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Mönchengladbach & Hilchenbach, December 09, 2020

Shortest shutdowns for valve block general overhaul of high pressure hydraulic

Basis for securing long service lives and the long-term efficiency of plant and equipment

With valve blocks in rolling mills, in particular, it is necessary to keep an eye on any runtime-related wear that may affect the operation of the plant. That is what makes condition-based inspections and component upgrades indispensable.

To ensure the long-term efficiency of the valve blocks in their rolling mill, customers can rely on SMS group's modernization expertise. Experienced hydraulic experts guarantee not only a concept that is tailored to the hydraulic requirements but also short shutdown periods and first-class quality for repairs or upgrades to the valve block and individual components.

Causes of wear

Normal material wear causes valve blocks to leak over time. For example, O-rings can harden and become brittle, which may lead to the first leaks occurring after years in operation. The escaping oil may also attack the material over time. It is important to rely on hydraulic experts from the very beginning and not try to eliminate the leaks yourself first. Trouble-free operation for a further 10 years is usually guaranteed by having components reworked by SMS group in good time and eliminating the sources of faults. But what is the best way of avoiding a plant shutdown lasting several weeks?

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Dismantling and cleaning of valve stand sandwich blocks.
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O-Rings are hardened out and brittle.
Our concept for short shutdowns

In the case of rolling mills with several stands and four valve blocks per stand, preventive maintenance and a well-planned upgrade are crucial for a short shutdown of the whole plant. Experience gained from numerous projects in the past has shown that, with an upgrade as extensive as this, it pays for the customer to order a set of spare columns.

Dismounting of leaking valve blocks at customer site.

The spare colums are installed in the first stand during an initial brief shutdown or regular maintenance downtime. The valve columns are taken out and sent to one of SMS group's worldwide service workshops and professionally reworked there. The overhauled components can then be fitted in the next stand during a short shutdown and the set that is removed can be remachined by SMS group. This step is repeated until all valve blocks in all stands have been machined and replaced.

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Ready for shipment to SMS group workshop for overhaul.
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Removed and replaced parts at SMS group workshop in Hilchenbach.
General overhaul by SMS group hydraulic specialists

The work of our hydraulics experts in our workshops include:

  • Dismantling
  • Cleaning, inventory, condition assessment, checking of all tolerances
  • Replacement of all DIN and standard parts and valves
  • Assembly/installation
  • Flushing, testing and setting of valves (setting values from previous fact-finding review are adopted)
  • Optional test of the servo valves (hysteresis, offset, zero leak oil volume, etc.)
  • Painting
  • Shipment to the customer's works

This proven modernization concept means that the customer has a shutdown period of only a few hours per stand and the SMS group service workshops have sufficient time to carry out a comprehensive overhaul to OEM quality standards, including subsequent testing on one of SMS group's hydraulic test fields.

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At hydraulic test field in SMS group workshop in Hilchenbach: Adjusting of all functions according the previous set values.
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At customer site: Assembly, air bleeding, pressure testing and commissioning of high pressure hydraulic.

At the end of the extensive upgrade, the customer not only has valve blocks that are as good as new in all stands, but also has a fully overhauled set in stock.