Scuba Tank Size Chart
Samuel Johnson March 7th, 2022 Posted In: Articles Tags: SCUBA
Scuba Tank Size Chart
SCUBA cylinders or SCUBA tanks are used to hold compressed air or a mix of gasses that a diver can breathe while underwater. What does SCUBA stand for? Find out! There are many different sizes of SCUBA tanks available from small rescue tanks to large steel cylinders. However, there are only a few manufacturers of these tanks.
SCUBA Tank Sizes
The best known manufacturers of SCUBA tank cylinders are Catalina, Faber, Luxfer, Metal Impact, and the now closed Pressed Steel Tank Co (PST). Cylinder specifications are regulated by the Department of Transportation (DOT) in the U.S., and various regulatory entities internationally like Transport Canada (TC). Here are some SCUBA cylinders by various manufacturers and their related specifications:
SCUBA Cylinder Size Chart (In order by height or length)
| Manufacturer | Model #(HP = HighPressure) | Capacity (Volume in Cu Ft) | Length/Height (Inches) | Diameter (Inches) | Weight (When Empty in lbs) |
| Metal Impact | S06 | 6.0 | 11.1 | 3.20 | 2.5 |
| SpareAir | 300PK | 3.0 | 13.4 | 2.25 | 2.2 |
| Metal Impact | S40 | 40.0 | 14.6 | 5.25 | 15.3 |
| Catalina | S19 | 19.0 | 17.7 | 4.38 | 7.8 |
| Faber (Steel) | HP80 | 80.0 | 20.9 | 7.24 | 28.6 |
| Catalina | S80 | 77.5 | 25.9 | 7.25 | 31.3 |
| Luxfer | S106W (HP) | 105.0 | 26.1 | 7.40 | 33.8 |
| Metal Impact | S100 | 98.8 | 26.2 | 8.00 | 41.1 |
| Faber (Steel) | HP120 | 120.0 | 29.1 | 7.25 | 39.2 |
Differences between U.S. and international standards, when it comes to SCUBA tanks, boil down to imperial versus metric measurements. The Department of Transportation (DOT) in the U.S. uses Pounds per Square Inch (PSI) instead of Bars in reference to pressure. Inches (In) instead of millimeters(Mm), Cubic Feet (Cu Ft) versus liters (L), and so on. Most of the SCUBA cylinders you will see are rated up to 3000 PSI. There are times when a tank can be overfilled, but this is complicated and depends on many conditions.
SCUBA Tank Safety
Safety is the priority when dealing with compressed gasses. Also check out these SCUBA Diving Safety Rules. There are High Pressure (HP) tanks, like the Luxfer S106W rated for 4350 PSI, and Low Pressure (LP) tanks as well. Air fill stations like those found at Dive shops are typically geared towards 3000 PSI tanks and the compressor may not be able to fill High Pressure (HP) or non standard tanks to capacity.
1 Bar or 14.5 PSI, is roughly equal to the average atmospheric pressure of the Earth at sea level.
Which SCUBA cylinder is right for you depends a great deal on personal preference as well as the location, depth, and length of your dive. Looking at the table above you can see the larger tanks become quite heavy when empty and even heavier when filled with compressed air! An AL80 SCUBA cylinder, which is an aluminum 80 cubic foot tank, can increase in weight by over six pounds when filled. Notice that a steel 80 cubic foot capacity tank like the Faber HP80 weighs less empty than a comparable aluminum version and is almost five inches smaller!
SCUBA Tank Size Chart Continued
Total weight can become an issue when you factor in other SCUBA gear. Check out this blog “How Heavy is a SCUBA Tank & Gear?” for more info. Steel cylinders are stronger and manufacturers can use less material to make them when compared to an aluminum tank of the same capacity. Disadvantages of steel tanks include corrosion potential and increased cost. One of the most commonly used rental and training cylinders at SCUBA dive shops are the aluminum (AL) 80 cubic foot tanks.
The length of these tanks range in the area of 21-26 inches and are generally well handled by beginners and novices. A beginner SCUBA course will cover much of the basics and science behind compressed air cylinders and how to safely operate them. You may also be interested in this blog on the reasons to wear a wetsuit. One will often see SCUBA cylinders referred to by their capacity rather than their length or actual size.
In fact, SCUBA tanks come stamped at the top with regulatory information that includes the metal type, manufacturer, original hydrostatic test date, and capacity at service pressure. Divers can customize their SCUBA loadout with multiple tanks, different yokes and adaptors, and even take along an emergency SpareAir container.
SCUBA Tank Sizes: Summing It Up
There are a wide variety of SCUBA tanks in different sizes, metals, and capacities. One could stop by a local SCUBA shop to examine some available options and compare the size and weight. Generally the higher the capacity, the larger and heavier the cylinder.
SCUBA tanks do have a limited lifetime depending on maintenance and general care. They must undergo hydrostatic testing and visual inspections often to prevent accidents and underwater emergencies. The chart shown earlier helps compare some of the major differences between SCUBA tanks available on the market today.
FAQ: SCUBA Tank Size Chart & Cylinder Specifications
Before we get into the questions, here’s a quick overview: SCUBA tanks come in a wide range of sizes, materials, and pressure ratings. Understanding how tank capacity, weight, and dimensions vary can help divers choose the right cylinder for their dive style, depth, and comfort level. These FAQs expand on the most common questions divers search for when comparing SCUBA tank sizes!
1. What are the most common SCUBA tank sizes?
The most commonly used SCUBA tank is the Aluminum 80 (AL80), which holds about 77–80 cubic feet of air and measures around 25–26 inches in length. Other popular sizes include smaller rescue cylinders like 6–19 cu ft tanks and larger steel cylinders such as HP80, HP100, and HP120.
2. How do SCUBA tank sizes differ between manufacturers?
Manufacturers like Catalina, Faber, Luxfer, and Metal Impact produce tanks with similar capacities but different weights, lengths, and diameters. For example, a steel HP80 from Faber is shorter and lighter than an aluminum S80 from Catalina, even though both hold roughly the same volume of air.
3. What’s the difference between steel and aluminum SCUBA tanks?
Steel tanks are stronger, allowing manufacturers to use less material, which makes them lighter and often smaller than aluminum tanks of the same capacity. Aluminum tanks are more affordable and widely used for training and rentals, but they tend to be bulkier and more buoyant at the end of a dive.
4. How is SCUBA tank capacity measured?
In the U.S., tank capacity is measured in cubic feet (cu ft), which represents the volume of compressed gas the tank can hold at its rated service pressure. Internationally, capacity is often listed in liters (L). Pressure ratings also differ: PSI is used in the U.S., while bars are used internationally.
5. Why do some SCUBA tanks weigh more when filled?
Compressed air adds weight. An AL80, for example, can gain more than six pounds when filled to its service pressure. Larger tanks or high‑pressure cylinders hold more air, which increases their total weight even further.
6. What is the difference between high‑pressure (HP) and low‑pressure (LP) SCUBA tanks?
HP tanks operate at higher service pressures (often 3442–4350 PSI), allowing them to store more air in a smaller size. LP tanks operate at lower pressures (typically around 2400–2640 PSI). Not all dive shops can fill HP tanks to their full capacity, so availability of proper fills can influence your choice.
7. How do I choose the right SCUBA tank size for my dive?
Your ideal tank depends on your air consumption rate, dive depth, dive duration, and comfort with weight and buoyancy. Larger tanks offer more breathing time but are heavier. Smaller tanks are easier to handle but hold less air. Many beginners start with an AL80 because it offers a balanced mix of capacity and manageability.
8. Do SCUBA tanks expire or have a lifespan?
Yes. SCUBA tanks require regular visual inspections and hydrostatic testing to remain certified for use. With proper care, steel tanks can last decades, while aluminum tanks may have a shorter lifespan due to metal fatigue and corrosion risks.
