Valves for board machines

If top-reliability and high performance in the paper industry are your main concerns, we have the solutions. Metso provides a full range of top quality, on-off and control valves for applications ranging from wood handling and approach systems to the paper machine and finishing processes. Metso has been a pioneer in the paper business since the very beginning, which is why today most of the world's pulp flows through our valves. We have good references and satisfied customers in every part of the world. Our customers know that they can rely on us.

Energy consumption

The steam and condensate system is a part of the paper and board machine. Its purpose in the paper machine is to provide the steam for the drying. Final drying is carried out in the drying section. This is achieved by means of several steam-heated dryers (cylinders). These are driven in groups of a few together. The paper sheet runs over a large number of dryers and moisture is evaporated as the sheet is pressed between a fabric and the hot drying cylinder. The temperature of each of the dryer surfaces must be precisely controlled. The temperature is lower in the first groups of dryers and then raised slowly in the later groups at the end of the drying process.

Fast and accurate control

The biggest single expenditure in a paper and board mill is on energy consumption. That is why faultless valve operation has an important role in the steam and condensate system. Metso offers a wide choice of on-off and control valves for the steam and condensate system. Good tightness is a preferred feature for all steam valves. If accurate control is your concern, the R-series segment valve is the obvious choice. It will help you to adjust temperatures in the steam and condensate system fast and accurately, for example in a grade change situation. Furthermore, our cost-effective triple eccentric butterfly valves offer excellent tightness and good control properties for steam and condensate systems.

Steam and condensate handling

Due to elevated temperatures metal seated valves are used in this process. The valves used should provide certain minimum tightness levels. The steam valves have to close as the paper sheet brakes or for other short shut down reasons. Elevated temperature in the dryers may damage the fabrics. The collection of condensate harms the re-start and causes problems to the machine drives.
If the paper machine is to produce only one bulk paper grade, no big adjustments of the steam flow have to be made. Here a butterfly type valve can be successfully used as the control element if the system design data is calculated solid.
The basis weight and the steam consumption of the board machines must be changed often in large increments during the operation. The valves used for control purposes must provide a good controllability (rangeability).

Learn more about basis weight control

Basis weight control is one of the most critical applications for a valve in a paper machine. Metso nelesACE is the ultimate offering for this application. The unit consists of a reliable V-port segment valve, complete with a high-resolution step-motor-driven rotary actuator, limit switches, and potentiometer. The nelesACE control unit's unique feature to run valve with various step sizes, depending on error between actual and desired flow rate, makes it a superior element for basis weight control.