Phased Array Ultrasonic Valve Inspection
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Solution Overview
Problem
Current non-intrusive inspection techniques for valves, particularly in nuclear power plants, fail to reliably detect wear or potential failures in swing-type and lift-type check valves, such as worn hinge pins or leaking lift-type check valves, which can lead to catastrophic failures.
Innovation Solution
The use of phased array sequence scanning with water wedges to non-invasively inspect swing-type and lift-type check valves, providing visualization of their operation by transmitting and receiving ultrasonic signals through piezo-electric crystals mounted on the valves, allowing for the detection of air pockets, wear, and proper operation, including the position and integrity of the clapper nut and globe valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional non-intrusive inspection techniques (acoustic, magnetic) are used to monitor valve operation, then the valve can be monitored without disassembly, but these techniques cannot detect wear on the hinge pin of disc-type check valves
Solution Approach 1:
The patent replaces traditional acoustic and magnetic inspection techniques with phased array ultrasonic inspection. The ultrasonic waves interact with the mechanical structure of the valve, particularly the hinge pin and clapper assembly, allowing detection of wear and structural changes that other methods cannot detect. The ultrasonic signals provide direct mechanical interaction with the components to detect wear conditions.
Solution Approach 2:
The patent changes the inspection parameter from acoustic/magnetic field measurements to ultrasonic wave propagation characteristics. By measuring ultrasonic signal reflections, transmission times, and amplitude changes as the valve operates, the system can detect subtle changes in hinge pin wear and clapper position that indicate impending failure.
2Loss of information
If flow checking is used to determine valve operation, then the valve operation can be monitored, but no detailed information about internal valve condition or component integrity is obtained
Solution Approach 1:
The patent uses ultrasonic waves as an intermediary to probe the internal structure and operation of the valve. The ultrasonic signals act as a mediator that can penetrate the valve body and interact with internal components like the hinge pin and clapper, providing information about their condition and position without direct contact or disassembly of the valve.
Solution Approach 2:
The patent adds a new dimension of inspection by using ultrasonic wave propagation through the valve structure. Instead of only monitoring flow parameters, the system measures ultrasonic signal characteristics (time of flight, amplitude, frequency) that provide spatial and structural information about valve components, creating a multi-dimensional assessment of valve health.
3Loss of information
If the valve is disassembled to obtain detailed inspection information, then comprehensive internal condition data can be obtained, but the valve must be taken out of service and downtime occurs
Solution Approach 1:
The patent enables the valve to essentially inspect itself during normal operation. The ultrasonic inspection system monitors the valve's own components (hinge pin, clapper, seat) while the valve is in service, allowing the valve to provide information about its own condition without requiring external intervention or disassembly. This self-monitoring capability eliminates the need for scheduled shutdowns for inspection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables accurate, non-invasive monitoring of valve operation, detecting issues like wear and leaks, preventing potential failures by providing a visual representation of valve performance, allowing for timely maintenance and ensuring safe operation in nuclear power plants.
Implementation Method 1
transmitting and receiving ultrasonic signals through piezo-electric crystals mounted on the valves
Implementation Method 2
phased array sequence scanning with water wedges to non-invasively inspect swing-type and lift-type check valves, providing visualization of their operation by transmitting and receiving ultrasonic signals
Data Source
AI summary
A computer with a proper program generates a phased array sequence of signals. In a pulser with delays, the signals are fed through a multiplexor into multiple water wedges that are attached to a globe valve being tested. For a sequential operation of the globe valves from the open to the closed position, ultrasonic signals are transmitted through the fluid contained in the valve and reflected back through piezo-electric crystals to the multiplexor. By summation and merger of the signals, an image can be developed of the operation of the globe valve to determine if the globe valve is operating properly. By comparing the signals received with a known standard for that globe valve, proper operation, or lack thereof, of the globe valve under test can be determined. Separation of the valve stem from the globe can also be measured.