Four-stroke Cylinder Head Valve Seat Bore Repair

Our reconditioning centre in Vancouver has just carried out furnace brazing of 13 pieces of 32-bore four-stroke engine cylinder heads for Canada’s premier ferry operator.

The valve seat bores were seriously damaged by cavitation and corrosion. Machining to over-size was not possible anymore because this had already been done during past overhauls and the maximum diameter had already been reached.

QuantiServ’s unique process starts with the generous removal of any damaged material around the valve seat bores. Thereafter steel sleeves are soldered in in a vacuum oven before finishing off the heads by NC machining of the valve seat bores. Standard-size valve seats can then be installed, followed by pressure testing of each cylinder head.

QuantiServ’s furnace brazing process is applicable to four-stroke cylinder heads of any engine type with a cylinder bore diameter of > 200 mm. It is patented word-wide and classification approved (LR / ABS). Classification certificates are available on request.

Condition of the cylinder heads before reconditioning:

 

Condition of the cylinder heads after reconditioning, before installation of the valve seats:

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Two-stroke Bedplate Line Boring in Mexico

When a six year old bulk carrier suffered main bearing failures on its Japanese-made main engine, QuantiServ was called in for an initial inspection and for discussions on how to arrange the repair in the fastest and most economical way. The inspection in Veracruz, Mexico, showed that main bearings # 7 and 8 failed and that the crankshaft as well as the main bearing pockets were damaged.

The crankshaft was beyond repair and had to be replaced by a new one. The bed plate, on the other hand, could be recovered by line boring. With the engine frame lifted up, QuantiServ’s in-situ specialists carried out

  • a thorough inspection of the bedplate, including NDT crack detection and hardness measurements
  • laser alignment checks before line boring
  • line boring of main bearing pockets # 7 and 8
  • laser alignment checks after line boring
  • blueing checks

The work was carried out successfully while the vessel was alongside in the shipyard in Mexico.

Reconditioning of Two Large Hydraulic Rams in Singapore

Ram 2

In January 2018 our reconditioning centre in Singapore carried out the overhauling and reconditioning of two large hydraulic rams belonging to a major American offshore company. The rams are part of knuckle boom cranes that are installed on an ultra-deep water drill ship that operates off the coast of Myanmar.

We frequently perform this kind of work on rams large and small, often for offshore and construction companies.

The work included chemical stripping of the worn chromium layers, followed by new plating with an underlay of nickel and top-layer of chromium. We also honed the barrel, changed all seals and carried out various NDT tests on the rod and barrel.

All work was carried out in-house and was completed within 14 days.

At QuantiServ Singapore we are able to carry out galvanic nickel and hard-chrome plating and grinding of up to 6,000 mm length and 800 mm diameter.

Update April 2018:

The customer was very satisfied with the two rams that we overhauled for him in January 2018. In March he sent us another two similar ones belonging to the same ship. We have just finished the work on them, which means that we have now reconditioned all four units that are installed on this drill ship.

Reconditioning of Fourteen 96-bore Cylinder Covers

In November 2017, our Reconditioning Centre in Shanghai carried out reconditioning of fourteen cylinder covers for a major European ship owner. These covers came from one of the world’s largest container ships, equipped with a 14-cylinder, 96-bore main engine.

All fourteen cylinder covers and all fourteen exhaust valves were reconditioned within a period of less than one month, while the vessel was undergoing steel work at a shipyard in Qingdao.

This was the third vessel out of a series of similar vessels for the same customer. QuantiServ carried out the reconditioning work for all these vessels.

Significant Reconditioning and Field Service Job in Shanghai

In September our Reconditioning Centre in Shanghai carried out a a major reconditioning and field service order for an Iranian-owned tanker that was docked in a Chinese shipyard. This example shoes well the breadth of QuantiServ’s offering.

The following components were reconditioned:

  • 8 piston rods
  • 7 piston crowns
  • 7 cylinder covers
  • 6 exhaust valves
  • 7 crosshead pins
  • plus a number of smaller, related components

We also sourced for the customer a couple of new crosshead and crankpin bearings while we re-babbitted others, such as for example guide shoes.

QuantiServ engineers also carried out the overhaul work on board, supervised the oil flushing and attended the seatrial after the docking. We also replaced the stern tube shaft seals and in-situ polished some of the crankpin journals.

All the work was completed in 32 days.

Repair of Externally Damaged Cylinder Liners

Our reconditioning centre in the Netherlands has just completed the repair of yet another externally damaged cylinder liner. We carry out this kind of repair quite frequently.

External damage to a cylinder liner is usually caused by rough handling. Liners are made of cast iron and cast iron is brittle. If a liner is dropped on the floor or is otherwise handled roughly, then material may chip off. Most damages occur in the vicinity of the o-ring grooves, where the material is thin.

If such a liner has to be scraped, then it is obviously a big waste. This is why we frequently repair them. Typically, the repair costs amount to approximately 20% of the replacement costs.

The following pictures show three examples of such repairs on liners of different sizes: An 84-bore liner, a 72-bore one and a 60-bore one.

 

It’s All in a Month’s Work for QuantiServ’s In-situ Machining Crew!

On board various ships and oil rigs, in power plants and in factories: Far from being idle during the holiday season, during the month of July our in-situ specialists were maintaining and repairing our customers’ equipment in 26 different countries, across four continents. No other in-situ machining company has such global reach and completes more projects than QuantiServ. Wherever the location, whatever the damage – it’s all in a month’s work for us!

Explore the interactive map below and discover what services our in-situ engineers have been providing to our customers during the month of July 2017.

Flywheel Teeth Dentistry on a Container Ship in Hong Kong

 

Our in-situ specialists from QuantiServ Dubai have just completed another flywheel repair. This time it was for a very large European owner, on one of their large container ships with a 12-cylinder, 96-bore engine while on anchorage in Hong Kong. Our specialists machined off two damaged teeth and installed an insert, which they had pre-fabricated at their workshop before boarding the vessel and which they sent on board jointly with the in-situ tools.
The total work took 42 hours – three long days of work – and the result is something that they can be very proud of!

Damaged flywheel with two severely damaged teeth

Damaged flywheel with two severely damaged teeth

Removal of the damaged teeth by in-situ milling

Removal of the damaged teeth by in-situ milling

Pre-fabricated insert installed, repair completed

Pre-fabricated insert installed, repair completed

ABC Engineering Pte. Ltd. in Singapore joins QuantiServ

abc-logoWe are very honoured and happy to announce that all personnel from ABC Engineering Pte. Ltd. have decided to join QuantiServ with effect from 1 April 2017. This combination of forces further extends QuantiServ’s offering and geographical reach, particularly in Indonesia.

ABC Engineering is a well known company with excellent reputation that has been providing in-situ crankshaft and engine block repair services to customers in Southeast Asia since the 1970s.

The personnel from ABC Engineering and QuantiServ look forward to continue to serve ABC Engineering’s customers as reliably and to the same exacting standards as they always have.

Metal Stitching of an Engine Block in Tehran, Iran

 

Metal stitching on an auxiliary engine block

Our metal stitching expert traveled to Tehran, Iran, last week to repair a four-stroke main engine block on board a tug boat. It had a crack between the charge air space duct and the cooling water space around one of the cylinder liners, as well as some dents. Cooling water was leaking into the charge air space.

To repair the damage took our expert just one full day of work. The customer was very pleased with the result and was impressed by how fast the repair was being carried out.

Once again it was proved that metal stitching is a quick and reliable solution for cast iron repairs – for jobs big and small!

 

 

Enjoying a cup of tea in the engine room after a job well done

Enjoying a cup of tea in the engine room after a job well done

Metal stitching

A very happy customer

QuantiServ Singapore’s own wharf again able to accommodate vessels

Maintenance dredging at our own wharf in Singapore has just been completed. We are now again able to accommodate vessels of up to 110 meter length and 5.0 meter draft for repair, right next to our very well equipped 10,000 square meter workshop. It does not get any more convenient and economical than this!

Our very own wharf in Singapore, right next to our workshop.

Our newly dredged, very own wharf in Singapore, right next to our workshop.

 

In-situ machining of lateral surfaces on a 20V32 engine block in Bangladesh

Lateral surfaces before and after in-situ machining

Lateral surfaces before and after in-situ machining

In-situ machining of lateral surfaces on a 20V32 engine block in a power plant in Bangladesh

In October 2016, QuantiServ received an urgent request to carry out in-situ machining on a 20-cylinder 32-bore engine block in a power plant in Bangladesh. During the replacement of the crankshaft it was noticed that both lateral surfaces of main bearing cap number 5 showed signs of severe fretting and were in need of machining.

Immediately, in-situ machining equipment was prepared at QuantiServ’s Dubai workshop and was sent to site. Once the equipment had arrived at site, QuantiServ’s engineers from Dubai performed in-situ machining on the engine block to achieve a clean surface that was free from damage. The in-situ machining process was constantly monitored by laser to ensure perfect alignment and adherence to very tight machining tolerances.

The main bearing cap was sent to a local workshop in Bangladesh for machining and installation of compensation plates. This process was supervised by QuantiServ’s engineers. Once the machining was completed, all mating surfaces for the main bearing cap were checked with marker blue to ensure a perfect fit.

Once the work was completed, a final check by laser on the assembled bearing cap showed that both the bore alignment and diameter fully conformed to the engine maker’s specification.

In-situ flywheel repair on a 3400 TEU container vessel in Mombasa, Kenya

milling-and-tapping-quantiserv

Milling and tapping, preparation for the teeth inserts to be installed

In-situ flywheel repair on a 3400 TEU container vessel in Mombasa, Kenya

QuantiServ received a request from a customer to repair the serration on a main engine flywheel. The vessel called Dubai, where QuantiServ engineers carried out an inspection. They found that five teeth were missing; an isolated one and four in a row.

While the vessel continued her voyage to Africa, our technicians manufactured new teeth and fitted bolts at our workshop in Dubai. They then brought these jointly with the required in-situ machine tools to the vessel, which had meanwhile reached the port of Mombasa in Kenya. There, the machining and installation work was carried out by four engineers in two shifts, around the clock, while the vessel was undergoing cargo operations.

Prefabricated teeth and fitting bolts

Prefabricated teeth and fitting bolts

The work was completed successfully within a tight time window of 72 hours without delaying or otherwise interfering with the vessel’s normal sailing schedule.

The final result, five missing teeth replaced

The final result, five missing teeth replaced