Exhaust & Diverter Services

Maintenance

When considering an upgrade, a simple maintenance check or a continuous maintenance program, NEM can provide a comprehensive selection of on-site inspections, survey and testing services. Standard tasks can easily be performed by local personnel following the comprehensive instructions provided in the manuals and guidelines.

We recommend that our specialists conduct regularly scheduled overhauls of exhaust gas bypass systems equipped with diverter dampers, guillotines and safety-related dampers.

Our specialists are available to support all field services, in order to secure tight outage schedules, while meeting the operator’s requirements for quality and reliability.

Pre-outage assessments ensure on-time installation of required spare and wear materials, while minimizing the shut-down period of the system. Every service advisory support is completed with a functional test, comprising a proper work record including a final acceptance protocol.

Upgrade

Conversions & Retrofit Installations

NEM has broad experience where it comes to retrofit installations regarding enhancement and modernization of the functionality and flexibility of your system. Customized solutions are worked out in close cooperation with the client in order to meet any special, project-specific requirements. For example:

• Conversions of gas turbine simple cycle exhaust systems to combined cycle operation
• Installation of shut-off devices, such as guillotines, louvers and stack dampers
• Consultancy when it comes to the ideal damper positioning, questions regarding tightness and/or actuation principles

In order to support our clients in obtaining greater operational flexibility of their existing plants, e.g. to cope with quick and fast peak load demands, we even plan complete bypass stack retrofit installations, considering existing configurations with possible space constrains.

Replacement

Combined Cycle Exhaust
Gas Bypass Systems with Diverters

Exhaust gas bypass systems contribute operational flexibility, efficiency and safety to a combined cycle power island. The heart of any bypass system is the diverter damper. NEM diverter dampers combine state-of-the art design principles and technology with more than seventy years of experience and empirical field data.

The result is that NEM diverters have earned a reputation as the safest and most reliable dampers in the industry. While based on a high degree of standardization, diverters can also be custom-engineered to meet the specific combustion turbines characteristics, as well as the project’s individual requirements.

The stacks in particular are always designed to project specifications, such as height, design codes, acoustic requirements, environmental loads and applicable aviation warning regulations.

Advantages of the NEM-designed Bypass systems with diverters are:

• Interfaces designed for seamless integration between power island components, based on extensive gas turbines knowledge and HRSG experience
• High degree of standardization, resulting in lower costs and faster delivery, yet still flexible enough to allow for customized adaptions to individual project specifications
• Fully integrated control functions that allow for local or remote operation
• Proven maintenance-free double lamella seal for gas-tight closing of the diverter
• Reliable, easy to maintain sealing forces, thanks to diverter toggle arm kinematics
• Low seal air requirements with minimal effect on the heat balance, resulting in lower aux. power consumption
• Diverter cylinder/linkage arrangement designed to compensate construction and erection tolerances
• High degree of pre-assembly, resulting in easy on site set-up and commissioning
• Flexible operations through open/close, stepwise modulation and fast emergency closing duty
• Standardized round stack silencer design for lighter weights, increased structural stability and lower cost

Spare Parts

NEM is dedicated to providing customers with the highest-quality replacement parts, delivered in a timely manner.

The range of spare and wear parts covers, but is not limited to, seals, gaskets, filters, bearings, motors, actuator parts, aircraft warning lights, expansion joints, and many more components, such as customized fabricated damper parts.

As a leading OEM, we have unique relationships with equipment vendors, allowing us to secure the best quality and overall value for replacement parts.