Graph-Lock joint sealant is a stainless steel foil and carbon fibre reinforced yarn encapsulated in graphite. The Graph-Lock joint sealant material can be applied to a sealing face and joined with a skive cut, with gasket ribs made by overlapping joints and pressing together. On compression of the join sealant, a homogeneous mass forms at the joint providing a seal which can work at temperatures up to 1,000°C and pressures up to 310 bar.
The Graph-Lock join sealant avoids the need to remove the tube bundle as there is no need to pass the tubes through the gasket as with conventional metallic gaskets. Removal of the head and slackening of the tubesheet to access the shell seal face is generally all that is required, Garlock says.
Graph-Lock is highly compressible, does not harden or dry and can be re-used up to three or four times. Sections are available as square semi-round and rectangular with standard sizes ranging from 1/8 in square to 1 in x ¼ in and it is available in lengths of 8 m and 15 m.
Suitable applications for the Graph-Lock joint sealant from Garlock Sealing Technologies include shell and tube heat exchangers, particularly where they are positioned in confined spaces.