Repair & Refurbishment

Industry best practices have shown the benefits of performing disassembly, inspection, and refurbishment on pressure relief valves regularly. A regular repair program maximizes in-service valve performance and as-found testing compliance with all codes and standards.

Qualifications and Expertise

At NWS, we have the broadest industry capability for repair of valves from nuclear facilities. Our comprehensive program includes the following services.

Visual Inspection

Our staff is qualified and trained to perform ASME Boiler & Pressure Vessel Code Section XI VT-1, VT-2 and VT-3 visual examinations.

Types of examinations include:

VT-1 of Pressure Retaining Bolting (bolts, studs, nuts)
VT-2 leakage examinations of pressure retaining valve components
VT-3 of Valve Bodies – internal surfaces and components
Liquid Penetrant Testing (PT)​ and Radiographic Testing (RT)

PT and RT examinations are performed on a variety of valve components, including machined and welded items.

Spring Rate Testing

Spring inspection and rate testing is a key aspect of valve reliability and set pressure repeatability. NWS maintains equipment, procedures, and qualified individuals to ensure spring integrity.


We offer in-house turning, grinding, milling, polishing, and cutting capabilities for complete valve repair and restoration. NWS generates custom machine repair plans to ensure component surface finish and dimensional tolerances are in compliance with OEM specifications.


The NWS ASME Section IX Welding Program is an integral part of our repair services. The Welding Program is audited by NUPIC, and accepted by the National Board of Boiler & Pressure Vessel Inspectors. NWS Welding Procedure Specifications (WPS’s) have been reviewed and approved for use by numerous Nuclear Utilities. NWS has the ability to develop new welding procedures to meet customer needs. All Procedure Qualification Records (PQR), Welding Procedure Specifications (WPS), and Welder Performance Qualifications (WPQ) are performed in accordance with ASME B&PV Code Section IX – latest edition, the NWS Quality Assurance Manual, and the NWS “VR” / “NR” Manuals.

No other company offers in-house repairs, inspections, NDE, machining, welding, QA/QC, Radiation Protection, testing, and certification services. Our technicians all have thousands of hours experiencing the full range of the refurbishment process.

How NWS's Repair Program Can Help You

NWS can provide repair services to support emergent customer needs and meet required schedules. We provide lower cost and shorter delivery compared to new components while maintaining the high-level quality required for these critical components. There have been multiple instances that customers have required new valves from the OEM be sent to NWS prior to installation due to the high-quality service we provide and their confidence in our abilities.

NWS Technicians have repaired thousands of valves and performed in-depth root cause analyses. We have developed a comprehensive understanding of failure modes and methods to optimize valve performance. These practices are implemented in our repair procedures to ensure valve reliability and extend service lifetime.

Let’s Talk About It

Ready to scope and schedule a repair project? Let’s discuss the specifics.