Why specific order for jacking of Gas turbine is followed before casing bolts opening and casing lifting?

And

During HGPI, should all the jacks placed and jacked keeping in view we only required to lift combustion wrapper and turbine casings?

 

How is this topic even remotely related to controls?

 

It is not related to controls. I agree.

But this is a platform where Gas Turbine experts can help me out. It basically involves some design characteristics.

 

Why we put mechanical jacks in turbine , compressor & CDC underneath at HGPI

 

Arjun075,

It's to ensure the turbine control system doesn't experience any grounds (earth shorts).

Or maybe it's to prevent any sagging of the casings (axial compressor, combustion wrapper and turbine shell casings) at the bolted joints so that upper casings can be lifted off without binding. When the upper and lower casings are all bolted together it makes for a very firm arrangement; when the casings are split there is nothing to keep the lower halves from sagging under their own weight and the weight of the rotor--which makes removal and installation of the upper halves extremely difficult, if not impossible.

In any case, it's common practice and an excellent procedure to follow to ensure smooth disassembly and reassembly during the inspections (HGPIs (Hot Gas Path Inspections) and Majors). Deviate from it at your own risk. Some have tried; most have failed, some with very serious consequences to schedules and equipment.

The turbine control system doesn't like grounds (earth shorts), either. And most mechanical crews working on turbines have little to zero respect for conduits (which they consider to be ladder rungs and hand rails) and wiring (which they consider to be nuisances). And, if they have to stay on the job longer because of damaged conduit and/or wiring, they get unexpected pay. And, they don't have to shift to another site so quickly. Electrical stuff isn't their "responsibility" and few are held accountable for damaging conduit, wiring or field devices which weren't removed to save time (money)--which is almost ALWAYS a huge mistake.

But, this is a controls-related forum. I shouldn't be discussing the poor practices of maintenance personnel and their supervisors.

We shouldn't be having the discussion of this thread at all, but, people will be people and we try to be somewhat helpful. We usually succeed, but sometimes we flame out.

Hope this helps!