SERVICES AND REPAIRS
In addition to fabrication of new exhaust systems, metal expansion joints, hose assemblies and distribution of various pipe motion products and diesel engine parts, Mark David Canada Inc. provides a range of services and repairs of your existing exhaust components.
REPAIRS

Bellows element is the most fragile component of any exhaust manifold or expansion joint. Bellows failures typically result from: excessive vibration, excessive thermal movement, inadequate cycle life design, internal or external corrosion, erosion, torsion, excessive pressure or temperature or mechanical damage.

Where cost effective, MDC will replace damaged bellows at a much lower price than replacing an entire section or joint.
EXAMPLE 1. – ALCO SECTION REPAIR
In this example, we identified the component as the Alco manifold section P/N 2283037 for the 6 cyl. engine. Bellows damage was determined to be the fault of original manufacturer.
Bellows element is made of multi-ply sheets of stainless steel and corrugated after the sheets are telescoped. Bellows are supposed to be heat treated after forming, so any moisture between the plies would be evacuated. This was not done prior to final assembly.
Once the system was in operation, moisture trapped between plies vaporized into steam and expanded, ballooning the bellows.
Mark David Canada Inc. maintains stock of Alco sections’ sub-components for purpose of our new manufacture and for repairs of customer’s sections. The bellows assembly shown here is used on all Alco 6 and 12 cylinder engine exhaust sections.
We receive the damaged manifold section and mount it on the welding fixture. The damaged bellows is cut out and replaced with a new one. Welding fixture ensures that all OEM dimensions are maintained during replacement process.
EXAMPLE 2. – BUS EXHAUST CONNECTOR REPAIR
Shown above, is a new assembly for bus exhaust application as supplied to the bus manufacturer. Mark David Canada Inc. services several clients who run fleets of municipal buses. The transit authority set out to lower the cost of exhaust element replacement by contracting us to replace the damaged bellows component only.
We cut out the damaged bellows sub-assembly from the exhaust connector when first received. We then proceed to analyze the existing bellows and determine the cause of failure.
The replacement bellows is designed to last longer than the original one. This is done by varying the corrugation height, corrugation pitch, number of plies or thickness of individual ply. The new design is verified by EJMA based computer program and a number of allowable cycles is determined. Calculations for the old bellows element are used as a baseline comparison.
RECONDITIONING

Where economical, MDC will recondition an entire assembly.
EXAMPLE 3. – GE MANIFOLD SECTIONS

MDC would receive an entire batch of damaged sections. Those with dents in the main body or bent arms are not considered for reconditioning. Typically, 75% of sections are suitable for the process.
The full scope of MDC reconditioning is as follows:
• Manifold sections are received and evaluated visually. Those with damage beyond the scope of reconditioning are set aside. The others are individually tagged to allow total control throughout the repair process.
• Sections are cleaned in chemical bath to remove soot and deposits.
• Pressure test is performed to determine body and bellows damage areas.
• Bellows + Liner sub-assembly is replaced.
• Bellows shroud is replaced (as needed).
• Dye pen verification (LPI) of all welds and other surfaces.
• Repair of body welds is performed (charge per inch of weld).
• Repair of flange welds is performed (charge per inch of weld).
• Glass pellet blasting of assemblies for uniform “as new” look.
• Final pressure hydro test.

Reconditioned manifold sections are subject to the same warranty conditions as newly manufactured parts.
EXAMPLE 4. – 12 CYL. MANIFOLD SECTIONS
Mark David Canada Inc. will replace the bellows element on any damaged manifold sections (such as shown above) for any engine brand.
EXAMPLE 5. – EXPANSION JOINT REPAIR OR REPLACEMENT
Mark David Canada Inc. will repair or produce a new expansion joint from a sample. The joint shown above was received from a merchant vessel of foreign manufacture. The bellows element and metric flanges were fabricated anew. A flow liner was added to the new assembly, since there were signs of erosion inside the failed unit.
SHIP SURVEY

MDC’s personnel will conduct a survey of your vessel’s piping system and identify all expansion joints, hose assemblies and insulation blankets. We can produce product drawings for future re-order reference and verify the condition of parts currently in service.

The engine room shown here, houses two 18-cyl. Alco engines.
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