Servo Valves

There are a wide range of gas turbine fuel systems being utilized throughout the world, many of which are dual fuel engines, meaning that they alternate between natural gas and diesel fuel for turbine operation. While significant advances have been made in the electronic control of these fuel media, the hardware remained virtually unchanged for the back-up liquid fuel system for decades.

In order to improve dual fuel engine performance and reliability, JASC developed a variety of products:

• Check valves which use water to cool their internal components preventing diesel fuel from solidifying while the turbine is operating on natural gas.
• Purge air check valves which are capable of sealing to ANSI class 6 standards (bubble tight) while requiring only 1/2 psi of pressure to open.
• Water injection check valves that provide an ANSI class 6 seal and are not prone to excessive wear due to high frequency oscillation or chatter.
• Three-way purge valves capable of alternating between purge air and liquid fuel. Additionally, a water-cooled version of the design prevents solidification of diesel fuel in it as well.

JASC Installations provides services which fully integrate these products into an existing dual fuel engine system to minimize cost while addressing the fundamental issues impacting reliability.

In this day and time, it is rare that the most effective solution to a problem is also the least expensive. Relative to dual fuel systems, JASC has accomplished this feat for installation of back-up liquid fuel system upgrades, operational reliability and total cost of ownership. Transfer success can be improved from the industry norm of 30% to rates approaching 100%. The formula for success is as straight forward as it is simple. Specifically, provide bolt-in hardware that closely matches the turbine owners’ currently installed configuration to minimize piping changes; design hardware which is capable of making the system in which it is installed operate at levels that approach 100% reliability and availability. Couple these characteristics with savings ranging from $100,000 to $1,000,000 per turbine on installation costs alone and you have an option which warrants consideration in any dual fuel engine system upgrade discussion.

For an “F” class gas turbine which utilizes liquid fuel check valves, an upgrade would be about 1/3 the cost of other options. Components supplied for the dual fuel engine upgrade would include water-cooled liquid fuel check valves, water injection flow proportioning valves and a Smart Fluid Monitor. The type of purge air valve used would determine whether a JASC designed valve would be required. Savings on installation would be at least $100,000 per turbine. Savings on other models of turbines would be greater.

For an “F” class gas turbine which utilizes three-way purge valves, a dual fuel system upgrade would be about 1/5 the cost of other options. Required equipment would include water-cooled three-way purge valves, water injection flow proportioning valves and a Smart Fluid Monitor. A gas turbines owner’s savings for an installation would be approximately $1,000,000 per turbine. The significant difference in cost is tied directly to the technology, which is available for this particular configuration.