What is stick-pin insulation and when is it required?
Stick-pin insulation is a mechanical fastening method in which insulation boards or blankets are impaled on welded or self-adhesive metal pins and locked with speed-clips. PEC specifies it when surface temperatures, orientation, weight, or code requirements make adhesive-only systems unreliable—typical on exterior ductwork, large tanks, boilers, and high-temperature process equipment.
Stick-pin insulation, sometimes called “pin-weld” or “impale-and-cap” insulation, is widely used across food, chemical, and power plants where PEC installs mechanical insulation. After PEC’s technicians clean the metal surface, they weld or epoxy-bond 12-gauge steel pins on an 8–12-inch grid.
Fiberglass or mineral-wool boards are then pressed onto the pins and secured with locking washers before the excess pin is clipped off. This creates a positive mechanical hold that will not delaminate when equipment vibrates or cycles above 150 °F. Because the assembly does not rely on continuous adhesive coverage, it also minimizes corrosion-under-insulation risk by allowing the substrate to breathe.
Building and energy codes typically require stick-pin fastening on horizontal or overhead ductwork thicker than two inches, on outdoor ducts subject to wind shear, and on vessels, precipitators, or storage tanks where curved surfaces make banding difficult. PEC recommends the method whenever insulation weight exceeds ¾ lb per square foot or whenever operational temperatures approach the service limit of common mastics.
Using stick-pin insulation helps customers improve thermal efficiency, reduce heat loss, protect personnel from hot surfaces, and extend equipment life without costly shutdowns.