Nuclear and Non-Nuclear Fabrication and Equipment Repair

Valve Services

NNI is able to test, adjust and repair all types of valves and actuators, both in the field and in our valve shop. This capability begins with in-house training programs that range from basic valve repair to advanced training on safety valves, pressure seal valves, AOVs and MOVs for both technicians and supervisors. NNI’s state-of-the art valve shop is equipped to test and repair all types and sizes of valves and actuators. The facility has gas, liquid and steam testing capability including a 1,500 psi steam boiler and a 10,000 psi Caulder test stand. When onsite repairs are called for, NNI’s mobile machine shop and portable equipment provide the right tools for the project. NNI’s project management, supervision and planning resources enable them to meet all customer requirements, from staff augmentation projects to turn-key valve programs.

Valve Testing and Repair Services

Inspection/Testing

  • Visual condition examination on opening to detect unnatural wear or corrosion
  • PT, MT, wet fluorescent MT, UT, and RT techniques to detect cracks and discontinuities in pipe and plate
  • Eddy current testing for identifying surface cracks
  • Dimensional verification to check as-found fit of components against stated tolerances
  • Material analysis
  • Testing
  • Leak testing using water, air/gas, or steam to industry-recognized or customer-specified standards
  • Set-point testing using water, air/gas, or steam. In-service set-point testing with auxiliary lift assist equipment
  • Specialized testing (flow, function, strain/deflection, etc.)
  • Diagnostic testing of AOVs, MOVs, and check valves by personnel manufacturer-qualified on the equipment and software to be used (field only)
  • Megger readings and other electrical tests on motor
  • No-load testing
  • Vacuum testing

Adjustment & Set-Up

  • Calibration of positioner on AOV
  • Bench setting of air actuator
  • Limit switch setting
  • Torque switch setting
  • Adjustment of SRV set-point
  • Change of SRV set-point

Repair & Refurbishment

  • Valve replacements, both flanged and welded
  • Valve repack/live-load pack using all vendor packing applications
  • Reseating
  • Seat replacement
  • Reverse engineering and parts fabrication
  • Replacement of seals and diaphragms
  • General machining
  • Weld repair, weld build-up, and weld prep reconfiguration
  • Modification during repair (e.g. upgrade of material, changing operation of check)
  • Re-threading
  • Hot taps
  • Replacement of actuators
  • Rebuilding of actuators
  • Routine preventive maintenance on actuators

Consulting Services

  • Valve maintenance program assessments
  • Valve maintenance program development
  • Valve application engineering
  • Valve repair training programs

Boiler Water Circulating Pumps

NNI has been in the Boiler Water Circulating Pump (BWCP) repair, refurbishment, and spare parts business for over 50 years. NNI’s expertise is in the “Canned” and “Wet Wound” style pumps providing complete repair services for all major BWCP types and manufacturers. NNI has a vast database of OEM drawings for all models of BWCPs and maintains an extensive inventory of spare parts.

NNI has repaired and refurbished over 1,200 pumps to include Westinghouse, General Electric, Hayward Tyler, Ingersoll Rand, Torishima, and KSB model BWCPs. Our services range from supplying spare parts, conducting routine maintenance, complete overhaul, and major repairs. NNI can construct and manufacture new BWCPs from the ground up.