SCUBA Tank Markings – VIP and Hydrostat
On a recent dive at Devil’s Den Spring, I had the luxury of arriving earlier than the rest of our NAS JAX Skin Scuba Diving Club for an Earth Day dive, and got to spend a bit of time with one of the techs who explained all the SCUBA tank VIP markings and other markings on the tank. I’m pretty sure this was all explained to me… wayyyyy back when I got certified, but I had not looked really closely at anything but the annual stickers lately.
First of all, there is the tank VIP sticker from the annual visual inspection. On the left, JUN is starred out – and on the right, 17 is starred out, so, the last annual VIP on this tank was in June of 2017, and it is good for one year. Whenever you are on a dive boat or renting tanks, it’s a good idea to glance at this sticker and make sure the tank you are about to use is in date. There’s plenty of other information on the sticker; where the testing was conducted, their telephone number. The Visual Plus is an additional technology to detect cracks. Very interesting reading. Without going deep into technical terms, this test can provide an additional layer of non-human detection of flaws.
Next, we looked at all those punched – in numbers and letters in great detail. I can muddle my way through a VIN hull number on a boat, and on a SCUBA tank, there is just as much useful information. If you see “DOT,” that stands for Department of Transportation, and that means the tank meets United States specifications. 3AL stands for three-gauge aluminum. “LUXFER” is the name of the company who manufactured the tank. This tank below specifically writes out the “3000” service pressure (s.p.i.g.).
Then you will see a number – the month it was manufactured – “A” – an inspection code symbol – and “M2 07” on the tank above, because it was made in February of the year 2007. The tank below shows a “03 A 00” so it was manufactured in March, 2000. To the right of all that, you can see “S80” which is Luxfer’s model and part number for this tank; this one is a standard 80 cubic foot tank. Some might say “SO 80” meaning the same. Somewhere near that manufacture date, on this tank they are above, are the hydrostatic test dates. This one was “hydrostatted” in 2005, 2010, and 2015. It’s next hydrostat will be due in 2020. Somewhere will be an eight-figure letters and numbers serial number.
If you have only a moment or two between meeting your rental tank and strapping it on your back; it would be good to quickly verify three things – month and year of most recent VIP, and year of most recent hydrostat.
For Nitrox tanks; the VIP sticker also will have an “02 clean” designation. This means there have been additional cleaning procedures compatible with partial pressure blending – 40% or lower nitrox mixtures. On those tanks, you might see green and yellow Nitrox stickers, and some type of tape near the cylinder neck with the mixture % hand written.
With some upcoming shore dives planned, it’s time for all our tanks to have their annuals at Diver’s Supply Jacksonville. You never know when you’ll have a chance to go dive, and if you have your tanks up-to-date; you are always ready for the impromptu!
Two Pepto-Dismal-Pink tanks given to me by a friend. Straight to Diver’s Supply Jacksonville, they go! I can’t do anything about the color of these 63’s, (63 cubic feet) but I can make sure they are seaworthy. The black tanks in back were once visually inspected in Guam. We asked that the sentimental Guam stickers be left in place, and new stickers affixed elsewhere.
Waiting for our tanks to be “admitted” for service, I took a moment to look at the markings on the new shiny aluminum and steel tanks. Oooooo!
The resident fish at Diver’s Supply Jacksonville. He oversees the checkout.
What do you think – in a breakdown of whether it’s better to rent or own tanks – where is the “break-even” point?
Resources:
Force-E Scuba Centers – Your SCUBA Tank Is A VIP – Don’t Forget Its Annual Inspection
Luxfer’s Scuba Cylinder Visual Inspection Guide – Interesting photos of tanks that would not pass inspection, and descriptions of using dental mirrors to detect anomalies.
