ALSO KNOWN AS “THRUST PLATES”, “HARNESS LUGS” OR “GUSSET PLATES”
TRUMBULL FLANGE LUGS are used to prevent separation of plain-end
piping components. They are installed on the back sides of ANSI Class
125 B16.1 and Class 150 B16.5 flanges to allow tie rods to span across
an unrestrained piping component. One example is with a flexible
coupling as illustrated below.
Trumbull Flange Lugs are also used with rubber expansion joints to
limit their expansion. Uncontrolled expansion can lead to failure of
rubber expansion joints.
When using threaded ductile iron flanges, check for clearance of the
Flange Lug inner radius with the flange hub O.D. Two flange lugs are
used in conjunction with a tie rod, two flat washers and four hex nuts
to comprise one set. At least two sets are required per joint. Longer
flange bolts are required at the flange lug to accept the plate
thickness.
NOTE: The total number of flange lugs required should be determined
by the project Engineer, or the expansion joint manufacturer.
Material is ASTM A36 carbon steel plate and 304 stainless
steel. Carbon steel lugs are supplied with a Tnemec 37-77 red primer
coating; other coatings and finishes are available upon request. Flange
Lugs for Class 250 / 300 are available upon request.
