There is a growing trend, a very dangerous growing trend in our area. I believe I know why it's occurring....though I will not point out what I believe is the cause in this blog. I will say it scares me to death. The trend I'm speaking of is the failure to properly maintain scuba cylinders.
Look, as dive center staff none of us want to be portrayed as villains harping on people about visual and hydro inspections but if cylinders are not properly tested and are subsequently filled, the filler is putting themselves at huge risk of injury and potentially death. Now, thankfully reputable dive shops do not fill said tanks, thus keeping that risk to a minimum but the risk remains for those who choose to fill regardless of the consequences. Pretty please don't give shop staff the stink eye for asking not to put them in a dangerous position, they just care about safety. Both yours and theirs. VIPs should be done by a qualified individual or shop. Yes there are places to buy stickers for visuals, if you aren't a qualified inspector but mark your tanks with these stickers you are potentially putting someone else at risk when they fill your tank.
Ever have a burst disc blow whilst you are standing right next to a tank? I have experienced several over the years, and while this is really minute compared to what CAN happen. it's certainly a 'pee your pants' moment. Even shops have maintenance they need to undertake. I myself for example have changed a few fill whips at our store due to use over time. I had one whip suddenly blow at the fitting, the metal end hitting me square in the ribs (OUCH!), that was a painful and almost very dangerous (as it almost hit my head) lesson I learned. This is also why our shop staff are the ones who hook up your cylinders. Tanks can and do explode. It doesn't happen often, but not oxygen cleaning the cylinder and VALVE before getting oxygen or partial pressure fills puts you at huge risk. Do you really trust that the o2 cylinder you bought off that forum is o2 clean just because the prior owner said so? Want to fill it yourself and see? I had a customer bring in a bottle once in said condition, empty, and ready to fill. I asked if I could just check the valve first before filling and LOW AND BEHOLD: silicone lubricant on the valve threads! Needless to say, a cleaning was needed but it saved me and the square block from a near-nuclear explosion as I stood nearly dumbfounded next to no less than 7 cylinders filled with pure oxygen.
Here are the general recommendations I make to our customers:
- VIP yearly or as needed [if a tank becomes filled with water or (god forbid) oil somehow. Yes this happens too, probably more than you might think. In this case an immediate VIP, and possibly more is required in my book.]
Oil mixed with water that came out of a cylinder needing VIP, in turn obviously requiring cleaning and tumbling.
- Hydro every five years.
- At hydro, burst disc and valve rebuild is suggested. It stinks to have to replace a burst disc or an internal valve seat when you JUST filled your set of double 104's....worse when they just came back fresh from hydro and no burst disc replacement was made. No one likes paying for gas twice.
- Tumbling, as needed.
- Cleanings are done as required (every shop is a little different, some demand a fresh cleaning at every VIP, some at Hydro. Ask your LDS for their requirements.) If you don't know the date of the last oxygen cleaning and you need an oxygen or partial pressure fill, it's probably a safe bet you need one. Don't forget to clean the valve also, otherwise you really don't have an oxygen clean cylinder.
Now go forth and have some fun and safe dives!