Check valves 

PacSeal

Check valves provide unidirectional flow, sealing against reverse flow, and are commonly used on the outlet side of a pump.   Check valves are manufactured with zinc plated carbon body and hardened stainless steel in-line poppet to provide a metal-to-metal seal for long life in hydraulic oil and lubricated water.

Dr. Breit

Dr. Breit Throttle Valves are now available at Hydraulic Systems Pte Ltd. Throttle valves are best used in flow metering while adjusting the required flow of the needle valve. You can use this even on both flow directions to control the speed of the actuator. However, for parallel flow path the reverse flow will be blocked if you are equipped with a check...

SC

PRESSURES UP TO 15,000-PSI COMPATIBLE WITH MOST FLUIDS STAINLESS STEEL CONSTRUCTION CAPABLE OF RESISTING HIGH SHOCK LOADS CRACKING PRESSURE WITHIN 1-PSI TO 3-PSI SC Hydraulic Engineering inline check valves are designed for high shock loads using a ball check for positive sealing. The all stainless steel construction will handle most liquids or gas....