Originally manufactured in The Netherlands, the HDL ball check valve product has been offered since 1912 and has been a mainstay in the wastewater market as well as a variety of other markets including mining, automotive, industrial, and chemical markets. Available in sizes 1 ½” – 24”, valves up to 12” are stocked by GPM and its distributors for immediate delivery. Available in ductile iron construction, with NPT sizes (through 2”) in 316 SS. For more demanding applications in larger sizes, a flame spray coating is offered for all wetted surface to reduce or eliminate corrosion or abrasion concerns. HDL ball check valves have long been the sewage and waste water non-return check valve of choice, but can be applied to a myriad of other systems as a non-return check valve. With only one moving part, maintenance for your non-return check valve will not get any simpler.