Up and Running articles
Up and Running articles
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Safe and efficient calender roll removal - four methods
These methods of calender roll removal are recommended by Valmet. Other methods may be used, depending on style/size of calender & available lifting equipment.
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Hot water modules for calender rolls, recommended maintenance
Calender rolls are heated via heating modules to provide low-variance accurate roll temperatures. Follow these hot water module maintenance best practices.
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10 tips: Resist headbox corrosion in maintenance & operation
Corrosion can be minimized by adhering to these maintenance and operating procedures.
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Common hydraulic valves – cartridge counterbalance valves
Counterbalance valves prevent oil from leaving a cylinder that is holding a load. Without them, loads would move uncontrollably if oil pressure is lost.
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Common hydraulic valves - the proportional pressure valve
Proportional valves are commonly used to control pressure to a cylinder or hydraulic motor.
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SymRoll troubleshooting - leakage, cover wear and vibration
For troublefree function of SymRolls, the following are troubleshooting and maintenance tips and procedures regarding oil leakage, hydraulic and pneumatic systems, roll cover wear, roll vibration and other roll change factors.
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SymRoll recommended maintenance - End seals & roll overhauls
For trouble-free functioning of SymRolls, the following are recommended maintenance regarding the end roll seals and overhauls (complete or regular operation).
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Knowledge and technology drive Valmet roll cover development
It is just as important to optimize the structural design of covers as the choice of materials. This has been, and will continue to be, a tough but interesting challenge, since the requirements of the papermaking process often exceed the demands of any other industry.
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Troubleshooting chronic wrinkling on a size press, case study
Valmet investigated an issue where a size press was having wrinkling when the nip closed and before the applicator beam was loaded. The culprit was hydraulic.
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Reel audit leads to increased tonnage on fine paper machine
Audit recommendations included replacing a carrying roll with a driven bowed spreader roll. This decreased broke due to winkles, adding 18 tons/day production.