The calculated strength from a Slip On flange under internal pressure is of the order of two-thirds that of Welding Neck flanges, and their life under fatigue is about one-third that of the latter.
The connection with the pipe is done with 2 fillet welds, as well at the outside as also at the inside of the flange.
The X measure on the image, are approximately:
Wall thickness of pipe + 3 mm.
This space is necessary, to do not damage the flange face, during the welding process.
A disadvantage of the flange is, that principle always firstly a pipe must be welded and then just a fitting. A combination of flange and elbow or flange and tee is not possible, because named fittings have not a straight end, that complete slid in the Slip On flange.
Our slip-on flanges are available with raised, flat, or RTJ faces, and are also available in orifice configurations.
These flanges are available in all of our stainless steel and chrome-moly grades, from ½” to 36” and beyond, class 150 to 2500. We also stock large diameter LDS Slip-On flanges in A105N, and can supply all sizes of LDS Slip-Ons and AWWA C207 Slip-Ons – with or without a hub – with longer lead times. We can also source many of your other specification requirements.