Thomas & Betts XJG74-EMT EMT Expansion Coupling, 2 1/2 In, 4 In Travel

The XJG74-EMT is sized for 2-1/2 inch EMT and allows 4 inches of total travel. That travel is what absorbs thermal expansion and contraction in a long straight run, so on a typical installation you set the coupling near mid-travel to leave room for movement in both directions.

No. The XJG74-EMT is built for EMT, which has a thinner wall and no threads. Rigid metal conduit and IMC are threaded and need a threaded expansion fitting instead. Using the EMT version on rigid will not give you a proper mechanical or grounding connection.

Ductile iron. That makes the XJG74-EMT suited to metal EMT runs where the fitting also has to take mechanical abuse. If you are running PVC conduit, you want a PVC expansion fitting instead, such as the Cantex 5133591 5 Series or the Kraloy EJ25 expansion joint.

The XJG74-EMT is an EMT expansion coupling built in ductile iron, so it terminates to steel EMT, not to rigid nonmetallic conduit. For a PVC run, use a PVC expansion fitting instead: the Cantex 5133591 is a 5 Series PVC expansion coupling, and the Kraloy EJ25 is a PVC expansion joint. Both are solvent-welded into PVC rather than fastened to EMT, so the decision follows the raceway type already in the wall or slab.

A standard coupling locks two lengths of EMT together rigidly. Across a building expansion joint, a long exterior run, or a parking structure, the conduit grows and shrinks with temperature and that movement has to go somewhere, or it bends the raceway and loads the boxes. An expansion coupling like the XJG74-EMT lets the conduit slide, 4 inches of travel in this case, while keeping the raceway continuous.

Treat it as a sliding joint, not a guaranteed ground path. Standard practice on EMT expansion fittings is to install an external bonding jumper across the coupling so equipment grounding continuity is maintained as the conduit moves through its 4 inches of travel. Plan on the jumper and clamps as separate items.

No. The Cantex 5133591 is a 5 Series PVC expansion coupling, while the XJG74-EMT is a ductile iron expansion coupling for 2 1/2 inch EMT with 4 inches of travel. They serve the same purpose - absorbing thermal movement in a raceway - but they connect to different conduit systems, so one does not drop into the other's opening.

The Thomas & Betts XJG74-EMT is a ductile iron expansion coupling sized for 2 1/2 inch EMT and rated for 4 inches of travel, which suits a metallic raceway crossing a structural joint where the conduit itself is steel. The Kraloy EJ25 is a PVC expansion joint, intended for nonmetallic conduit. Pick by what the conduit is made of; a metal run needs the metallic fitting to keep the raceway continuous.

XJG74-EMT. The XJG series number identifies the trade size and travel, and the EMT suffix is the key detail, it distinguishes the EMT version from the threaded rigid versions in the same series. Order by the full designation including the suffix.

Both are nonmetallic expansion fittings. The Cantex 5133591 is a 5 Series PVC expansion coupling and the Kraloy EJ25 is a PVC expansion joint, so either addresses thermal movement in a PVC run; the series designation is the main way to match what is already specified on the drawing. Neither one accepts EMT - for a 2 1/2 inch EMT run with 4 inches of travel, the Thomas & Betts XJG74-EMT is the metallic counterpart.