PAUT Nozzle Weld Inspection

Nozzles are a critical part of piping and pressure vessels, the quality of which can directly affect the integrity and performance of the pressure system. Nozzles welded into the vessel require special inspection given the possibility of different types of defects that can be associated with the weld. The complex ‘saddle geometry’ sees the probe move from axial to circumferential alignment on the shell as it rotates 90° around the nozzle. An inspection method with high accuracy and precision is required to determine this critical analysis. Inaccuracy in inspection can lead to weld failure, which can result in significant, costly damage.

To ensure quality and safety, nozzle weld inspection using the phased array ultrasonic testing (PAUT) method is often relied upon. The ability of this advanced non-destructive testing (NDT) method helps to identify minute discontinuities as instruments conform to complex geometries, ensuring the safe operation of the system.

The Need for Nozzle Weld Inspection

Inlet or outlet nozzles are installed to connect the pressure vessel or large piping with the rest of the application. In connecting the nozzle to the vessel, the shell of the pressure vessel is tampered with to create an opening. As the nozzle is fused to the pressure vessel through welding, the stress path diverts towards this attached nozzle. The nozzle weld should be strong enough to withstand this stress and maintain the integrity of the pressure system. However, several factors can cause a nozzle weld to fail, such as:    

• Cracks in the weld due to residual stress or lack of fusion 
• Errors in the design of the nozzle and calculation of nozzle load 
• Discontinuities such as inclusions and porosity in the weld  
• Stress corrosion 

To ensure safe operations, any flaws within the nozzle weld need to be identified and remedied. Phased array ultrasonic testing using versatile, high-performance instrumentation featuring 3-D visualization software tools, a nozzle scanner, and carefully selected 2-D matrix array probes is an ideal nozzle weld inspection approach for detecting minute flaws. With the adaptation of PAUT technology, industries can maintain the integrity of pressure vessels by ensuring that the weld is free of flaws and discontinuities.  

Phased Array Ultrasonic Solutions for Nozzle Weld Inspection

Phased array ultrasonic testing allows inspectors to identify thickness, corrosion, cracks, and other flaws associated with nozzle welds. Powerful PAUT technology utilizes a range of instruments. PAUT probes are equipped with multiple transducers with the ability to emit high-frequency ultrasonic beams. As these beams are transmitted to the nozzle weld, technicians can easily identify minute flaws within the weld that can be a potential threat to the pressure system. The use of multiple transducers facilitates greater coverage of the inspection area, speeding up the process and saving time.

Often the complaint with traditional ultrasonic testing has been its inability to perform inspection along the complex geometries, leaving the chance of undetected flaws around the weld area where inclination changes. However, with the availability of advanced ultrasonic technology capabilities and specific scanning solutions, PAUT inspection can be carried out for complete coverage inspection. The right probes and scanner can easily conform to the circumferential changes to thoroughly inspect the weld areas for critical flaws.

This flexibility and ease of use provide a faster and more accurate volumetric inspection. With the ability to detect potential weld flaws and irregularities, industries can concentrate on optimizing their processes to ensure safety.

Ensuring Quality with Effective Nozzle Weld Inspection

Zetec provides a wide range of phased array ultrasonic NDT solutions for the precise and accurate inspection of nozzle welds. Reliable PAUT instrumentation such as the TOPAZ Family of Instruments with industrially proven UltraVision software allows comprehensive inspection of nozzle weld for any flaws to maintain safe operation, meet quality standards, and avoid potential pressure vessel failure. 

Zetec is a trusted name in high-performance NDT solutions. Our advanced PAUT instrumentations offer flexibility, accuracy, and precision in nozzle weld inspection to ensure the integrity of welds in the pressure system. To learn more about our NDT solutions, contact us today.