Intermittent Malfunction of Hydraulic Valve
Intermittent variations or drifts in the operation of hydraulic components on a paper winder dramatically increase the probability of inducing internal roll defects.
Such variations can occur sporadically, making them almost impossible to detect in the absence of a high resolution data acquisition and automated continuous analysis of pressure stability.
Among the 450 KPIs calculated on every production cycle (approx. every 10 min.), the Counter Pressure Deviation KPI enables us to detect rapidly changing pressure variations.
In this specific case, wild pressure variations were intermittently occurring for few seconds during the acceleration period.
The SPN continuous and automated data analysis system alerted the mill and triggered our experts’ attention.
Further diagnostic revealed that these variations were severe enough to negatively impact the drum speed differential and sheet tension stability.
A report was sent to the mill with specific recommendation to service or replace the counter pressure relief valve. A list of the suspicious sets (rolls) was also provided to isolate the potentially defective rolls and to avoid sending them to clients until they can be verified for defects.
Detection of this intermittent issue allowed the mill to limit the production of defective rolls and avoid shipping them to the customer.
Without the SPN continuous analysis service, this issue could have gone undetected resulting in significant losses due to defective products and deterioration of client satisfaction.