Gum Rubber Boots and Sleeves, Every Size We Cut

How to size a boot

The number we need is the inside diameter of the finished sleeve, which is the outside diameter of whatever it slips over. That is where most sizing errors start. Pipe is named by its nominal size and measured by something else: 8 inch pipe is 8.625 inches across, 10 inch pipe is 10.75, and 12 inch pipe is 12.75. Order a boot named for the nominal size and it will not go on.

Wall thickness is chosen for what is running through it, not for the diameter. Fine material like cement, fly ash, flour and dust runs fine at 1/4 inch. Aggregate, rock and anything with sharp edges wants 3/8 inch, and a high-wear spot like a truck discharge boot should be 1/2 inch. Going heavier than the duty calls for makes the sleeve stiff and harder to clamp, so heavier is not automatically better.

Length is the gap the boot spans plus 3 to 4 inches of overlap on each end so the clamp band has rubber to grip. The builder takes lengths up to 48 inches. Longer than that is still a normal order, it just needs a conversation, so type your number in and we will quote it.

Still not sure? Read the FAQ, look at a similar part in our example applications, or find your equipment on the industries pages.

Hot vulcanized, also called heat vulcanized

You will hear both. Some plants and some catalogs say hot vulcanized, others say heat vulcanized, and a few say cured seam. They all describe the same thing: the overlap is joined with uncured rubber and set under heat and pressure until it becomes one continuous piece.

What matters is the alternative. A cold-bonded seam is two finished faces held together with adhesive, and it is the first thing to give out when a band clamp squeezes it and the sleeve flexes a few thousand times. Every boot and sleeve we cut is heat vulcanized, whichever word you use for it.