Part No. DP0V-0040 (2) DP0V pressure check valves, brass Replacement parts for hand pumps, calibration manifolds, nitrogen sources and volume contollers Features • Made in the USA DP0V-0040 Ralston Instruments Inc. | ralstoninst.com | Toll Free 800-347-6575 | Phone 440-564-1430 | Fax 440-564-1480