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Yes. If it is 6 inches in diameter or greater, it is a pressure vessel. Johnny Pellin

Yes. The balance line is also needed to lower the pressure on one of the compressor shaft seals. Johnny Pellin

Bearing failure or bearing wear causing internal rubs on end wall. Fouling caused by inlet filter failure. Johnny Pellin

There are many options for the pivot on the back of the pad. The most common would be a button design with the button being a much smaller curvature than the bore it rests on. This is essentially a point contact which allows the pad to pivot in any direction. That point contact will tend to...

There is a setting within the governor / tachometer / OST system for the probes that are looking at that toothed wheel. I think it might be called gain. We changed this setting and altered the probe air gap to solve a buggy speed indication problem on a large steam turbine. All square toothed...

What is the tooth profile. In my experience, turbine manufacturers make toothed wheels with a square tooth design. The manufacturers of the governors and overspeed trip systems expect a gear tooth profile. This makes the system extremely sensitive to air gap. Johnny Pellin

On condensing steam turbines, it is common to use the leakage from the high pressure packing to supply the sealing steam to the low pressure packing. If the leakage is not sufficient to maintain about 3 psi, a regulator will introduce low pressure steam. If the leakage from the high pressure...

I agree that resonance is the most likely cause. We have successfully mitigated this type of vibration on vertical motors driving vertical pumps by adding a tuned mass damper. Basically, we clamped a piece a steel bar stock to the motor and tuned it by changing the length and adding weights to...

It is not so simple. I have seen recip and centrifugal machines run to destruction from liquid even with well designed suction piping. Process conditions, machine design and piping design are all important. Johnny Pellin

Too little information provided. Could be the electronic governor. Could be the I/P converter. Could be the hydraulic actuator. Could be the linkage. Could be the valve rack. Could be a worn out turbine. Could be steam conditions. Johnny Pellin

If everything is symmetrical, the net thrust should be close to zero. The thrust bearing requires clearance, set when it is cold. When the thrust bearing heats up in operation, it needs room for thermal growth of the bearing and associated hardware. Johnny Pellin

I have seen machines of this type experience elevated vibration as a result of increased radial bearing clearance, impeller rubs and cracked vanes. A detailed analysis of the vibration should help distinguish between these causes. The analyst may want to capture a coast down to compare the...

Does the bearing housing have a jam bolt coming down from the top, locking the bearing in place in the lower housing? If so, the fit between the bearing OD and the housing is less important. You could lap the bearing into the lower housing to restore the contact and re-babbit the bore. Of...

If you have to replace the first stage impeller to repair the damage, install an impeller with a higher NPSHr which results in a lower suction specific speed. I have used this exact solution for this exact problem on this exact service and proven over 30 years that the solution worked...

It looks like some of this leakage was coming from the point where the gland gasket (oring) crosses the casing gasket (Garlock or similar). This is a difficult spot to seal. Proper procedures for cutting the casing gasket at the face of the stuffing box is critical. Make sure you have...

Decoking water pumps typically operate in a batch process. The pump is cycled from Fill (lower head, high flow), Cut (rated flow, high head) and Recirc (low flow, very high head). The damage is probably occurring when the the pump is recirculating to the tank for bit switching. You can either...

We call this arrangement ball/sleeve. It is common and has worked very well for us on many pumps. This arrangement allows for the advantage of a sleeve bearing without use of a circulating oil system. This combination can be lubricated with oil rings and constant level oilers. Upgrading to a...

If the coupling is flexible, it can be pre-stretched to allow for thermal growth. If it is rigidly coupled, the driver machine is usually not sensitive to axial thermal growth. Johnny Pellin

As a general rule, it is usually preferred to have a rotating shaft in tension, rather than compression. Placing the thrust bearing at the top accomplishes this. Many vertical motors are driving vertical pumps. Some vertical pumps have a lot of weight supported on the motor thrust bearing...

You did not mention how the vibration amplitude changes with speed. But, run speed vibration with a round orbit and constant phase angle following repair suggests run-out or balance. The vibration is highest on the end where the wear ring was replaced. I suspect that wear ring is not concentric...