SCUBA Tank (Cylinders) FAQ

Products - Gas - Cylinders

FAQ ABOUT SCUBA TANKS
Because there are so many choices, even experienced divers can become confused by the latest features and diving applications of scuba tanks. If that's you, then you might benefit from reading the most popular article on our website. How to Select a SCUBA Tank is a very detailed whitepaper focused on helping divers choose the best SCUBA tank for their specific needs and styles of diving.

We strongly recommend purchasing our cylinders ONLY for use in North America and the Caribbean. All our cylinders have United States DOT and Canadian CTC testing and crown markings along with Imperial neck thread forms. The cylinders are NOT marked appropriately for use in Australia and New Zealand. Testing and marking specifications, neck thread forms, and over pressure relief device requirements in many other areas of the globe (especially Europe) are different than North American standards.

In the US and Canada, SCUBA Tanks must be hydrostatically tested every five years (60 months) and we always ship cylinders with the absolute most current test date available to us. Most cylinders have a factory test date less than 12 months old. Less popular sizes of cylinders may have a slightly older factory test date as these are manufactured infrequently.

Yes, they will be assembled and ready to fill, if shipped via ground service within the continental United States. Transportation security and customs regulations require cylinders that ship via air transport to be obviously empty and easily inspected. Effectively that means the cylinder and valve cannot be assembled if shipping to an international address (including Canada) or via any expedited shipping method.

If you are arranging to have your cylinders delivered to a third-party package forwarder for subsequent handling, you may wish to request on your order that we do NOT assemble your cylinders and valves.

All cylinders and valves sold by us, that we describe as Nitrox Ready, are oxygen clean and oxygen compatible from the supplier. Based on oxygen handing best practices, Dive Gear Express does not use any form of lubricant during valve installation. That means all Nitrox Ready SCUBA tanks sold and assembled by Dive Gear Express, prior to initial use, are oxygen clean and oxygen compatible from the supplier; we have done nothing to change that condition.

In rare cases, a shop will insist on some form of after-market "cleaning" before agreeing to fill a tank not sold by them. They have that right, but we want you to know that no such service can make a new empty cylinder and valve from Dive Gear Express any more oxygen clean or more oxygen compatible.

Every tank we sell is inspected by us immediately prior to shipment and all our technicians are PSI-PCI certified to perform such inspections. If the cylinder is ordered with valve and VIP, we include our shop evidence of inspection 3" X 6" month and year dated decal (aka "VIP sticker") that clearly indicates "Nitrox Ready" in large yellow letters on a green background. However, If the cylinder is ordered with the "No Valve / No VIP" option then our evidence of inspection decal is not included even though the cylinder itself is always inspected.

No, our tanks don't include the Large Nitrox Tank Wrap Decal used to indicate gas contents. If the cylinder is ordered with valve and VIP, we include our shop evidence of inspection month and year dated decal (aka "VIP sticker") that clearly indicates "Nitrox Ready". However, the VIP sticker is not used to indicate the gas contents and Nitrox Ready does not mean there is actually Nitrox gas in the tank. The tank wrap can be ordered separately, however please read our TekTip titled Do I really need that big NITROX wrap decal on my tank?
The CCR Cylinders and Valves in our Rebreather category have differences in their configuration than those in our Gas-Tanks category. The cylinders and valves themselves are physically the same in both categories; equally oxygen compatible and oxygen clean. However, the CCR cylinder selections are only appropriate for rebreather in-board mounting and include options to add Oxygen/Diluent contents decals. Cylinders configured for CCR will ship with the VIP decal unaffixed so it can be later applied to the cylinder wall in a location unobstructed by rebreather tank mounting systems. The CCR valve configuration options include our specialized versions typically only seen on rebreathers, along with options to select knob color and do not include a No Valve/No VIP option. Rebreathers only use DIN regulator fittings, so the included valve accessories for CCR are a threaded dust plug rather than a vinyl cap and do not include a DIN-to-Yoke insert adapter.
Yes you can, but we don't recommend it for two reasons. We buy the cylinders with a valve at a discounted bundle price and we pass that discount on to you. If you wish to purchase the cylinder without the valve then the reduction in price we can offer is a meager $15.00 considering the price of the valve when sold separately. While we always inspect the cylinder before shipping, if there is no valve then we can't provide a VIP decal because it only applies to both the cylinder and valve together. It only makes sense to purchase without valve when you have absolutely no use for the valve and don't need the VIP decal.

During the initial use of hot-dip galvanized (HDG) tanks, they develop a streaked and mottled appearance although over time that becomes more uniform. Do NOT attempt to remove the white, grey, or black looking discoloration, it is normal and part of the protection provided by the zinc metal coating.

Hot-dip galvanizing (HDG) on Faber brand steel tanks offers the best possible durability and corrosion protection. However, the cosmetic appearance of the thick hot-dipped galvanized finish is NOT as perfect and consistent as a painted finish over hot-spray galvanizing. We feel cosmetics is unimportant in relation to durability and only offer HDG finish when available for steel tanks.

No, but don't worry - we will completely seal your cylinder so that it will arrive with a factory oxygen clean interior. We sometimes receive this question based on the mistaken belief that filling the cylinder is necessary to protect the interior from contamination or moisture, however the US Department of Transportation says any SCUBA tank containing compressed gas can not legally be shipped via ordinary parcel delivery services.

If the tank was assembled by Dive Gear Express with our Nitrox Ready evidence of inspection decal (aka "VIP sticker"), then your oxygen clean and oxygen compatible tank is ready to fill without further preparation. Although local dive shop fill policies vary, there should be no safety related reason for objecting to initially filling the empty SCUBA tank with oxygen compatible grade Air or Nitrox. However, shops often enforce training agency requirements or community practices for labeling, which may require additional specific gas contents or MOD decals be affixed to the tank.

YES, you can take empty SCUBA tanks on airplanes. However, the Transportation Security Administration (TSA) has some very specific inspection conditions for tanks to be permitted in aircraft. For details, please see our TekTip Advice for Flying with SCUBA tanks.

Dive shops following best practices will not fill cylinders marked as being oxygen clean with ordinary CGA grade "E" compressed gases typical of most dive shop fill stations. In this case, the fill station operator can simply remove our Nitrox Ready decal and replace it with one they prefer. If you wish to order any of our tanks intending to use them strictly for air only, then upon request we can substitute an "Air Only" black and white version of our shop evidence of inspection decal (aka "VIP Sticker").

Quick Reference for 232 bar cylinders:
18L (141 ft3) and 15L (117 ft3) = 8-inch (large);
12L (95 ft3), and 10L (78 ft3) = 7-inch (standard);
7L (54 ft3) and 5L (39 ft3) = 5-inch (small).

These are simple approximations, for more detailed explanations please read our article Metric vs Imperial SCUBA Cylinder Sizes.