SURVEY PREPARATION
 The valve and trap leak testing process may seem overly complicated and time consuming. But you can rest assured that we have mastered the process. We work with our clients throughout the testing process to help eliminate test anxiety. We provide all of the tools and expertise necessary to make your experience easy and stress-free.
Preparation is the key to success. We create an individual database and test procedure specific to each client site. It’s a tedious process. But with very little plant assistance, we manage to put it all together. It predetermines each item's importance to testing and potential impact on plant efficiency.
The first steps toward a successful valve and trap leak survey are:
- Plant Diagram Review
- Test Plan Selection
- Loss Potential Analysis
- Database Creation
- Custom Troubleshooting Plans (Nuclear)
When combined, these five steps serve as the back bone of our service.
Plant Diagram Review
Leak Detection Services, Inc. (LDS) tests normally closed valves and traps used to control the flow of steam, water, liquids, and gasses common to power plants and other industrial plant environments.
The review process involves identifying each item for testing and any associated items, such as blocks and bypasses. The goal of the review is to identify all valves and traps that, if leaking, will negatively impact efficiency and/or operations.
The goal of the detailed review is to determine the:
 Function of each valve to be tested.
Value and the direction of the differential pressure.
Nature of the fluid across the valve.
Likely temperature of the fluid and the piping.
Physical location of the valve.
Normal and current positions [open/closed/regulating] of the valves.
Physical characteristics of the valve such as: Type, diameter, material, and actuation.
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Test Plan Selection
Next, Leak Detection Services, Inc. (LDS) determines an appropriate test procedure for each test group. The patented ValveAlyzer®; System maintains an on-board library of test plans. It also gives up the ability to create custom test plans as needed.
Several factors are considered when selecting the correct test plan. An appropriate test plan ensures that:
The initial valve lineup matches the normal positions of the valves involved.
The sequence of the steps is chosen to assure that all
valves are never opened simultaneously.
The isolation valves are tested (if possible) as well as the more important valves.
All valves are always returned to their normal position after the test is completed.
Leak Detection Services, Inc. provides four standard test methods to ensure test completion. There are multiple variations of the appropriate test plans for each test method.
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Loss Potential Analysis
Leak Detection Services, Inc. provides potential loss analysis as part of its cycle isolation loss valve and trap testing service. Our clients each use this proprietary tool to assist in the implementation of a successful valve maintenance program.
Loss impact depends on what is leaking, where the leak goes, and how bad it is. A large leak is not always more economically important than a medium leak.
LDS receives and reviews heat balance diagrams at current megawatt output level and we make initial loss potential calculations.
To estimate the effect of losses from each individual valve, we make calculations based on the plant parameters, calculating for each item the percentage of the total cycle isolation leakage that is potentially due to that item.
The result is a useful ordering of valves in terms of their potential effect on cycle isolation and output. We use this information to guide our in-plant testing.
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Database Creation
The final step is database creation. It combines the findings of the plant diagram review, test plan selection, and loss potential analysis into one central location. The database is used throughout the testing process to ensure all tests are completed and done so safely.
The database maintains client results. Initially, they are used to confirm the effectiveness of repairs.
Historical results are used to aid in the identification of chronic leakers and new leakers. Eventually, historical data can be used as a baseline for the purpose of quick testing. If a quick test shows a possible new leak, then a complete testing of all blocks and bypasses is required. This eliminates the possibility of cross talk.
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Custom Troubleshooting Plans
Most nuclear plants require formal troubleshooting plans. We prepare them for your review after we have selected specific test plans for each cycle isolation valve to be tested. Some plants convert them to permanent procedures for future surveys.
Each custom troubleshooting plan is designed for each test plan used in order to meet site specific requirements. Typically each troubleshooting plan describes the:
Errors and malfunctions to be addressed
Expected plant response (Annunciators, indications,automatic actuations, etc.)
Potential problems, results, and termination criteria
Initial plant/system conditions
Step by Step instructions
Restoration to normal operation – Plant and any related Systems
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