Flexible Couplings

Flexible couplings join dissimilar pipe materials and absorb misalignment where a rigid fitting cannot. MEKCO Supply stocks rubber couplings, shielded and MJ couplings, and zip couplings from Lyncar, BOSHART and our 5M line.

Choosing a coupling

The critical measurement is the outside diameter of both pipes, not their nominal size. Cast iron, plastic and clay pipe of the same nominal size have different ODs, which is exactly why transition couplings exist — a CI x PL coupling is stepped to suit both.

Unshielded rubber couplings are for above-ground, non-pressure DWV use and where the joint stays accessible. Shielded couplings, with a stainless steel band over the sleeve, resist shear and are what most jurisdictions require for buried applications — check with your inspector before backfilling, because an unshielded coupling underground is a common failed inspection.

Torque the clamps to the manufacturer's specification. Over-tightening distorts the sleeve and is as likely to leak as under-tightening.

Repairs and transitions

Flexible couplings are the fastest way to tie new plastic into existing cast iron during a repair or renovation. We stock the common transition sizes at our Richmond Hill counter for same-day pickup.