In 2011 Stafsjö was faced with a request from a well known international OEM supplier with a strong foundation within the Pulp and Paper Industry. They wanted a technically fast and reliable valve capable of operating within a broad range of pressures, pulp concentrations and temperatures. The develop ment team at Stafsjö got down to work and the story of the 20 bar rated HX valve began.
The production volume at pulp and paper mills across the globe are increased, new mills are being built capable of achieving new record production volumes and old plants are being converted or upgraded. As a knife gate valve supplier Stafsjö represents a part of the machinery equipment.
The Stafsjö HX knife gate valve ensures batch digester isolation during pulp stock production.
Read the story about HX severe service knife gate valve to see how it can help you improve production or find out more about the Stafsjö range of high pressure knife gate valves.
Stafsjö have released their new rubber valve seat compound FEPM for knife gate valve series WB11, WB14 and specifically for the full stainless steel high performance WB14E. The new rubber compound is currently available for DN 80/3” – DN 300/12” except for DN 125/5”.
The new FEPM seat material is an improved Viton/FKM based rubber compound that has superior function and strong resistance to high temperature steam and aggressive chemicals, both acids and bases. Pulp and paper and chemical industries are field of applications were the FEPM materials are well known and used on regular basis. FEPM rubber can be used as a direct replacement for the rubber trademark AFLAS which is a TFE/P FEPM material.
The seat is rated for max 180°C in continues service and short term peak up to 225°C. The compression set resistance at high temperatures is superior to other standard rubber materials, but it is limited in low temperature applications. Function tests shows that the FEPM material can give the sealing system considerably longer life time compared to standard rubber compounds. This makes the FEPM seat suitable for severe applications where you need a long-lasting performance and a tight shut-off.
New guiding pad material to WB14E: PTFE
In parallel with introduction of the FEPM seat material we also introduce PTFE guiding pads to WB14E up to DN 300/12” to replace standard POM-C in applications where it is needed to fulfil FEPM temperature and chemical resistance. The guiding pads are located in the chest area to prevent galling and to support the gate at pressure loads. These can easily be replaced at any maintenance work as well.
Contact one of our technical specialists today to see how we can help you extend the life of your knife gate valves, or download the WB14E brochure now.