The big problem with spiral-wounds is you'll need a inner ring to prevent the windings from buckling. The outer ring on spiral-wounds also prevents winding buckling, but this is typically not need if your exchanger flanges are a confined type, which serves the same purpose for a spiral-wound gasket. If you're dealing with floating head covers on a straight tube bundle, you'll need a larger floating head to accommodate a spiral-wound gasket with inner ring, which increases overall cost & may require your shell cover to be built larger as well. If you have existing double-jacketed gaskets in any exchanger girth flanges or floating head flanges, I'd recommend upgrading them to kammpro gaskets