Polyurethane foam insulation (PUR) is a rigid foam layer between the outside of the steel tube and the inside of the jacket tube. Polyurethane foam components are used to insulate joints: heat-shrinkable joints, electro-fusion welding joints, flexible elbow joints, open (plate type) joints, modified heat-shrinkable joints, end joints and reducting joints.
The PUR component set consists of:
Component “A” (POLYOL);
Component “B” (ISOCIONATE).
The total amount of components A + B is calculated corresponding to the filling of the heat-shrinkable joint according to the diameter of the joint. Component A and B standards are for L-440 mm insulated joints. Component mixing ratio: 1: 1.45 (kg).
When the components A (POLYOL) and B (ISOCIONATE) are mixed, a chemical reaction occurs, which fills, in the form of a rigid foam, the outer cavity of the steel tube and the inner cavity of jacket tube.