Catalina Cylinders vs Luxfer
S30 vs L6X S40 P3403V Scuba Cylinder
Cylinder choice: capacity, handling and valve fit.
Catalina Cylinders
LuxferScores are our editorial opinion of these models, based on features, suitability and ownership trade-offs—not hands-on test results. How we chose →
We’d pick the L6X S40 P3403V Scuba Cylinder.
Our pick is Luxfer L6X S40 P3403V Scuba Cylinder. We like this 5.7-litre option when an M25-threaded cylinder fits the planned setup.
Which one suits you?
Catalina Cylinders S30
We like the shorter 4.3-litre option when a smaller cylinder is the deliberate requirement. The smaller gas capacity has to meet the plan; compactness cannot decide that for you.
Get to know this model →Luxfer L6X S40 P3403V Scuba Cylinder
Product photo coming soon.
We like this 5.7-litre option when an M25-threaded cylinder fits the planned setup. Confirm the valve and approval for the exact cylinder supplied.
Get to know this model →Specifications side by side
The details that matter, side by side. “Check with the brand” means we have not confirmed that detail.
| Detail | Catalina Cylinders S30 | Luxfer L6X S40 P3403V Scuba Cylinder |
|---|---|---|
| Water / air capacityCheck with the brand | 4.3 L / 30 cu ft | Check with the brand |
| Service pressure | 3000 psi / 207 bar | 207 bar |
| Diameter × cylinder lengthCheck with the brand | 133.4 × 505 mm | Check with the brand |
| Cylinder weight | 6.2 kg | 7.2 kg |
| Buoyancy: full / 500 psi / emptyCheck with the brand | -2.4 / -0.7 / -0.2 lb | Check with the brand |
| Water capacityCheck with the brand | Check with the brand | 5.7 L |
| DimensionsCheck with the brand | Check with the brand | 140 × 585 mm |
| Neck threadCheck with the brand | Check with the brand | M25 |
Showing all 8 specification rows.
What the differences mean when you buy
Capacity and service pressure
Catalina Cylinders S30
- Water / air capacity
- 4.3 L / 30 cu ft
- Service pressure
- 3000 psi / 207 bar
Luxfer L6X S40 P3403V Scuba Cylinder
- Water capacity
- 5.7 L
- Service pressure
- 207 bar
Keep internal water volume, nominal gas capacity and service pressure distinct. A model name can be a nominal designation rather than its precise published air volume. Compare the stated pressure basis and use a properly established gas plan; capacity differences cannot be converted into universal minutes of diving or emergency ascent time.
Dimensions, weight and mounting
Catalina Cylinders S30
- Diameter × cylinder length
- 133.4 × 505 mm
- Cylinder weight
- 6.2 kg
Luxfer L6X S40 P3403V Scuba Cylinder
- Dimensions
- 140 × 585 mm
- Cylinder weight
- 7.2 kg
Check cylinder-body dimensions against compatible mounting equipment and the full valve arrangement. A lower-capacity cylinder may be longer but narrower than another. Listed cylinder weight is not necessarily the ready-to-use assembled weight with gas, valve and accessories. Verify what each measurement includes before planning transport or fitting.
Buoyancy through the dive
Catalina Cylinders S30
- Buoyancy: full / 500 psi / empty
- -2.4 / -0.7 / -0.2 lb
Luxfer L6X S40 P3403V Scuba Cylinder
Ask the brand about this detail before ordering.
Read full, partially depleted and empty buoyancy separately, preserving the sign and the stated measurement conditions. Cylinders with equal diameter or pressure can behave differently as gas is used. Use these figures as input to qualified equipment assessment rather than a direct ballast prescription or a reason to copy another diver’s setup.
A closer look at both
S30
S30 combines 30 cu ft air capacity with a 4.3-litre internal volume. At 133.4 mm across and 505 mm long, it sits between Catalina’s narrow S19 and longer S40. The listed 6.2 kg cylinder weight makes transport and mounting more substantial than its compact capacity suggests.
What we like
We like the shorter 4.3-litre option when a smaller cylinder is the deliberate requirement.
What would make us think twice
The smaller gas capacity has to meet the plan; compactness cannot decide that for you.
More about the S30 →L6X S40 P3403V Scuba Cylinder
L6X S40 P3403V Scuba Cylinder is an aluminium cylinder with 5.7 L water volume and a 207 bar service-pressure specification. Its listed dry weight is 7.2 kg.
What we like
We like this 5.7-litre option when an M25-threaded cylinder fits the planned setup.
What would make us think twice
Confirm the valve and approval for the exact cylinder supplied.
More about the L6X S40 P3403V Scuba Cylinder →Four checks before you place an order
- Establish the required capacity for the intended role through appropriate gas planning before comparing size or weight.
- Confirm cylinder identity, current inspection condition, service pressure, valve and compatible connection with qualified support.
- Check body dimensions and assembled fit with the intended mounting equipment.
- Have buoyancy and the complete configuration assessed; do not infer a ballast change from one catalogue figure.
Ask for a quote for the complete kit, including the accessories you need. That makes the price comparison much more useful.
Price, accessories and owning the equipment
A cylinder purchase is more than the metal body. Valve configuration, inspection status, compatible service and fill access, shipping and any required mounting hardware affect its usefulness and total cost. Check current local requirements with qualified suppliers rather than assuming a foreign listing is immediately usable where you dive.
Buying used? Start with the cylinder markings, inspection history and the local shop that will fill it. Brand preference comes after those checks. Ask a qualified cylinder inspector about anything uncertain before paying.
How we scored these models & further reading
These are our subjective buying scores out of 100. We weigh the usefulness of the features, the intended diving or carrying job, and the compromises involved in owning the gear. They are not laboratory measurements, safety grades or customer averages. The verdict applies to the two named models, not everything either brand makes.
90–100: one of our first choices for the stated job. 80–89: a strong option with trade-offs. 70–79: a more specific fit. A different fit, camera, valve or dive plan can change which one you should buy.
Catalina Cylinders S30
Product details and further reading →Luxfer L6X S40 P3403V Scuba Cylinder
Product details and further reading →Questions worth settling
Can the smaller cylinder serve as bailout?
Its nominal capacity alone cannot answer that. The required gas depends on a specific plan, depth, conditions, breathing demand and applicable training. This comparison supplies documented dimensions and capacities; it does not approve either cylinder for a bailout role.
Which is the better buy for this particular comparison?
Confirm the valve and approval for the exact cylinder supplied. We like the shorter 4.3-litre option when a smaller cylinder is the deliberate requirement.
Our pick is where we would start. Choose the other model if its fit or features better match your setup—especially where a camera, valve, boot or exposure suit needs an exact match.
