You might find information in these two threads useful:
O-rings for Divers
Scuba Cylinder Valve Installation
O-rings for Divers
Scuba Cylinder Valve Installation
O-Rings 101, Understand the seal-eology
- Thread starter The Chairman
- Start date
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OP
Congratulations for the post. Lot's of interesting info.
I have a question: How "probable" a harder than the original o-ring is to cause a flooding in a camera casing?
Here is the story: The housing of my camera (Meikon) had two very soft white o-rings (I guess Buna), one for the body of the case and one for the back cover. Fortunately it came with a spare one as well. During my first trip that I had that case, after only few dives (6 or so) and several openings (to try things out with my new rig etc) I fount that the o-ring of the back cover had a small piece (about 2mm - 1/16 of an inch in diameter) chipped off its' surface - like somebody tried to peel a slice out of its' surface with a razor or something. Luckily I saw it before diving and I had the spare ring that came with the housing with me - so it caused no real problems.
The original o-ring had not been removed from its' groove since I bought the housing (it was pre-installed) and overly to that point it was treated very carefully by me. I think what happened was that as the case was closing the o-ring got stuck between the covers and they sliced it like a pair of scissors would. A bit difficult because the o-ring sits nicely in a groove and everything has rounded edges etc but I can't think of anything else causing this.
Anyway back home I tried to find replacement o-ring and all I could find was a Viton one. Same dimensions but quite harder (and much more expensive) than the original one. I took it to give it a try.
To try it, I put the case for several hours in water and bring it to a dive without camera inside etc and all seemed good so I decided to go with the harder o-ring. I like the feeling of it - it feels much stronger and robust than the original one. I have done 10 dives or so with the harder o-ring, down to 80feet/25meters or so (I don't plan to dive deeper than 100feet/30meters anytime soon) and so far it performs well.
Do you think it is safe to keep using it???
Thanks
I have a question: How "probable" a harder than the original o-ring is to cause a flooding in a camera casing?
Here is the story: The housing of my camera (Meikon) had two very soft white o-rings (I guess Buna), one for the body of the case and one for the back cover. Fortunately it came with a spare one as well. During my first trip that I had that case, after only few dives (6 or so) and several openings (to try things out with my new rig etc) I fount that the o-ring of the back cover had a small piece (about 2mm - 1/16 of an inch in diameter) chipped off its' surface - like somebody tried to peel a slice out of its' surface with a razor or something. Luckily I saw it before diving and I had the spare ring that came with the housing with me - so it caused no real problems.
The original o-ring had not been removed from its' groove since I bought the housing (it was pre-installed) and overly to that point it was treated very carefully by me. I think what happened was that as the case was closing the o-ring got stuck between the covers and they sliced it like a pair of scissors would. A bit difficult because the o-ring sits nicely in a groove and everything has rounded edges etc but I can't think of anything else causing this.
Anyway back home I tried to find replacement o-ring and all I could find was a Viton one. Same dimensions but quite harder (and much more expensive) than the original one. I took it to give it a try.
To try it, I put the case for several hours in water and bring it to a dive without camera inside etc and all seemed good so I decided to go with the harder o-ring. I like the feeling of it - it feels much stronger and robust than the original one. I have done 10 dives or so with the harder o-ring, down to 80feet/25meters or so (I don't plan to dive deeper than 100feet/30meters anytime soon) and so far it performs well.
Do you think it is safe to keep using it???
Thanks
OP
I haven't been able to see the set-up, so it's impossible to hazard a guess. It would depend on how the o-ring seals, the rigidity of the housing (flex?) and the difference in the pliability of the o-rings. So really, I don't know. However, you did it right by taking an empty housing for a dive first. If it were mine, I'd keep using it like that, but would try contacting the maker of the housing to ask them and/or order the right seals.
BuceoVerde
Registered
@The Chairman
Really good posting here and follow-up links. The info here goes really well with the regulator course.
I ordered my 010 O-rings and a few other reg maintenance tools.
I think the best thing I learned from the reg course is that I now understand how to adjust my regs and I can do it with just a bucket of water, an IP gauge and some common tools.
Thanks again for the regulator course!!! Well done!!!
Really good posting here and follow-up links. The info here goes really well with the regulator course.
I ordered my 010 O-rings and a few other reg maintenance tools.
I think the best thing I learned from the reg course is that I now understand how to adjust my regs and I can do it with just a bucket of water, an IP gauge and some common tools.
Thanks again for the regulator course!!! Well done!!!
Hi, I've seen many times that the thread in hoses and adapters is marked as UNF and not as NPS. Is UNF the same as NPS ?
OP
I've never seen UNF used in describing pipe threads. UNF is equivalent to NF and UNC is equivalent to NC.
OP
I believe the use of UNF to be in error there. If you read the Wiki page on NPT, you won't find a mention of UNC or UNF: National pipe thread - Wikipedia
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