Doug Miller wrote:
....
Speaking of which, if the water pressure is 60PSI, does that mean the
maximum pressure on the joint is 22 pounds?

Nope, 60 psi.

I have to be more careful with my wording. Of course the pressure is 60psi;
I meant "force". There is less than a half inch cross section (3/4" pipe),
so that comes to about 22 pounds.

How do you figure that? The area of a 3/4" diameter circle is 0.44 square
inches. 60 * 0.44 = 26.4.

Or does it not work that way?

Sure, but the area of the joint is, well, it's the area of the joint. It's not
the same as the cross-sectional area of the pipe.

Correct...it's the "wetted perimeter"...there's a total of (pi*id) in^2
of surface area on the inner wall of the pipe/unit length.

However, as you note there is no portion of the solder joint that is
directly exposed to the water except that which fills the annulus
between the OD of the pipe and the ID of the fitting...that's a much
smaller area.