Section 160.190  Piping – Emergency Internal Check Valves

In addition to any normal valves, there must be an extra valve at each pipe line connection to any tank below normal liquid level, (regardless of when installed) which valve is effective inside the tank shell and is operated both manually and by an effective heat actuated device which, in case of fire, will automatically close the valve to prevent the flow of liquid from the tank even though the pipe lines are broken from the tank. These extra valves are not required in crude oil tanks in oil fields, on tanks at refineries, or on tanks at terminals which are equipped with a swing line or where facilities are provided to transfer the contents of the tank to another tank in case of fire. On tanks installed prior to April 14, 1977, emergency check valves may be external, if the size of the opening is too small to admit the smallest emergency check valve provided:

a)         The valve used incorporates a shear section, and

b)         The valve is so installed that any undue strain beyond the valve will not cause failure between the valve and the tank.

c)         When an opening on a previously installed tank is enlarged, an internal valve is installed.

(Source:  Amended at 9 Ill. Reg. 10012, effective October 1, 1985)