Component Related Documentation

In its simplest form, a check valve is a one-way directional control valve. It allows free flow in one direction while blocking flow in the other direction. In the free flow direction, the poppet or ball cracks open at a pressure equal to the bias spring rating, allowing air to pass through the valve. This is usually at a very low or nominal pressure, but can be specified to a specific spring force to give back pressure in some applications.

Safety Related Notes

Before working on this machine, perform lockout-tagout procedures per the rules of your plant. Determine the sources of energy on this machine – electrical, pneumatic and hydraulic – and release or vent sources of stored energy – electrical capacitors, air receivers, and hydraulic accumulators. Shut off sources of power – electrical, pneumatic and hydraulic. Safely block mechanical sources of energy such as loaded springs and loaded machine members, or safely position the machine members so they are unloaded and springs are not under tension. Beware of hot hydraulic fluid and hot surfaces which can cause burns. Never “crack a hydraulic or pneumatic fitting” to check for the presence of stored energy. Hydraulic fluid injection injuries, as well as injection injuries from many other fluids, are extremely serious and must be treated immediately by medical personnel familiar with this type of injury. Loss of body parts or death may result from improperly treated fluid injection injuries! Never use your hands to feel for a hydraulic leak! Never use compressed air to blow dust off yourself or someone else – there is risk of an air injection injury. Review the schematics and think before proceeding to work on the machine to ensure you have made the machine safe to work on.