Nylon 6 6 and Nitrox stickers???

[WhatAnIdea]

Hello,

I just left my LDS after recieving a blast over nylon 6 6 in the sherwood tank valves and not having Nitrox bands on the tank. I'd like to discuss these two issues and hear what other people have to say.

So here's my story. I have several tanks all of which I have owned for approximately three to five years. Every year I have the tanks VIP with the O2 plus for nitrox service. In all that time no dive shop has ever said I had to have nitrox stickers on the tanks and at no time has any shop told me the tank valves contained materials that were not O2 compatible. I should mention that over the past five years two different dive shops have serviced these tanks... tonights reading of the riot act came from a third dive shop.

Anyway I was shown the tank valve seat assembly in particular the green flakey stuff on the threads and told that this Nylon 6 6 which flakes off had to be removed. I was also told to Google Nylon 6 6 to get an understanding of the problem. So I did as instructed and an article on Nylon 6 6 in tank valves. Now if I read it correctly the Nylon 6 6 isn't the green lubricant on the threads but the actual seat material. If that's the case it seems the guy at the LDS might be confused... if not then I am confused for sure.

Anyway the long and the short of this is I'm all for doing the right thing but I want to be sure I know what the right thing is. Does removing the greenish lubricant on the threads of the tank valve seat assembly remove the Nylon 6 6 or does the seat assembly have to be replaced?

Next issue... Nitrox stickers. What is the deal with these stickers? Are they required and if so by whom? I quetion the importance of these stickers... It's not like the VIP sticker which informs the facility filling the tank that this tank is safe. Having the Nitrox sticker can also be missleading as the tank could have air... or it could have any concentration of O2 all the way up to 100% O2. So what is the importance of these stickers? Seems like a cash grab too me. If someone could provide me with a strong arguement to support the use of these stickers that would be great.

Many thanks to all those who reply.

 

[jtivat]

The green stuff on the valves is Teflon an is safe for use with O2 the guy is an idiot!

There is no law requiring nitrox sticker but some shops do, I would find another shop.

 

[padiscubapro]

Hello,

I just left my LDS after recieving a blast over nylon 6 6 in the sherwood tank valves and not having Nitrox bands on the tank. I'd like to discuss these two issues and hear what other people have to say.

So here's my story. I have several tanks all of which I have owned for approximately three to five years. Every year I have the tanks VIP with the O2 plus for nitrox service. In all that time no dive shop has ever said I had to have nitrox stickers on the tanks and at no time has any shop told me the tank valves contained materials that were not O2 compatible. I should mention that over the past five years two different dive shops have serviced these tanks... tonights reading of the riot act came from a third dive shop.

Anyway I was shown the tank valve seat assembly in particular the green flakey stuff on the threads and told that this Nylon 6 6 which flakes off had to be removed. I was also told to Google Nylon 6 6 to get an understanding of the problem. So I did as instructed and an article on Nylon 6 6 in tank valves. Now if I read it correctly the Nylon 6 6 isn't the green lubricant on the threads but the actual seat material. If that's the case it seems the guy at the LDS might be confused... if not then I am confused for sure.

Anyway the long and the short of this is I'm all for doing the right thing but I want to be sure I know what the right thing is. Does removing the greenish lubricant on the threads of the tank valve seat assembly remove the Nylon 6 6 or does the seat assembly have to be replaced?

Next issue... Nitrox stickers. What is the deal with these stickers? Are they required and if so by whom? I quetion the importance of these stickers... It's not like the VIP sticker which informs the facility filling the tank that this tank is safe. Having the Nitrox sticker can also be missleading as the tank could have air... or it could have any concentration of O2 all the way up to 100% O2. So what is the importance of these stickers? Seems like a cash grab too me. If someone could provide me with a strong arguement to support the use of these stickers that would be great.

Many thanks to all those who reply.

The green stuff is usually a lubricant and is compatible.. the nitrox compatible valve seats direct from sherwoord were green (havent ordered any in a long time so not sure if they still are) but there were alternate sources that had non nitrox compatible materials.. with careful inspection a good technician should be able to tell the difference..
A full valve rebuild and cleaning should be done every year, this means replacing this seat anyway.. contaminents build up within the valve and its important to clean them especially when partial pressure blending is involved.. Clean/rebuild of a valve is much more important than o2 cleaning of a cylinder (unless you know the cylinder has contamination) since the valve surfaces are poor heat sinks.. an o2 cleaning a rebuild should run around $25 (or so) a year not a big expense for a safety critical piece of equipment..

the requirement to use or not to use a tank wrap really depends on the shops insurance policy.. most policies dictate that they follow published standards and aganecy guidelines.. Most agencies require proper identification on the tanks - and these guidlines generally mention NOAA rules which mean a tank wrap or specific painted requirements.. if there is an accident and the standards weren't followed the insurance carrier has a way out..


BTW there are currently no generally accepted protocols for tanks with gases other than nitrox.. like trimix, so if a tanks is marked for trimix there is no wrap/lettering requirement in the US (some countries do have requirements for all breathing gas cylinders).. generally cylinders labeled for trimx have a place to fill in the gases, technically these cylinders can have nitrox in them as long as the label is filled out correctly..

Alot of people may not like tank wraps but if it is required of their affiliation and they don't require it I would be thinking what else don't they follow and go elsewhere..

 

[knotical]

Not addressing the technical issues, but rather attitudes:

If they read you (the customer) the riot act, I'd get my gear back and never darken their doorstep again. Or at least talk to the manager.

If instead they were politely pointing out their concerns, this could be an opportunity for you and them to help educate each other. Share with them what you learn here and in your internet searches.

 

[rstofer]

The tank wrap is to warn OTHER divers that the tank they are about to grab (but don't own) may contain a mixture other than air. Every one of my tanks is wrapped (14 of them I think) although only 6 actually contain a mixture other than air.

I like the Voodoo Gas stickers better but I doubt an LDS will find them acceptable: Tank stickers

The stickers are there for a purpose. I don't consider them a "cash grab" by the LDS.

Richard

 

[Meng_Tze]

It is best if the content of a scuba tank is marked to indicate the content. There is no law about this. Definitely not for 'Nitrox wraps'.

Some of my tanks (O2, 32m) have a standard marking of MOD . None of my 'multi purpose' tanks have any markings but my initials. These tanks get a piece of duck tape with MOD written on it when used. It is for my own benefit. If some idiot would decide to take one of my tanks and dive it, they are at their own risk. It clearly has my initials on it, thus it is not theirs. It also has a marking on there (content and MOD). If they do not understand that.... oh well.

 

[Doc Harry]

I used tags from IANTD to mark my cylinders. The tags are kinda like a luggage name tag. My LDS wouldn't fill my cylidners without some kind of marking, but they agreed that the tank wraps were not required for their purposes.

 

[paddler3d]

I like the Voodoo Gas stickers better but I doubt an LDS will find them acceptable: Tank stickers

Richard

I used to have the Voodoo Gas stickers on my tanks, frankly to protect some other idiot on the boat. I took them off because they became a PITA.

I had issues with one dive shop and issues with Other divers.

90% of the time I dive 21%. My little MOD stickers reflect that.

I've found on boats other divers see the Voodoo sticker, and don't see the humor, and start giving me lectures on O2 clean and Nitrox and bunch of crap. Typically these are the divers I see kicking up the silt in/on/around the wreck and scarring the wildlife away.

I had an issue with one dive shop, Divers Direct, who refused to fill my tanks with 21%, air, despite the fact they were marked with 21%, air, because that is what I had been diving. They would fill them if they could VIP them and remove the stickers. I finally got the manager on the floor and she started to explain it was their insurance carrier that made them follow these guide lines. When I suggested I can open the valves and bleed the tank, the manager then said she would have to VIP the tank because it was empty. Needless to say I left with my tanks and I don't go there. I just had to wait for Ocean Divers to open up the next morning.

Oddly the guy at Ocean Divers looked at my tanks, asked if I wanted Nitrox or Air, asked what I had in there, took a tester and checked, filled my tanks and told me what wrecks would be good that day.

Morale of the story is, mark your tanks so you know what is in them, make sure your dive buddies know what is in them, and keep the advertisement of what is in your tanks to a minimal. It makes for a much more enjoyable diving experience.

BTW, the way I found to get around having some idiot grab my tank is all my tanks are DIN. My experience is someone who is diving DIN is typically more competent than someone who is not. Sorry to the Yoke folks, this is just my experience. Aside the yoke reg won't work on the DIN valve and they eventually figure that one out. It takes a moment though and lets me get in my little secret chuckle!