What is LR 90 elbow?
Long Radius 90° Elbows make a 90 degree change of direction in the run of the pipe. The radius of the bend in this elbow is “long radius”, or in other words, greater than that of the nominal size.A 90° elbow long tangent is a long radius (LR) with the centerline curvature equal to 1-1/2 times the nominal pipe size (NPS) and a straight extension at both ends (long tangent) for 2 inch and larger sizes. Tangent elbows provide a straight length at the end to accept a Slip-on Flange.
Cerification of LR 90 elbow
|ANSI/ASME B 16.9/MSS SP43
|Q235,20#,35#,45#,20G,ASTM A234 WPB/WPC
|Low Tem Carbon Steel
|Q345B,16Mn,ASTM A420 WPL6
|ASTM A860 WPHY 42/46/46/60/65
|ASTM A234 WP11/WP12/WP5/WP9/WP91/WP92,15CrMoG
|ASTM A403 WP304/304L/304H,316,316L,310S,317,347,904L
Advantagaes of Butt welding elbows
Butt weld elbow is a steel elbow formed by hot pressing or forging. Its connection form is to directly weld the elbow and steel pipe. Butt welded elbows are mainly used for elbow with higher pressure and temperature than other connection types (socket welded elbow or threaded pipe elbow)