Description:Cat® Check Valve is designed to provide a uni-directional fluid flow and prevent back flow. This type of valve used will depend on the size of the pipe, the overall pressure that the system operates, the flowing media, process conditions, and other factors. Cat® Valves are designed to provide a fluid flow in hydraulic fluid lines in Cat heavy duty equipment's. With longer maintenance intervals, this extends your work cycles which saves you time and reduces lost revenue due to downtime. Choosing genuine Cat® Parts is a wise investment for your hard-working equipment.Port Thread Size - TPI - A in : 7/8 - 14 UNF - 2BPort Thread Size - TPI - B in : 9/16 - 18 UNF - 2BPort Thread Size - TPI - C in : 9/16 - 18 UNF - 2BApplication:Consult your owner's manual or contact your local Cat Dealer for more information.