Let M&B Help You with your Maintenance Problems



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Engineering Services:

- Vibration Analysis

- Machinery Balancing

- Modal & ODS Analysis

- Modal Gallery

- Outages/Inspection

- Shaft Alignment

- Optical Alignment

- Thermal Growth

- PdM Programs / Vibration Surveys

- Motor Testing

- Thermography

- Lubrication

- Instrumentation

- Verification Services

Vibration Analyst Training

More Training:

- Vib. Fundamentals

- Machinery Balancing

- Advanced Diagnostics

- Practical Oil Analysis

- Shaft Alignment

- Optical Alignment

- Optical Alignment for Roll & Paper Machinery

- 3500 Monitors

- Training Schedule

- Course Fees




2005  - 2015
M&B Engineered Solutions, Inc.
All rights reserved.

Internal / bore alignment of

Reciprocating Compressors & Engines




 Optical Measurements.

M&B engineers have extensive alignment experience on nearly every class of machine. We are one of the few vendors who can provide quality optical measurement services. These two specific areas are required to provide you with accurate operating machinery alignment. We can identify and help you quickly correct existing problems caused by misalignment, and problems related to foundations, baseplates and piping. We can also provide your staff with specialized alignment training to improve their skills and increase your reliability.

The alignment between main bearing saddles, crosshead guides to cylinder bore and the perpendicular relationship between the main bearing centerline and crosshead centerline can be easily verified using optical measurement techniques. These checks would normally be performed during new unit installation prior to grouting, for evaluation after equipment failures, or during re-grouting of older existing equipment.

The optical system used consists of target centering devices holding wire crosshair or glass pattern targets and a precision line scope. A main bearing saddle alignment check is performed with the crankshaft and bearings removed. If the check is being prformed prior to initial grouting or re-grouting of an existing unit, the crankcase is first leveled. This leveling operation may also be quickly and easily performed using optical measurement techniques.

The optical line scope is mounted on a universal adjusting bracket fastened to one end of the crankcase. Targets are centered in each main bearing saddle. Typically, the telescope is adjusted to the axis defined by the first and last bearing saddle target. Intermediate targets are then viewed, and their deviation from the line of sight is recorded.

The same optical tooling system is used to measure the alignment relationship between crosshead guide centerline and cylinder centerline. For this alignment check, the optical line scope is mounted on the cylinder head, and targets are centered in each end of the crosshead guide and cylinder liner. The relationship of the cylinder centerline is compared with the crosshead guide centerline. Of course, the piston, piston rod, crosshead and connecting rod are removed for this check. In some cases, the connecting rod may remain in place.

Through the use of a special telescope, termed an optical transit square, the perpendicular relationship between the main bearing saddle centerline and crosshead guide centerline may be verified. The transit square is really two telescopes in one, with two focusing scopes built together at precise right angles. Centering targets are located in the first and last main bearing saddle and at each end of the crosshead guide. One line of sight is established through the bearing saddle targets, while the cross scope views the targets located in the crosshead guide. The deviation recorded on the crosshead guide targets is a direct measurement of the perpendicular relationship between the two centerlines

Lack of perpendicularity would most likely indicate a machining error or poorly positioned crankcase and bedsections. A twisted or out of level crankcase can drastically affect crosshead and cylinder perpendicularity. Therefore, on cases not yet grouted, this check should be performed after the crankcase and bedsections are established in a level position


. A typical alignment project might consist of:

  • Inspection of machinery baseplate and foundation

  • Shaft & coupling hub inspection and runout checks

  • Piping strain measurements & correction

  • Soft-foot measurement & correction

  • Measurement of the shaft alignment

  • Determination & implementation of
     required machinery moves

  • Final report and alignment drawings


Whether the job calls for laser alignment, reverse-dial indicators, or rim & face measurements, M&B can get your machinery precisely aligned and back in service quickly.


Dimensional Inspection
The dimensional inspection of a reciprocating compressor consists of the following procedures:
- Verify the straightness of the crankshaft bores horizontally and vertically in respect to gravity.

- Confirm the perpendicularity of the bores housed in each bay relative to the crankshaft.

- Principal inspection of the crosshead assembly before installation into the casing.
- Concluding inspection of the crosshead after installation into the casing.

- Confirmation of the distance of the crosshead below the centerline of each bay relative to the bores.





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Machinery Installation & Setup

If you are installing new or refurbished machinery, or undergoing significant repairs, M&B engineers can assist you with a variety of tasks to get your work done on time and with a focus on ensuring long-term machinery reliability and operability.

Utilizing the optical tooling and techniques mentioned above, we can help you:

  • Inspect / level machinery soleplates within +/- 0.001"

  • Inspect / level machine casings within +/- 0.001"

  • Monitor long-term elevations of installed foundations for settling

We also have standard construction / surveying instrumentation and experience, to assist you with:

  • Foundation layout

  • Marking / checking hold-down bolt locations before pouring

  • Elevation studies

M&B engineers can assist you with nearly every phase of your machinery alignment. And as always, our focus is on your long term reliability and operability. If you have questions, or an application that is not mentioned above, please call us to discuss your needs.

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