• Knowledge - Since 1972, GPK has been manufacturing molded and fabricated PVC sewer fittings for the waterworks industry. We understand the critical nature of product applications and engineer our products to exceed the demands of the job. • Field-Tested, Superior Products - Our heavy-duty, molded fittings are made from a proprietary resin and feature thicker walls, deeper bells and a better gasket design. They not only meet but also exceed ASTM standards. They’re made to stay where they are placed so crews can set them – and forget them. • Above & Beyond Customer Service - We know that time is money and understand the value of good relationships. Our responsive, knowledgeable team delivers personalized service and is empowered to do whatever it takes to meet our customers’ – and their customers’ – needs. • A Company You Can Trust - When you work with GPK, you work with people who understand your business and your application and are committed to your success. We’re a company you can trust to say what we mean and do what we say to help you meet your customers’ needs and exceed their expectations. • Comprehensive Product Line - At GPK, we understand the wide range of products that waterworks projects dictate. That’s why we offer an expansive product line, with more sizes, configurations and types of fittings to meet any application. • Made in America’s Heartland - GPK PVC fittings and flexible couplings are made in the heartland of the U.S. Our products are the go-to for government contracts and American-made product specifications.