Nodular Iron, Cast Iron, Aluminum, and Copper Based Alloy Valves

  1. Nodular (ductile) iron valves, either austenitic or ferritic, should only be used within the limits of ASME B31.3 provided the installation is approved.  Usage in hydrocarbon or dangerous material services requires review and approval. Restrictions on the use of ductile iron, cast iron and low melting point material valves are necessary to prevent their failure in the event of a fire.  Such a failure would either feed the fire or interrupt flow of a required utility, unnecessarily increasing the hazardous condition.
  2. Cast iron valves may only be used in water service not subject to freezing. Restrictions on the use of ductile iron, cast iron and low melting point material valves are necessary to prevent their failure in the event of a fire.  Such a failure would either feed the fire or interrupt flow of a required utility, unnecessarily increasing the hazardous condition.
  3. Aluminum and copper based alloy valves (e.g., brass or bronze) which experience significant loss of mechanical properties at elevated temperatures should not be used in the following services:
    • Services in which failure of the valve in a fire would increase the hazardous condition (Examples: Prevent steam flow to any process pump, steam header, or emergency steam line.)
    • In hydrocarbon service