"mm" wrote in message
...

At least the first time I would take one to get recharged, I would
find it very interesting to see the place where they do it. If I'm
lucky, I'll get to see the shop. Of course I might not get past the
counter. He he might trade me one that is already recharged for my
empty one, but I'd still find the place interesting.

Here is how they recharge dry chemical fire extinguishers.

Step one. Discharge the old unit into a container.

Step two. Inspect the inside to be sure it is empty and dry inside.

Step three. Inspect O-rings and replace as needed.

Step four. Inspect hydro-test inspection stamp and re-hydro-test if due.

Step five. Insert funnel and refill dry chemical filtering out any lumps,
weigh to assure full charge.

Step six. Install new internal inspection sticker on dip tube.

Step seven. Reassemble and charge with dry nitrogen.

Step eight. Install a charge tag and seal on outside.

The two big items are the hydro test and the cost of the chemical if the
extinguisher has been used. The latter is usually no big deal as the chem.
is baking soda with an anti caking agent and the units that fail the hydro
test add to the supply of powder. The hydro test is no big deal either. it
is done the dame way they do welding tanks, just with a lower test pressure.
The big issue is the additional time it takes to test and dry the tank.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.