted from seals in
which one of the gland parts has movement relative to the
other. Examples of static seals are: a seal under a bolt head
or rivet, a seal at a pipe or tubing connection, a seal under a
cover plate, plug or similar arrangement or, in general, the
equivalent of a fl at gasket. Figure1-8 illustrates a typical
static seal.
Note: True static seals are generally quite rare. Vibrational
movement is present in vitrually all static applications."

 

[Kupu]

...well, I just rub a dab of spit around the o-ring before I screw the hose into the 1st stage when switching hoses. I guess spit is 02 compatible? A quick check of the o-ring to be sure it has no cracks and is still pliable vs stiff from age, replace if needed.

 

[matjo1]

you must be right... Parker doesn't know **** about o-ring design so maybe they should rewrite their design guide so that installation now makes an o-ring dynamic.

Chill dude.