Lee manufacturers two types of check valves, standard insert and restrictor, for installation in either metal or plastic, to combine hydraulic systems into a single, accurate flow. Insert valves are available in both forward and reverse flows, in either axial or side exit styles and are designed for hydraulic and brake fluids, fuel and petroleum products. Lee restrictor check valves are 5.5mm, cartridge style.

Specialty manufactures and distributes a variety of check and shuttle valves composed of electroless nickel plate brass and stainless steel, in a range of sizes including  1/16, 2/32, 1/8 barb, 10-32F and 10-32-M. Suitable applications include arefrigeration, oxygen, cryogenics, gas, water and air.

Cole-Palmer distributes a range of mini check valves in sizes between 0.25" and 0.1875", for maximum temperatures up to 250F. Available materials include nylon/fluorosilicone, Viton and Kalrez.

Smart Products features series 500 miniature check valves in barb, female luer and male luer configurations. Smart miniature check valves are compact, one-piece and tamper-resistant, and are designed for both liquid and air systems. Barb valves are available in 1.58mm and 3.18mm.

U.S. Plastics offer 695 series, general purpose mini check valve, designed for both horizontal and vertical installation, in low-resistance, high flow systems. Available materials are standard nylon, as well as polypropylene for high resistance against chemicals with positive seal at pressure points, up to 125psi. All 695 series mini check valves are 1/2 inch diameter, with stainless steel ball and spring operation.

Circle Valve Technologies, Inc. is a distributor of valve products from a variety of manufacturers. Available products include the series 2200 miniature check valves in sizes ranging from 1/8" to 1" and made of brass or stainless steel, with medium flow design, resilient o-ring and single piece design.