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You don't say where the level calculation is being done. If in a DCS or PLC, then you could automatically switch between the max vacuum and atmospheric offsets based on whether or not the vacuum pumps are running, assuming the vacuum pumps status is also monitored in the same DCS or PLC.

Seismic probes measure velocity. They are typically mounted on a bearing cap, and measure the rate (velocity) the machine is moving. Units are inches (or cm) per second. Proximity probes measure displacement. While they also are mounted on the bearing cap, they are measuring the size of the...

You may have a problem with the P2 pressure setpoint calculation. From your description it looks like the SRV is controlling to a pressure setpoint that is too high. The setpoint is a function of HP speed. You should verify that the SRV control loop settings are all correct per the GE Control...

Just to back you up on the fired hours, October 2009 is only 9 months ago. There are only 8760 hours in a 365 day year! 29000 hours is 3.3 years.

Steam is not a perfect gas; it is not even an ideal gas! That's why we use steam tables and Moliere charts. Even so, Charles law would still permit the pressure to remain constant (actually it will decrease passing through the superheater) as long as the volume increased. The perfect gas...

Expressing flow of a gas in terms of normal cubic meters per time unit is effectively a mass flow rather than a volumetric flow. It only has meaning if the substance is a gas at normal conditions. If 1 cubic meter of the gas weighed 0.5 kg at normal conditions, then 1000 Nm3/minute is the same...

What, exactly, is a normal cubic meter of saturated steam? Superheated steam does not exist at normal conditions!! (Normal conditions are 0 deg C temperature and 1 atm pressure.)

You don't say whether the Mark VI is the GT control or whether it is a BOP (DCS) control panel. If GT, then all calculations will be done in English units. If BOP, they may be in SI units. Regardless, you need to use a consistent set of units for the mass flow block. There is an input to it...

Be careful using this - note the volume unit is "scf" = standard cubic foot - which is at 60degF and14.696 psia. You wanted "acf" = actual cubic foot - which is at actual temperature and pressure.

You need the orifice manufacturer's calibration data. You can use whatever data point is provided, so long as the fluid (gas composition) has not changed. All you need is one point where you have the pressure, temperature, flow, density and differential pressure. It is best if that point is your...

The easiest way to calculate the K1 or K2 constant is as follows: 1. Get a copy of the orifice data sheet provided by the orifice supplier. Look at the design point in the data sheet. There will you will have defined flow (in either mass units or volumetric units or both if you are lucky), at...

Density is calculated from the gas properties and varies with temperature and pressure. You still haven't said what type of flowmeter you have. If it is a differential pressure instrument across an orifice, flow nozzle or venturi, then you should also have pressure and temperature...

Do you need Standard cubic feet/minute or Actual cubic feet/minute? If Standard, just figure out how many pounds are in a Standard cubic foot of the gas (standard conditions are 60 degF at 14.7 psia) and convert: SCFM = PPH / (Pounds/SCF) / (60 min/hr) If Actual, then it depends on what...

It is still not clear where the bypass connection for the IP steam is. The arrangement I am familiar with on a multishaft combined cycle plant is: HP bypass dumps to cold reheat; IP superheated steam also dumps to cold reheat; IP bypass is from hot reheat to condenser. Hot reheat connects...

You don't provide enough information. The problem is whatever caused the IP drum pressure to drop. The drop in pressure is what caused the swell and high-high level trip. Does the IP superheated steam go directly to the ST or does it go to cold reheat (assuming there is a reheater)? Do you...

JW - have you contacted GE about fast start options? Fast Start and Fast Load Start are options available on most of GE's gas turbine product line. You need to understand that fast starts do take more life out of the unit than normal starts.

If you are going to monitor the wiring all the way out to the field contacts, the resistor must be placed at the field contacts. If you put it in the marshaling cabinet you are only monitoring the wiring between the control I/O and the marshaling cabinet.

You really haven't given us much to go on. There is nothing in the standard GE 2-shaft turbine control that can "lock" the LP rotor, so I would tend to say you have a mechanical problem, most likely in the load equipment, whatever that is. Where there any alarms while the unit was last...

You might be overlooking the point that temperature has a bigger impact on pipe and pressure vessel strength than pressure. The instrument tubing is uninsulated and outside and therefore is at a much lower temperature than the insulated piping and steam drums, etc. Also, the tubing being much...

As a backup, I would put a time delay (maybe 10 seconds - check with the turbine supplier) on feedback that the steam turbine stop valves have closed and there has been a trip command and use that to trip the turbine in the event that the reverse power relay failed to operate. You don't want the...