That looks like a leaking old original regulator. The common
replacements sold for at least the last 10 years have round diaphragms,
not square ones like the originals. The replacements are longer because
of this and the propane pipes don't fit without shortening them or
changing their bends. For this reason some people try to avoid replacing
the original regulator, though all of them need replacement by now. You
need a new one.

Mark

Steve Williams wrote:
> What is this small hole in the face of my propane regulator?
>
> I've stopped using the propane system until I can understand why
> there's propane leaking out of that hole!
>
> http://mira.sbw.org/photos/20120528/P1000510/
>
> More photos:
>
> http://mira.sbw.org/photos/20120528/
>
> Van Cafe in Santa Cruz installed this new propane tank, valve, and
> regulator in January, 2011. I've used it only a few times since.
>
> Last time I used it, when I opened the valve, I noticed a hiss. I
> located the leak with my thumb. My nose and my electronic propane
> sniffer confirmed it was propane, so I shut the valve and decided to
> wait until I can find out what the deal is!
>
> Is this an overflow vent of some kind? If so, is there a better way
> to vent the tank/pressure down to the correct level? Sounds kinda
> dangerous.
>