Phelps Style 9001 is a spiral wound metal gasket for LMF (Large Male Female) flanges, and is only available for ASME 16.50 flanges. Compression of the sealing element is controlled by the use of the correct flange face configuration - therefore, spiral wound gaskets are recommended for tongue and groove, male and female and flat to groove flanges only.

In the case of LMG flanges, the depth of female recessed-face is normally equal to or less than height of male raised-face to prevent metal-to-metal contact during gasket compression