Slip-on flange
tap orifice flanges are less expensive
than weld neck, but they are more
expensive to use if the meter tube
is to be fabricated to A.G.A. Report
No. 3 requirements. This report states,
"When slip-on orifice flanges
are used, the end of the - should
be welded flush with the face of the
flange and then machined smooth on
the flange face. Such machining shall
not change the tap hole locations."
'Any distortion of the pipe resulting
from welding of the slip-on flange
shall be removed by machining or grinding."
The cost of making two welds on a
slip-on flange as compared to one
weld on a weld neck will, as a rule,
cost more than the difference in the
cost of the flanges. Therefore, the
machining is all extra cost.
