Exhaust Pipe Suspension for Marine and Offshore Applications

Engines are vital for generating power in marine and offshore environments, but they also produce significant vibrations and noise, which can lead to long-term structural damage and negatively impact onboard safety and comfort. One important aspect to consider is the suspension of the exhaust pipe to prevent such issues.

Vibration isolation is essential to mitigate these issues, enhancing the performance and durability of equipment while reducing environmental noise.

With a long history of working as a subcontractor for Scandinavian shipyards and engine suppliers, Vibratec has expanded its expertise globally. Our solutions range from exhaust noise reduction to the protection of sensitive equipment.

Our goal is to be the go-to provider for noise, vibration, and shock reduction in marine and offshore applications.

Example: Elastic exhaust pipe suspension with Vibratec products

For clarity, the following example is illustrated with a principal sketch.

Elastic fix points

Starting at the bottom of the example image, the pipe is fixed above the engine turbo charger using two VTCI-serie isolators and one machine mount. The machine mount is placed to ensure that the pipe expansion is directed away from the engine, thus the turbo charger will not be damaged by the reaction forces from the next expansion joint.

Optimizing the solution to reduce dynamic Issues

Since the pressure pulsations are strongest near the engine, it is advisable to make the first pipe section as long and heavy as possible to avoid a dynamic problem.

For this reason, the next coming expansion joint should be located as far away from the engine as possible.

To minimize the reaction forces acting on the mounts, we recommend that all expansion joints are as soft and flexible as possible, and are exposed to primarily axial movement.

The pipe clamp provides stabilisation, vibration isolation and guarantees free thermal expansion.

Stabilizing the silencer and ensuring secure suspension

In the present example, we have chosen to fix the silencer with VTCI-isolators and stabilise the pipe above the silencers with three pendulum isolators. If this support point is located near passenger areas, low frequency isolators (spring hangers) are a recommended.

Finally, the pipe passes through a clamp at the top of the funnel, a sealing cap provides a rain proof passage above the clamp.

Vibration Isolation of Exhaust Pipes

Rigidly suspending exhaust pipes on ships is an outdated method. Modern shipowners now recognize the importance of flexible mounting systems, which prevent vibrations from transmitting to the ship’s structure (structure-borne noise).

The benefits of flexible pipe suspension include:

• Significant reduction of onboard noise levels
• Prevention of deformation in exhaust components caused by rigid mounts
• Elimination of certain expansion joints, as flexible mounts allow for free expansion

Principles of Flexible Pipe Suspensions

The key to effective flexible suspension is carefully selecting specific points where pipe movement needs to be restricted. At these points, relatively stiff mounts, such as Vibratec’s VTCI-series isolators, are used as “fix points” to control movement.

Common positions of suspension points include:

• On silencers and other heavy equipment
• Immediately after the engine turbocharger
• At sharp pipe bends

Elsewhere, stabilize the pipe and still allow free expansion. Depending on the pipe’s orientation and surrounding structure, stabilization can be achieved using our:

• Pendulum mounts with isolators (Figure 1)
• Slide-mounted isolators (Figure 2)
• Pipe clamps with resilient metal cushions (Figure 3)

Advantages with Vibratec’s Mounting Systems

Since the 1980s, thousands of vessels have used Vibratec’s mounting solutions. Our success comes from engineering products specifically for their applications. Because we make our isolators entirely of metal, they withstand the high temperatures typically found in exhaust systems. This durability ensures our systems last as long as the equipment they support and rarely require replacement.

Our all-metal elastic systems accommodate thermal expansion while isolating vibrations. Vibratec offers complete solutions for flexible exhaust suspension, including detailed technical proposals tailored to each customer’s needs.

Required Data for Technical Proposals

To create a comprehensive technical proposal, we require the following information from the shipyard:

• CAD-drawings showing the pipe routing and surrounding structure
• Pipe material, diameter, and thickness
• Weight of additional heavy equipment such as silencers, boilers and valves
• Technical data for any included expansion bellows

If you have any further questions please feel free to contact us at Vibratec

Use the contact form on our website or contact our sales team below. We look forward to connecting with you and your team!