Application:  Trim Modification for Reactor Water Clean-Up (RWCU) Flow Control Valve

Project Description:  Trim Upgrade of Original Hammel Dahl 4″ 600# Globe Control Valve

Valve Description:  4″ 600# Globe Control Valve with Piston Actuator

Typical Valve Assembly Drawings:  V500L-5, V500L-6

Typical Valve Tag Numbers:  G31-F033, G31-1239, G33-F033

Typical Valve Model Number:  V500NFC92ZZZ9

Typical Actuator Model Number:  A32AJD6FBZ

Drawing of Typical RWCU Valve Trim Modification Kit:  HP1201622

Objectives of Retrofit

  • Address damage to plug and cage due to stroking of valve under high DP flow conditions
  • Maintain original flow characteristics and operational parameters original design
  • Improve internal shutoff capability of valve
  • Reduce susceptibility of valve to seat damage as a result of high DP flow conditions
  • Re-use of existing actuator without any adjustments to established set-up parameters

Features and Benefits of Retrofit Package

  • Replacement of original O-ring Plug Seal with custom-engineered spring-energized UHMWPE Plug Seal
    • Offers improved sealing capability
    • More resistant to damage under high flow conditions
    • Material provides excellent radiation resistance
  • Re-design of Plug profile to incorporate relief area(s) in outer diameter of Plug
    • Creates better pressure balance under dynamic fluid conditions
    • Reduces side-loading on Plug during stroke
    • Reduces frictional drag
    • Reduces risk of galling of Plug and Cage interacting surfaces during stroke
  • Use of case-hardened (i.e. Nitrided) 410 Martensitic Stainless Steel for materials of Plug, Cage, and Seat
    • Increases galling resistance of mated sliding surfaces of Plug and Cage
    • Reduces risk of localized damage to seating surfaces from steam cutting, etc.