Recent content by otised

I don't really have anything more to say on this. Unless you are trying to replace a Mark I (or Mark II) control with a microprocessor control, there isn't a whole lot to be gained by trying to make a 1 for 1 comparison between them. GE (and some competitors) have been supplying these...

WTF is correct that there are many differences going from Mark I control systems to Mark VI. Mark I was the first electronic gas turbine control system for GE. The sequencing and master protective circuits were all relay logic. The speed, exhaust temperature and fuel control circuits were...

While I have been retired from the business since late 2009, I have 2 recommendations: 1. My "bible" for sizing control valves was "Control Valve Handbook" by Fisher Controls. Find a copy. 2. Avoid setting foot in any facility where the control valves were sized by dummies.

Thermocouple failure modes are: Open Circuit, which the Mark V should indicate as a low temperature; or Short Circuit, which offers multiple options: 1, short between the thermocuople leads, which the Mark v would read as the temperature at the location of the short. 2. short between either or...

A comment or two: I believe the 5002C is an upgrade to the 5002A which uses the "Mary" axial compressor on the gas turbine HP shaft, which would mean fixed IGV's. That means a hang-up in IGV control is NOT a source of the problem. (If, in fact, the "C" is an upgrade to the "B" then that uses...

The accuracy depends on the accuracy of the dp transmitter AND the primary flow element. If you want +/- 1% accuracy, you must start with a calibrated flow element. That gets you a certified calibration sheet for the flow element. It also costs you more.

I have comments on IGV control and SRV control. The comments apply to a properly tuned system with control devices calibrated to their specifications and with the hydraulic control oil pressure within specifications. Regarding IGVs: When the IGVs are operated in temperature control mode...

CSA, Overall, your cost estimates look reasonable. I will confirm that no Mark IVs were used for steam turbine control. The Mark IV was the first microprocessor based GE gas turbine control. At the time it was put into service, GE Steam Turbine was making their own control panels (not using...

Shahabas, You don't say anything about what type of gas turbine is driving the compressor. Is it a GE design or some other design? is it single shaft or 2 shaft? Is it heavy duty or aircraft derivative? What is the rpm it is being rotated at? Do you know for certain that it is reverse...

The instrument will operate and run properly. However, it will no longer be an intrinsically safe installation, it will not meet Ex requirements because in the event of a power supply failure there will be the capability of producing a spark with sufficient energy to ignite an explosive gas.

I don't know what your budget is, but back before I retired (over 9 years ago) our normal practice for boiler drum level measurement was to use differential pressure transmitters (with pressure compensation) for control and indication, with a code required independent measurement for indication...

GE supplies a fuel system that is designed for the heating value defined by the purchaser. They basically match the fuel nozzles to the specified gas. You would likely need to contact GE to see what changes (if any) are required to use your gas. It is possible control settings can be made to...

Abdullah, At 50 MW the IGV's are likely near the minimum angle and at 120 MW they are near or at maximum angle (you didn't identify which model gas turbine you have). Therefore the airflow through the gas turbine is significantly less at 50 MW. Also, at low IGV angle you may have inlet bleed...

From the information you have provided, I would suspect the problem to be in a solenoid that operates when L14HS (or L14HSX) picks up. You may be able to troubleshoot this when shut down. Compressor Bleed Valves would be one of the first things I would look at, but there are a lot of things that...

>As long as you have a properly calibrated temperature >sensor in the incoming steam, the amount of super-heat tells >you everything. ryanb clearly stated that the steam is saturated, so there is no superheat. I don't have any knowledge of a method of measuring the quality of saturated...