Tag Archives: re-engineering

Engineered Services: Re-engineering increases Recip Compressor Lifetime

Re-engineering has increased the reliability of reciprocating compressor cylinders and allowed our customer to increase production. The cylinders are part of ammonia gas (NH3) compressors that originate from the 1960’s. Over time, the ammonia gas has deteriorated the cylinders. The valve seats have been damaged and because of that the reliability of the machine could not be granted.

New cylinders for this compressor were not available. To keep the compressors running, the customer contacted Maintenance Partners.

Customer Request: Extend Lifetime at increased production

Our customer did not only ask us to renew the cylinders, but also asked to extend the lifetime at an increased level of production. This question fits seamlessly with our vision of Engineered Services maintenance and reliability solutions for rotating equipment are the foundation for improving reliability, output and efficiency of the production process.


Study of materials
MP’s engineering department first performed a re-engineering study to define the opportunities for improvement. The first step was an extensive material study to determine which material was the most fitting for the customer’s demand. The new material had to be able to resist the product and an increased pressure, allowing for the increase in durability.

Afterwards, the existing compressor was fully scanned in 3D, after which technical drawings were made. The drawings were used to make a casting model and draw up the casting procedure. The pieces were cast by an external supplier.


The castings were checked for dimensions and any casting errors. Our engineering department created the necessary procedures for machining the castings and special tools were developed for the machining.
In MP’s workshop, the castings were machined by the Tos Varnsdorf boring machine. A CNC controlled head was used to machine the inside of cylinders.

Quality check – Pressure Testing

When the machining was finished, each cylinder was tested at cooling water presssure (16 bar) and tested at process pressure (162 bar). After the pressure tests, the cylinders were transported to the customer for installation onsite by MP’s field teams.

Benefits for Customer

Thanks to the re-engineering of the cylinders, the compressors have been fully adapted to the customer’s process and product. Moreover, the reliability is also guaranteed at an increased pressure and production.


Contact us

Do you want to know how re-engineering can improve the reliability and output of your machines? Contact us at +32(0)3 541 71 40 or send us a message using the form below:

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    Over 7% efficiency increase after abradable sealing modification on GHH axial/radial air compressor

    Maintenance Partners - Abradable Sealing Upgrade - GHH Axial Air Compressor - 3D Scanning of Rotor for re-engineering 920Maintenance Partners has recently applied an abradable sealing modification to a GHH axial/radial air compressor in combination with one expander wheel. The compressor is used in a nitric acid train of a Turkish fertilizer plant. This upgrade has resulted in an efficiency increase of 7,36%. Our customer faced a growing demand for fertilizer products and contacted us to increase the efficiency of a GHH axial/radial air compressor.

    The GHH axial/radial compressor runs at 5250 RPM and was manufactured in 1967. The compressor has been running for almost 50 years and is one of the plant’s most critical machines for the production of various nitrogen- and urea based fertilizer products.


    Abradable Sealing Modification

    A turbo compressor’s overall efficiency is greatly influenced by the internal recirculation of the compressor gas, or Internal Recycle Flow. To solve this, Maintenance Partners offers a modified sealing system on the radial impeller balance piston location to significantly reduce internal recirculation.

    Maintenance Partners - Abradable Sealing Upgrade - GHH Axial Air Compressor A 920The reduction in recycle flow is the result of minimizing the clearances between the labyrinth and the rotor. This is achieved by removing the existing stator labyrinths, installing new labyrinth seal strips on rotor parts and installing abradable seal rings in the casing on impeller eye and balance piston location.

    All parts required for the modification were re-engineered and manufactured by Maintenance Partners.

    The new sealing system was installed onsite during a planned three-week shutdown of the fertilizer plant. During the installation, the team found severe alignment problems which lead to high vibrations. The rotor was re-aligned which solved vibration problems.

    As the compressor was partly disassembled during the shutdown, the occasion was utilized to scan the blade carrier in 3d for re-engineering and manufacturing later.

    Other improvements:

    Coating of rotor

    Besides the application of the abradable sealing system, the rotor was also coated (radial impeller & axial blades) to be protected against corrosion and to reduce fouling. The coating used is an aluminium filled chromate / phosphate bond coating that can withstand temperatures up to 260 °C.

    This specific coating has a very smooth surface that contributes to performance improvement and fouling rate reduction.Maintenance Partners - Abradable Sealing Upgrade - GHH Axial Air Compressor rotor high speed balancing 920

    250kW Booster fan becomes optional

    To increase flow, the compressor’s inlet was fitted with 250kW booster fan in the past. Thanks to the abradable sealing modification, the booster fan is no longer required and can be shut off, allowing our customer to reduce electricity consumption. The plant is operating 24/7 all year round this means that an energy reduction of 2 190 000 kWh per year can be achieved (250kW * 24 hours * 365 days) when the booster fan is not in use.


    Result for customer: Significant Production Increase

    Measurements conducted and provided by our customer show an efficiency increase of 7,36% after the abradable sealing modification. This increase results in an increase of discharge flow from 89 134m³/hour to 95 700m³/hour. The discharge flow measurements were taken at the same inlet temperature and running speeds:

    RUNNING SPEED RPM 5250 5250
    DISCHARGE FLOW m3/h 89.134 95.700 7,36%

    As shown in the table above, the modification has allowed our customer to increase production significantly without altering the operating parameters of the compressor or its driver. In addition, our customer was even able to reduce energy consumption as the booster fan is not required anymore.

    Needless to say, our customer is very happy with the results, as the maintenance manager’s quote shows:

    “We are grateful for your improvements to our compressor which is of great interest to us”

    Moreover, there is room left for further improvement to the compressor, as the current discharge flow increase was achieved without altering the blade carriers.


    Contact us

    Are you interested in compressor upgrades to increase output or reduce energy consumption? Call us at +32 (0) 3 541 71 40 or send us a message:

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      12-day Pit Stop Overhaul of Thermodyn Steam Turbine, Gearbox & Generator

      A waste to energy plant selected MP for the major overhaul of a 18MW Thermodyn steam turbine. Maintenance Partners’ short lead time and the ability to take care of the entire shaft (steam turbine, gearbox and generator) convinced the customer to award the contract to MP.

      12-day Pit Stop steam turbine overhaul

      Careful planning of works onsite and preparations in MP’s workshop allowed for a significant reduction of time needed to complete the major overhaul. Only 12 calendar days were required from turning gear to turning gear. Teams of 6 specialists worked 24/7 on the overhaul to ensure that the job was finished in time.


      The original scope included a major overhaul of the steam turbine, gearbox and generator. In addition, the steam turbine rotor also required high speed balancing.

      Earlier inspections showed that the spindle and bushing had to be replaced. To ensure availability of the material, all raw material was ordered in advance. After disassembly, MP’s engineers re-engineered the spindle and bushing and the parts were manufactured in the workshop.

      During the major overhaul, damage to four valve seats was found. The damaged valve seats were exchanged. Besides this, the final (low pressure) blade stage was damaged. The blades were repaired by welding in MP’s workshop.

      The exchange and repairs were completed without any delays in the 12-day planning.Maintenance Partners 18MW Thermodyn Steam Turbine Major Overhaul - Rotor HSB 920

      Result – Innovation Plan

      Thanks to the 12-day pit stop overhaul, our customer’s production losses were kept to a minimum. The customer was very satisfied with the works performed and has awarded MP a technical call out agreement for future interventions.

      To improve the steam turbine’s reliability, the customer and MP are cooperatively working on an innovation plan for the availability improvement of the Thermodyn steam turbine.

      In order to achieve the improvements, Maintenance Partners will use its Engineered Services to evaluate all aspects of the machine and determine were improvements can be made.

      Contact us

      Are you interested in 12-day pit stop overhauls for your steam turbines? Call us at +32(0)3 541 7140 or send us a message:

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        Acquisition of the company Blokland

        Maintenance Partners has the pleasure to announce the acquisition of the company Blokland.

        Blokland is specialized in re-engineering and the production of precision parts and mechanical devices. The company employs 5 people.

        Blokland is a dynamic company and is – thanks to their experience of many years – a technical asset for Maintenance Partners.

        We want to welcome all employees of Blokland and we are convinced we will start a successful cooperation.