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

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.

QuantiServ unveils its brand new, centreless facing machine

Months of design and development work came to culmination last week at a dry dock in Marseille, France, when QuantiServ’s new, state-of-of-the art surface facing machine was deployed into the field for the very first time. The machine is designed for in-situ milling and grinding of large, circular surfaces such as those found on large thrusters and well inserts, on slewing rings, hydro turbines, and on blast furnaces. Its first assignment was on the steerable thrusters and well inserts of a cruise ship.

The machine is highly versatile and able to machine surfaces that are vertical, horizontal or inverted. It is ideal to machine circular surfaces between 1500 mm and 5000 mm diameter.

The main advantage of this machine is that it is centreless. The machining head is supported very near to the surface that is to be machined. Thus, the cantilever-effect, which always occurs on traditional facing machines with a central pivot system and that negatively impacts their accuracy, is completely eliminated.

Surfaces that are not circular but rectangular or square shaped, are better suited to X-Y milling and grinding, which QuantiServ also offers.

Getting the machine ready for action at the bottom of the drydock

Getting the machine ready for action at the bottom of the drydock

Metal stitching test piece resists water pressure of 12 bars

Metal stitching test piece resists water pressure of 12 bars

Metal stitching, as long as it is carefully and properly carried out by trained technicians, is tight against gases and liquids. To demonstrate this, QuantiServ has manufactured two cast iron half-shells and has joined them together by metal stitching. The resulting container was successfully pressurized to 12 bars (175 psi) and no leak was observed.

This proves that there is no issue to repair cooling water spaces in for example engine blocks, where the cooling water pressure typically lies around 3 – 4 bars (44 – 58 psi), by metal stitching. In fact we knew this well, because we have done it successfully many times. But that the stitching could easily withstand 12 bars impressed even us.

 

 

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

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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

Rudder stem housing in-Situ Machining on a new type of LNG carrier

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Laser alignment of the rudder stem housing

Rudder stem housing in-situ machining on a new type of LNG carrier

QuantiServ have a long-term and good cooperation with many newbuilding and repair shipyards.

Recently QuantiServ were requested to carry out in-situ machining (line boring) of a rudder stem housing on a new type of LNG carrier that is under construction in a Chinese shipyard. Our team were on-board to calibrate the inner diameter of the rudder stem housing and found that the ovality and parallelism were out of limit.

Thereafter, a laser alignment check of the rudder stem housing was done and the corrections to be made were calculated. Finally in-situ line boring of the rudder stem housing was carried out successfully.

In-situ line boring of rudder stem housing

In-situ line boring of the rudder stem housing

A final check showed that the ovality, parallelism, roughness and centre line of the rudder stem housing were all within tolerance. The shipyard was very satisfied with our service and confirmed the final result.