Buying Aftermarket Blades for a Siemens SGT-600

Write four fields before anyone talks money. Material on the turbine rows is typically a nickel superalloy in the Inconel family. Process is investment cast, then machine, then heat treat. Coating, where the row is coated, is usually an over-aluminide or an MCrAlY system. Tests include fluorescent penetrant inspection, radiography, and an airflow check on cooled gas-generator rows. After those four, add the original-equipment number — OEM in every store — the stage, whether the part sits in the gas generator or the free power turbine, the quantity, and the outage date. That is a request a foundry can answer.

The gas generator, often written GG, makes the hot gas. Its turbine rows may be cooled and they live at a different temperature from the free power turbine. Copying a power-turbine specification onto a gas-generator row is how the wrong cooling map arrives in the crate. Siemens-style B, C and D intervals change which GG rows come out. Freeze the bill of materials when the outage level is known. Euroturbine will send the list back if GG and PT are mixed on one line.

An SGT-600 station on a gas line opens a C-interval. The list is gas-generator stage-1 turbine blades, OEM number from the last shop report, quantity for a full row, hours and starts on that package, new-make, plus airflow on the cooled row. Euroturbine prices that as GG. A power-turbine shroud from the same package stays on a different line.

The free power turbine, often written PT, takes the gas and turns the load shaft. On this frame it is two uncooled stages. The shrouds lock one blade to the next. That lock gives the row stiffness and damping. It is part of the vibration case the original designer signed. An aftermarket blade that almost matches the airfoil but loses the lock is a different part. Euroturbine will measure the shroud interface on a coordinate measuring machine — CMM in every shop — not only the fir-tree root. If a sample arrives with a worn lock, we rebuild the nominal interface, not the worn one.

The same SGT-600 station is missing a power-turbine row. That stops the station, not a slide in a brochure. The request is PT stage 2, OEM number, quantity for a matched set, photographs of the shroud lock from both neighbours, new-make. Euroturbine will not ship loose airfoils that only look like the sample from one side.

Mixing one aftermarket blade into an OEM power-turbine row needs a written note on mass and frequency that engineering has signed. A silent mix is how a row that looked fine on the bench picks up a vibration limit in service. Euroturbine prefers a matched set, or a documented mix, over a substitution that only appears on the packing list.

If the station already has fifty-nine OEM blades and one scrap, send the scrap serial, the OEM number, hours, and say you want a documented mix. We write mass and frequency before the blade is allowed into that row. If you cannot accept that paper, the honest job is a matched set, not one hopeful spare.

A request we can price without sending the list back looks like this. Nameplate: SGT-600, package serial if you have it. Section: gas generator or free power turbine — not «بلید SGT-600». Stage and rotating or stationary. OEM number from the last shop report. Quantity: full row or named serials. Hours and starts. Job: new-make, repair, or a documented mix. If the row has already run, last coating record and last NDT — non-destructive testing. Photographs: root, both sides of the airfoil, and on a PT row the shroud lock. Outage date and whether the interval is B, C or D. Do not reuse an SGT-600 number on an SGT-400 request. Those are separate frames and the bins in the store already get mixed often enough.

SGT-600 parts · Emergency parts · Buying checklist