Tri-Clamp Fitting, AISI 304 Stainless Steel

01 · DN40 OR DN50: MEASURE THE FERRULE

Two numbers and the doubt is over

A ferrule of about 50.5 mm outside diameter is DN40, the equivalent of the inch-and-a-half Tri-Clamp, which is the usual calibre of the honey line. One of about 64 mm is DN50, the two-inch Tri-Clamp.

With that measurement taken, buying is straightforward. Without it the trade name misleads: the same joint is called DN40 or 1.5 inches depending on the catalogue, and it does not always match the inside diameter of the pipe.

02 · WHAT SEALS IS THE GASKET

The clamp only squeezes

The system joins two ferrules with the gasket between them — silicone or EPDM — and the clamp spreads the pressure evenly as the hinge closes on the wing screw. It opens and closes in seconds, even with gloves on, and it comes apart without tools for cleaning.

Hence the practical consequence: a joint that drips is almost never the clamp's fault, it is the gasket, which flattens and hardens with heat cycles. It is worth keeping spare gaskets and checking them before the season. The closure holds up well to the vibration of pumps and transfer lines, but it does not replace a threaded joint where pressure is high and continuous.

03 · BEFORE YOU BUY

Cheap, and it decides whether the line drips or not.