On Thu, 17 Feb 2005 08:58:13 -0600, Duane Bozarth
wrote:

Doug Miller wrote:
...
Not unless you're talking about some pretty small pipes.

Nominal 3/4" pipe is a bit under 7/8" actual diameter, and hence approximately
2.75" in circumference. The joint is about 3/4" deep, so the total area of the
joint is around two square inches. Thus the total force exerted on the area of
the joint, at 60 psi, would be around 120 pounds.
...

Depends on which force(s) you're talking about.
The force that is exerted in trying to force the
joint apart endwise (pulling the pipe out of
the fitting) is proportional to the cross-sectional
area of the pipe. Since the pipe is probably
not actually all the way home against the stops,
you'd use the OD of the pipe to calculate this.

The force that's trying to squeeze the solder out
from between the pipe and the fitting is proportional
to the area of the seam between the pipe and fitting,
wich you would calculate by taking the difference
between the OD of the pipe, and the ID of the
fitting.

The "bursting force" applied to the part of the pipe
that's inside the fitting, would be found by multiplying
the ID of the pipe by Pii and again by the length inserted,
but that last force is pretty much irrelevent, since it's
resisted by the pipe-metal itself.

Is all cases, the pressure exerted by the system when
everything is still will be dwarfed by the pressures exerted
when someone shuts off a fixture somewhere.
(This is one of the few things about which a normal
gate valve is better than a ball valve. Gate valves
close more slowly.)

--Goedjn