46 CFR §56.25-15

1. (a)Gaskets must be made of materials which are not injuriously affected by the fluid or by temperature.
2. (b)Each gasket must conform to the design requirements of the applicable standards of table 2 to § 56.60-1.
3. (c)Only metallic and suitable asbestos-free nonmetallic gaskets may be used on flat or raised face flanges if the expected normal operating pressure exceeds 720 psig or the operating temperature exceeds 750 °F.
4. (d)The use of metal and nonmetallic gaskets is not limited as to pressure provided the gasket materials are suitable for the maximum fluid temperatures.