Sample Extraction Probes
Impurities like silica and chlorides attack HP, IP, and LP turbines, resulting in blade erosion and stress corrosion cracking (SCC). A well-designed SWAS system monitors these threats 24/7, but proper analysis requires proper extraction.
Forbes Marshall Isokinetic Probes ensure you are not just sampling the stagnant water at the pipe’s boundary wall. By capturing droplets and steam at the exact kinetic velocity of the main flow, these probes provide a flawless, real-time picture of carryover effects and corrosion products in high-pressure super critical power plants. Their core value lies in their ability to match process flow velocities exactly, ensuring compliance with ASTM D1066 and ASME PTC 19.11-2008 under extreme thermal and hydraulic stress.
Applications of Isokinetic Sample Extraction Probes:
Super critical power plants, boiler heat exchangers, low-pressure condensate lines, and any process requiring 24/7 assessment of water/steam chemistry.
- True Representative Extraction: Avoids the “boundary effect” to accurately capture corrosion products and measure carryover effects in saturated steam
- Extreme Durability: Features a rugged design that is highly resistant to massive thermal and hydraulic stresses in high-temperature pipelines
- Global Compliance: Designed explicitly to meet strict ASTM D1066, EPRI, ASME PTC 19.11-2008, and European VGB-S-006 standards
- Corrosion Prevention: Allows for immediate, precise assessment of steam chemistry (pH, chlorides, fluorides), enabling rapid corrective action to prevent turbine erosion
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Frequently Asked Questions
Isokinetic probes extract samples at the exact velocity of the main flow, which avoids the boundary effect and provides a truly representative sample of impurities like silica and chlorides.
Non-isokinetic extraction leads to inaccurate water chemistry assessments, which can allow corrosive impurities to attack the turbines, causing blade erosion and stress corrosion cracking (SCC).
Yes, they are ruggedly designed to be highly resistant to thermal and hydraulic stress, making them suitable for the high pressures and temperatures found in super critical power plants.
Yes, they are fully designed as per American standards including ASTM D1066 for steam sampling and ASTM D3370 for water sampling.
Yes, Forbes Marshall offers both welded mounting and flanged mounting options for the fixed probe designs.
