2015 News Archives
JASC Sets Industry Standard for Gas Turbine Liquid Fuel System Reliability
JASC’s Schuyler McElrath was recently interviewed for Energy Power News Las Vegas 2015. Below is the article from that interview.
Schuyler V. McElrath joined JASC in 2004 after 25 years of employment at the GE Energy gas turbine manufacturing facility in Greenville South Carolina. During his tenure at GE, he worked in quality as turbine test operator, test technician, technical specialist, and operations leader for accessory base manufacturing and test. During the last decade of McElrath’s employment with GE, he moved to global sourcing as a sourcing quality engineer where, as the program manager, responsibilities included outsourcing the manufacturing/test of frame 6B and frame 7EA accessory skids. Resolution of fleet issues for both component and system failures were also within the scope of this assignment. The knowledge gained from these challenging roles coupled with JASC’s design acumen has allowed the development of products that set the industry standard for gas turbine liquid fuel system reliability.
Q: Please start by telling us a bit about the company, a brief history of JASC and an overview of your business today.
A: Jansen’s Aircraft Systems Controls (JASC) was founded in 1990 by Harvey Jansen, who had over 50 years of engineering experience in fluid control systems. JASC provides practical engineering solutions for aerospace, space and gas turbine industries as well as providing installation services for power generation facilities.
Q: Please tell us about the company’s products.
A: For the power generation industry, JASC specializes in the design and manufacture of products that enhance the reliability of back-up liquid fuel systems. One of our most significant innovations is the actively cooled valve design. It comes in the form of either a check valve or three-way purge valve. These components have become the foundation for resolving a multitude of issues that have negatively affected back-up liquid fuel system operational capability and reliability for decades. Benefits of actively cooled valves include, but are not limited to, natural gas to liquid fuel transfer success rates approaching 100 percent, no maintenance or service for the fuel system hardware until major turbine outage intervals are reached, and the avoidance of multiple start attempts on liquid fuel. Improved reliability for fuel system components such as flow dividers, fuel pumps, and fuel nozzles have also been achieved. Enhancing gas turbine fuel flexibility with actively cooled valve designs is a simple, inexpensive, yet elegant approach for addressing back-up liquid fuel system reliability.
Q: What would you say makes your business unique?
A: All of JASC’s products were created as a direct result of resolving our valued customers’ field issues. Our in-depth analysis of both hardware and systems has yielded many design innovations that were patentable. Consequently, our unique turbine fuel system expertise allows us to support our customers in a manner that exceeds that of the typical supplier.
Enhancing Gas Turbine Fuel Flexibility
JASC actively cooled fuel valve designs upgrade standard liquid fuel check valves and 3-way purge valves. More importantly, these modifications significantly enhance gas turbine transfer capability from the primary natural gas system to the back-up liquid fuel system.
JASC’s actively cooled fuel control valves mitigate fuel oil degradation in high temperature turbine compartment environments. The absence of coke formation on valve internal components and liquid fuel supply lines due to high temperature has an immediate impact on turbine fuel system reliability. Specifically, our coke-free valve’s ability to maintain an ANSI Class VI seal prevents compressor discharge pressure and purge air from back-flowing through the valves and evacuating the liquid fuel system. Active cooling is also applied to the liquid fuel supply lines, thus allowing extended intervals of turbine operation on natural gas without liquid fuel viscosity increases which impact valve reverse flow sealing functionality when internal surfaces are coated with fuel that is the consistency of tar.
Common control diagnostic faults such as high exhaust temperature spreads, excessive fuel flow trips and high exhaust temperature trips will also be significantly reduced, if not eliminated altogether. These fault and trip conditions are symptomatic of fuel lines which have been evacuated by leaking fuel control valves. While increasing pre-fill timers is one of the typical recommendations for addressing the issue of fuel system evacuation, large pockets of air always remain in the fuel system and manifest as faults, trips and catastrophic failures of fuel pumps, flow dividers and fuel filters.
Benefits of actively cooled valves include, but are not limited to, natural gas to liquid fuel transfer success rates approaching 100%, no maintenance or service for the fuel system hardware until major turbine outage intervals are reached and the avoidance of multiple start attempts on liquid fuel. Improved reliability for fuel system components such as flow dividers, fuel pumps and fuel nozzles will also be achieved. Enhancing gas turbine fuel flexibility with actively cooled valves is a simple, inexpensive, yet elegant approach for addressing back-up liquid fuel system reliability.
Would You Like to Know More?
Visit us at Power-Gen, Las Vegas! We’ll be at booth 9715.
About JASC Controls
For over 20 years, JASC Controls has been supporting both gas turbine OEMs and turbine owners with fuel system design, development, hardware failure analysis, product improvement and fuel system troubleshooting. During this time, a wide array of products have been invented to address issues which impact operational capability for the back-up liquid fuel system on dual fuel gas turbines. All of JASC’s products were created as a direct result of resolving our valued customer’s field issues. Our in-depth analysis of both hardware and systems has resulted in many design innovations which are patented. Consequently, our unique expertise allows us to support our customers in a manner which exceeds that of the typical supplier. Our goal is to achieve availability and reliability approaching 100% from major turbine outage to major turbine outage. Contact us at sales@JASC-Controls.com or call 602-438-4400 for additional information.
Solving the Gas Turbine Back-up Liquid Fuel System Reliability Issue
Addressing system inadequacies is a fundamental part of improving the overall reliability of the liquid fuel system and its related components. High system and environmental temperatures naturally create a situation ideal for coke formation. Operationally compromised control system components are responsible for the inability to start on liquid fuel or transfer from gas to liquid fuel.
Check valve failures, flow divider failures, fuel system evacuation, exhaust temperature spreads, and other related turbine trips have been resolved with an array of patented designs developed by JASC including:
- Water-cooled valves for prevention of coking formation.
- Water-cooled 3-way purge valves with a water-cooled flange for use on DLN turbines using primary and/or secondary liquid fuel.
- Smart Fluid Monitor providing leak detection and automatic shut-off of cooling water to valves and flame detectors should faults occur.
- Multiple-use crush gasket technology, which replaces elastomeric O-rings.
JASC Positional Tee with Water-Cooled Liquid Fuel Check Valve
These system-specific products have three common design goals. First, provide reliable valve function and system operation until a scheduled turbine service interval is reached.
Second, the valves must maintain better than ANSI ClassVI sealing capability from installation until removal for refurbishment. Elimination of combustion gas back-flow results in back-up fuel system availability and reliability typically exceeding 98%.
Third, incorporation of JASC’s new metal to metal seal fitting design serves as replacements for O-rings and other elastomeric materials.
Positional tee with distributor
The “Tee” designs can be used on standard or DLN fuel nozzles, they are SAE J1926 compatible, provide adjustable orientation for easy connection interface to existing piping, and are rated for continuous service at high temperature and pressure.
JASC’s solutions are configured to be interchangeable with the turbine’s existing hardware. This minimizes project cost and time associated with performing a fuel system upgrade.
Transferring from gas to liquid fuel, starting on liquid fuel, and executing these sequences without tripping the turbine allows systems to be exercised regularly with no negative impact. Case studies of power plants that have performed JASC fuel system upgrades reveal that after five years of operation, maintenance typically consists of normal refurbishment of the JASC check valves.
For more information about the products in the above diagram, see the links below:
Two decades of innovative product development and implementation demonstrates that gas turbine owners can realize significantly reduced operation and maintenance costs when a JASC fuel system upgrade is performed.
Learn more about JASC’s unique products and services by contacting your local Power Generation representative: https://jasc-controls.com/about/partner-alliances