Bypass Valve Testing Safety Valves Without Shutdown
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for function testing safety valves in process engineering plants often require shutting down the plant to assess leakage and closing rates, which disrupts normal operations and cannot detect these parameters without direct mechanical access.
Innovation Solution
A method and system using a bypass valve to create a controlled fluid flow and pressure situation at the safety valve, allowing for continuous sensing of its position and performance without affecting plant operations, utilizing a positioner to set desired fluid flow and pressure differences, and incorporating sensors to detect discrepancies indicating potential malfunctions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the safety valve is closed for function testing, then the valve position can be verified, but normal plant operation is greatly detrimented requiring complete plant shutdown
Solution Approach 1:
The system segments the testing function from the main safety valve by introducing a bypass valve that can be tested independently. The bypass valve handles the testing flow while the safety valve remains in its normal operational position, allowing separate verification of safety valve function without shutting down the plant.
Solution Approach 2:
The bypass valve acts as an intermediary element that enables function testing of the safety valve without directly closing the safety valve. By routing flow through the bypass valve during testing, the system can verify safety valve positioning and leakage characteristics while maintaining plant operation through the bypass path.
2Measurement precision
If direct mechanical access is used to sense leakage and closing rate, then these parameters can be detected, but the testing process becomes complex and requires plant shutdown
Solution Approach 1:
The system replaces direct mechanical sensing of leakage and closing rate with flow-based measurement. By measuring flow rate and pressure differential across the safety valve during testing, the system can calculate leakage and closing rate parameters without complex mechanical sensors or direct contact with the valve mechanism.
Solution Approach 2:
The testing system uses pneumatic/hydraulic principles to measure valve performance. Flow meters and pressure sensors detect fluid dynamics parameters, which are then used to infer leakage rates and closing characteristics of the safety valve, avoiding direct mechanical measurement approaches.
3Quantity of substance
If the bypass valve is fully opened for testing, then flow can be redirected, but the predetermined flow conditions needed for accurate testing cannot be maintained
Solution Approach 1:
The bypass valve is designed with dynamic positioning capability, allowing it to be adjusted to a specific test position rather than being fully open or closed. This dynamic adjustment enables the system to maintain predetermined flow conditions through the bypass while still redirecting sufficient flow for testing purposes.
Solution Approach 2:
The system changes the operational parameters of the bypass valve from binary (fully open/closed) to a specific intermediate test position. By controlling the bypass valve to a predetermined position, the system maintains accurate flow conditions necessary for testing while ensuring adequate flow redirection through the bypass path.
Data Source
AI summary
In a method or system for function testing of a safety valve in engineering plant, it is tested whether the safety valve travels from a normal position to a predetermined final position in a certain operating situation of the plant. A bypass the valve bypasses the safety valve and assumes an idle position in a normal operation of the plant and a predetermined test position for function testing of the safety valve. The test position of the bypass valve is established such that a predetermined fluid flow through the bypass valve is permitted.