"Neon John" wrote in message
Geez, I wonder how all those millions of oil, wood and coal-fired furnace
water
heating loops manage to operate without a special grant of privilege from
Congress?
Maybe some day some academic will do a study and figure out why Usenet
seems to
attract such a concentration of dickhead-isms.

For a simple application like this, a simple water heater P-T relief valve
is more
than adequate. As far as the bureaucracies go, there is no involvement
until a
certain large firing rate. In Ga it is 1.5 million BTU per unit. TN's is
a little
lower - can't recall exactly - but still above 1 million BTU.

John

In Mass, it is pressure. Anything with a 15 psi relief valve is OK, no
matter the size. At 15 psi and over you need a different license depending
on size. Up to 299 hp you need a special or a 2nd class fireman, at 300 hp
you need an engineer full time. etc. There is an exception for very small
boilers but I forget the size.

In any case, it is not very difficult to make a loop that would be safe and
not require input from any government agency.