Here is a Miniboot holding a 20"hg vacuum. Try that with any other low cost seal!
Miniboots used from the outside in
Miniboot used from the inside out
The "Flash Free" Pipe Seal
The Miniboot Pipe Seal is the only LOW COST, 4 inch, clamp-able seal that passes vacuum testing!
Made of low density polyethylene. Is has a closed face and an easily removed pull-out disc that opens the seal for use. It is a bi-directional seal. Works from inside or out. Clamp-able either way. Allows for extremely angled pipe placement. Accepts 4.250 inch sdr-35 thru 4.75 inch c-900 pipe.Use the URP-432 to reduce to 3 or 2 inches.
The Miniboot is not only a great pipe seal but also a great concrete seal, providing a "flash free" finish inside and outside of the casting. Straight/taper jackets and round forms are no problem. The mandrel does not contact the core so if a seal is mis-placed oris not needed, a thick concrete web forms in it's place. No more buried seals or flash jamming the back of the seal. It’s a pipe seal for under a dollar that passes astm vacuum tests.
A word about compatibility:
I am always asked if the Miniboot will fit existing mandrels (the tool that holds the seal in the concrete form during the "pour"). Miniboots are unlike other competing pipe seals, which makes them incompatible with the mandrels used by the others. The competing mandrels press tight to the core of the mold. If they are not "tight enough", concrete flash forms around the seal, burying the seal in concrete, jamming it up, and, in the process of finding it to use it, destroying it. This leaves the customer, engineer, and regulator very unhappy!
The Miniboot mandrel stays away from the core about 1/2 to 3/4 inch (but it can go closer). The maximum is 3/4 inch but if you want to put the mandrel tight to the core, that works too. When the concrete form closes up, the Miniboot will stretch and mushroom out, making that "flash free" seal. When the form is stripped, the Miniboot snaps back to it's original size, forming a crisp, clean finish. If the mandrel is set at 1/2 to 3/4 inches, the seal can be left off if not needed on a particular pour. A thick knock-out is left in it's place. The same stands true if the Miniboot is misplaced upon closing the form. A thick knock-out is better than a gaping hole! Rissy even has a product to deal with that! Ask about the TSB-400.
Note that since the seal lip of the Miniboot rolls into the casting, some clearance must be allowed in the corners. Two Miniboots cannot be tight to a common corner. One must be an inch or so away.
Rissy Plastics will supply 2 inch wall mandrels free with a reasonable Miniboot purchase. For thicker walls, contact us for mandrel extenders, at a reasonable cost.
The cost of Miniboot pipe seals is slightly more than the competition. This is because Rissy does not have the volume to sell them for "peanuts". If you try the Miniboot, I think you will agree that you get what you pay for. And try to pass the ASTM vacuum test with the competitors seals. They don't offer one that can for under a dollar, let alone five!
Nuff sed!
Miniboot™ Pipe Seal MB-4
US Patent 5941535