All Ark-Plas® Check Valve barbs are molded without a parting line. This means that every sealing surface on each barb is seamless all the way around, eliminating flash, or mold mismatch. Coupled with our high-quality manufacturing processes, a barb without a parting line helps to ensure a leak-proof seal with each use. By nature of our free-floating design, Ark-Plas® Check Valves are "zero-gravity" fittings, and can be used in any position with immediate response to even the slightest change in pressure or flow. All Check Valves can be purchased in six different material / diaphragm combinations. Luer Style Check Valves offer the convenient on/off quick-disconnect design of the luer taper, accompanied with the assurance of a quality, leak proof seal. Our Luer Taper Check Valves are designed to ISO 594-1 and ISO 594-2 Standards for a 6% luer taper to assure compatibility with other luers manufactured to these high standards. Luer Check Valves are available in six configurations, featuring male and female Luers, with both locking swivel and slip connections. Currently, all Luer Style Check Valves come standard in clear polycarbonate, with a silicone diaphragm. Other materials are available for larger quantity orders. Each style of Standard Check Valve is stocked in one of four different materials: Kynar®, Polycarbonate, Nylon, and Polypropylene. These materials cover a wide range of chemical resistance, and physical properties. Kynar®, a registered trademark of Arkema Inc., features an excellent resistance to halogens, hot acids, alcohols, aromatics, oxidants, mild bases, aliphatics, fungus, abrasion, chloride, and ultraviolet rays. Polycarbonate is a transparent material, with high impact strength. Polycarbonate Check Valves are great for applications that require regular, visual inspection. Our most popular material, Nylon, functions exceptionally in most applications, and is known for its high strength-to-weight ratio, resistance to corrosion, and good mechanical characteristics. Polypropylene, our most economical material, offers an excellent chemical and moisture resistance. Check Valve diaphragm standard choices include Neoprene, Silicone, and Viton. Diaphragms should be matched closely to the body material by likeness in physical and chemical properties. This helps ensure that the best possible performance is achieved from Ark-Plas® Check Valves.