Description:QS KammprofileTMGasket (Serrated Metallic Gasket) consist of a metal core, generally stainless steel with concentric grooves on both sides. A sealing layer is usually applied on either side and depending on the service duty the material for this layer can be expanded graphite, PTFE, Asbestos free gasket sheeting materials or some soft metal. It can be used without sealing layers to provide an excellent sealing but there is a risk of flange surface damage especially at high seating pressure.
3040 Basic Type Kammprofile Gasket
3040 JR Kammprofile Gasket with integral Outer Ring
3040 SJ Kammprofile Gasket with Loose Outer Ring
Depending on centering ring with cheaper material (Normal: CS) and thinner thickness (Normal: 1.5mm) for Style 3040 SJ, maybe it is more economical than 3040JR.