At 12:33 AM 5/27/2013, Fuzzy :philippe wrote:
>It has a little chain attached to it to prevent it from being lost if
>it gets unscrewed.

The fill valve is the standard ACME-type** fill valve for ASME
***propane tanks used on RVs and fixed installations where a truck
comes to fill rather than swap bottles.  Any RV place, any propane
service facility should have caps for them.

**ACME actually refers to the design of the screw thread, a modified
square thread with a flat top and 27 degree (included angle) flanks.

***American Society of Mechanical Engineers.  ASME-type tanks are
much more heavily constructed than BBQ/DOT-type tanks.

Yours,
David