Iron • PVC • Concrete • Clay • Rail Pads • TSG's • Extruded • Flange • Viploc VIP-Heinke manufactures a wide range of seals for predominantly pressure applications for the PVC pipe market. Seals for Plastic Pipe VIP-Heinke PVC Pipe Seals are generally manufactured to the customers' own design and specific requirements VIP-Heinke also offers its own proprietary, patented Viploc seals which contains a polypropylene stiffening ring to provide seals with extra rigidity. For low to non-pressure applications, VIP-Heinke manufactures products which are generally of lip seal configuration. The company has also developed and patented its own seal designs which work on a compression seal basis and is uniform in terms of its design around the central axis of the seal, thus allowing easy insertion into the pipe groove without the need of having the seal in a specific orientation as is sometimes required with lip seal designs. VIP-Heinke has developed a proprietary system for welding a rubber seal into a plastic housing providing better control during assembly of the seal into the fitting and also to improve speed of assembly.