NOV Mission has four types of ANSON Check Valves: Top Entry (cast or forged steel) and In-line (swing or dart). Check Valves are used in pipelines to allow flow in one direction while protecting the equipment and processes. Hammer Unions are the standard end connections. However, Top Entry Valves can be supplied with Flanged or Hubbed connections. All ANSON Check Valves are standardized with a unique identifying number and full material traceability.