Whenever a worn-out or damaged machinery component is too large to be brought to a machine shop, or when doing so involves too much dismantling work and thus is too time consuming and costly, then the solution is to bring the machine tools to the site. This is what in-situ machining is all about.
For several years, QuantiServ has been supporting machinery owners and operators from various industries such as marine, energy, petrochemical and oil and gas, to name a few, with cutting-edge in-situ machining services.
In twelve locations across the globe we have highly trained engineers who are able to respond and travel to a site within hours.
Click on one of the links below to learn more about how QuantiServ can help you to repair your equipment fast, economically and reliably.
Case Study
Background:
The timeline below shows, in chronological order, the individual steps that make up a comprehensive repair. It is an example of a typical repair assignment, carried out by two specialists from QuantiServ Sweden en route in South America at the end of 2020. Their task was to repair a crankpin bearing failure.
The subject of the repair was a 32 cm bore, 40 cm stroke auxiliary engine installed on a 5-year old 9’200 TEU container vessel. The customer asked us to carry out an inspection on board, which we did. He then decided to award the repair work to another company. That company commenced the repair, machined 0.80 mm off from the pin and then walked away from it, unable to continue. So the customer came back to us.
Timeline:
-
29.09.2020 - Service Enquiry
We receive the service enquiry from the ship owner’s office
-
30.09.2020 - Repair Proposal
The following day, we submit to the customer an offer for an inspection on board
-
08 - 09.10.2020 - Inspection
A specialist from QuantiServ Panama carries out a comprehensive inspection on board the vessel in Panama. The inspection takes two days.
-
13.10.2020 - Repair Proposal
Based on the results of the inspection, we submit a repair proposal to the customer.
-
- Competitor Starts and Then Abandons Repair
The customer awards the work to a well-known competitor of ours. The company machines the damaged crankpin to – 0.80 mm and then abandons the work due to their technical inability to complete the repair.
-
24.11.2020 - Customer Comes Back to Us
The customer comes back to us and asks us if we could finish the repair that was started by the other company. We agree and start to pack the tools and mobilize our specialists.
-
10 - 13.12.2020 - Engine Dismantling Work
Our repair plan foresees that all repair work is to be done during the voyage. Two specialists from QuantiServ Sweden board the vessel in Lima. First, they partly disassemble the engine to enable the repair. This takes 4 days.
-
14 - 16.12.2020 - In-situ Heat Treatment
The bearing failure has caused an unwanted increase in the crankshaft’s hardness. In-situ heat treatment solves this problem. It reduces the hardness from a maximum of 620 HB to a maximum of 255 HB and takes three days.
-
17. - 21.12.2020 - Crankpin Rough Machining
Cracks are found in the pin. We machine them out and carry out MPI crack testing repeatedly. This takes four days.
-
22.12.2020 - Straightening (Peening)
The bearing failure induced a lot of heat into the crankpin, causing the crankshaft to bend. We measure a run-out of 0.27 mm. In-situ peening reduces this to just 0.03 mm. It takes one day.
-
23. - 25.12.2020 - Crankpin Finish Machining
Accurately finish machining the pin to a diameter of – 3.00 mm takes three days.
-
26. - 28.12.2020 - Polishing
The next step after in-situ machining is machine polishing to achieve a mirror-like surface finish. Several crankpins and two main bearings get polished. This takes three days.
-
29.12. - 05.01.2021 - Engine Overhaul and Assembly
Assisted by the crew, our two specialists undertake overhaul and reassembly works for six days.
-
05.01.2021 - Assignment Completed
Our specialists successfully complete the assignment and disembark from the vessel in Mexico.
Result:
The repair of the damaged crankpin took eleven days to complete. Polishing of all six other crankpins and some main bearings took a further five days. The customer was very happy with the performanace of our two specialists and wanted them to lead the overhaul and engine reassembly until the spare parts available on board ran out and the work had to be stopped. All in all, our specialists worked on board for 25 days, from Lima, Peru, to Manzanillo, Mexico.
The customer was so happy with our performance that he asked us to supervise an overhaul of a similar engine on one of his sister vessels.
Photos:
Links
Crankshaft Machining and Polishing
QuantiServ’s in-situ technicians have decades worth of experience and are able to carry out any in-situ machining or polishing job fast, reliably and economically.
Crankshaft Straightening
As a consequence of severe overheating, a crankshaft – or indeed any shaft – may become bent. In many cases QuantiServ is able to straighten such a shaft in place without the need to dismantle it.
Heat Treatment (Annealing)
Local hard spots on the running surface are often created when a rotating shaft or crankshaft overheats. They are usually not permissible and have to be eliminated through in-situ heat treatment/annealing.
Laser Alignment
Alignment by laser is a very versatile, fast and accurate method. It ensures that critical parts, such as shaft lines and couplings, are perfectly aligned and will not wear out or fail due to vibrations or excessive stresses.
Line Boring
At QuantiServ we designed and built our own, very advanced portable machines that enable us to line bore any kind of equipment in almost any location. This greatly reduces dismantling time, saving precious time and money.
Installation of Sleeves and Bushes
QuantiServ excels in the fast and reliable installation of any kind of repair bush. A common example on four-stroke engines is to permanently stop jacket cooling water leaking into the crankcase by installing a repair bush in the engine block.
