numbers and sizes are found on the packaging label.
components have multiple heat numbers.
You must match the heat number to the correct size.
Reducing fittings will list the heat number for the
largest diameter first then for the smaller diameter.
fittings have multiple heat numbers.
These are listed by process tube first then by
containment tube. If the part is a reducing fitting
they are listed from larger to smaller diameter of
process then larger to smaller for containment.