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The Responsive Respiratory oxygen cylinder wrench is a small plastic key built for CGA-870 post-valve oxygen cylinders, the compact pin-indexed type most often seen in medical and portable-oxygen use. It is worth considering if you own that style of cylinder and want a lightweight spare key. Skip it if your oxygen cylinder is a full-size welding or cutting tank with a handwheel, because that is a different valve.
Oxygen Cylinder Wrench at a Glance
| Item | Per the listing |
|---|---|
| Product | Responsive Respiratory oxygen cylinder wrench |
| Intended valve | CGA-870 post valve |
| Material | ABS plastic |
| Size | About 5 x 5 x 0.3 in |
| Weight | About 0.3 oz |
| Check before buying | Your cylinder’s valve style and the wrench opening shape |
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What This Wrench Is and Who It Suits
A post-valve oxygen cylinder has a small stem on top that is turned a fraction of a turn to open or close the flow. Many people use a flat key for this, and a plastic one is light enough to keep on a lanyard or in a kit bag. This model is described as a round-head ABS wrench, so it works as a simple hand key rather than a heavy-duty shop tool.
It suits owners of small oxygen cylinders who want a spare key, and it can suit shops that keep small oxygen cylinders for tasks like light brazing or lab work. It is not a general-purpose gas wrench and it will not substitute for the correct tool on other gas cylinders.
How to Check It Fits Your Cylinder
- Identify the valve. Pin-indexed yoke cylinders use CGA 870. Large welding oxygen cylinders normally use a handwheel and a CGA 540 outlet, which this wrench is not described for.
- Match the stem. Compare the stem shape on your cylinder to the wrench opening. If the listing images do not clearly show a match, ask the seller before ordering.
- Check the cylinder label. It should say oxygen and show the service pressure. Never use this tool on a cylinder you cannot identify.
- Check your regulator. A wrench does not fix a mismatched regulator. Use a regulator made for oxygen and for your cylinder connection.
Pros and Limitations
Pros
- Very light and compact, easy to keep with the cylinder.
- Plastic construction means no steel-on-brass marring of the valve stem.
- Inexpensive category of tool, so a spare is easy to justify.
Limitations
- Fits a narrow valve type, so it is the wrong tool for most welding oxygen tanks.
- Plastic can crack or round off if forced, so it is not for stuck valves.
- The listing gives no torque rating, so treat it as a light-duty key.
Using an Oxygen Cylinder Wrench Safely
Oxygen does not burn by itself, but it makes everything else burn much harder, and oil or grease in contact with high-pressure oxygen can ignite. A few habits keep this safe.
- Keep hands, gloves and tools free of oil and grease before you touch the valve or regulator.
- Back the regulator adjusting screw out, then open the cylinder valve slowly and stand to the side of the gauge face.
- Do not force a stuck valve. Close it, tag the cylinder and return it to the supplier.
- Secure the cylinder upright with a chain or stand, and cap it when it is not in use.
- Never use oil on oxygen fittings, and leak test connections with soapy water.
- Store the wrench dry, away from solvents and heat, and replace it if it cracks.
Alternatives and Related Guides
- If you cut or heat with oxy-fuel, read the oxygen acetylene cutting torch kit review for what a complete setup includes.
- For a welding-grade oxygen regulator, see the Uniweld RO100 oxygen regulator review.
- The CDL LX45 oxygen brass regulator review covers another oxygen regulator option.
- For connecting hose and fittings, look at the oxy-acetylene brass quick connect review.
Frequently Asked Questions
Will this wrench open a welding oxygen cylinder?
Probably not, and you should not assume it will. The listing describes it for CGA-870 post-valve cylinders, the small pin-indexed medical type. Full-size welding oxygen cylinders usually have a handwheel valve and a CGA 540 outlet, so check your cylinder before buying.
Is a plastic cylinder wrench safe around oxygen?
A plastic wrench avoids the sparks and oil contamination risk of a greasy steel tool, which is a reasonable point in its favor. Keep it clean and dry, never lubricate it, and replace it if it cracks or the opening rounds off.
Does a wrench replace a regulator or flow meter?
No. The wrench only opens and closes the cylinder valve. You still need a correctly rated oxygen regulator that matches the cylinder connection, and you should open the valve slowly with the regulator adjusting screw backed out.
How do I know which valve my cylinder has?
Look at the valve and any label. A small cylinder with two pin holes for a yoke clamp is the CGA 870 pin-index style. A large cylinder with a handwheel and a threaded outlet is the usual welding style. When unsure, ask your gas supplier.
Verdict
This is a simple, light key for CGA-870 post-valve oxygen cylinders and nothing more. Confirm your valve type first, then check the current listing for the exact opening shape.
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