CGA-510 (POL): vapor withdrawal
CGA-510, often called a POL fitting, is the standard outlet for drawing vapor off the top of an LP-gas cylinder. Valve makers such as RegO list it as the vapor service connection on their cylinder valves (RegO 8556 product page). It is the same style of fitting used on many grills and heaters.
CGA-555: liquid withdrawal
CGA-555 is the standard cylinder valve outlet for liquid withdrawal of butane and propane (Concoa CGA connection chart). Liquid-withdrawal cylinder valves typically include a dip tube that reaches to the bottom of the cylinder and an excess flow valve that limits flow if a line breaks (RegO 9107K8A spec sheet, PDF).
Why it matters for bulk butane
- You get liquid, not vapor. Processes that need liquid butane need a liquid-withdrawal valve. Pulling liquid from a vapor valve is not what it is designed for.
- The threads are different. CGA-555 and CGA-510 are not interchangeable, so the fittings on your equipment must match, or you need a properly rated adapter.
- Safety features are built in. The excess flow valve and dip tube in a liquid-withdrawal valve are part of why the CGA-555 is the standard for this job.
Puretane cylinders
Puretane's 120 lb n-butane cylinders and 70/30 cylinders come with CGA-555 liquid dispensing valves, with male or female threading. Tell us which you need when you request a quote, and ask about our cylinder exchange for refills.
Frequently asked questions
Can I connect a CGA-555 cylinder to CGA-510 equipment?
Not directly. The connections are different, so you need matching fittings or a properly rated adapter for your equipment.
Which valve do Puretane cylinders use?
CGA-555 liquid dispensing valves, available with male or female threading.