API SPEC 12B:2008 pdf download.Specification for Bolted Tanks for Storage of Production Liquids.
API 2000. The pressure setting should be from to I oz)ln.2 less than the opening pressure of devices used for emergency venting. Annex B is provided as a guide to aid in the selection of venting devices, where required,
5.2 Emergency Venting
When storage tanks containing flammable liquids are exposed to fire, the venting rate may be in excess of that resulting from a combination of normal thermal effects and oil movement, Unless tanks are installed in remote locations, the purchaser shall provide, or cause to be provided, pressure relieving devices which will provide capacity in addition to normal venting to meet the requirements tabulated in Table Cl. The opening pressure of such devices shall not exceed the design pressure of the tank on which they are installed The maximum internal pressure under relieving conditions should not exceed that tabulated in Column 6 of Table C.l. Pressure relieving devices may take the from of larger or additional vent valves, Larger or additional thief hatches or deck dome covers (see FIgure 5) installed with loose fitting long bolts and suitable gasket so that the dome cover will lift at the required pressure.
NOTE With &ainage as used In Table C.1, Colunvi 5 means that flammable or combustIe liquids ll not be retained near the tar* by dykes or firewals.
6 Erection and Clean Up
Tank staves shall be erected with the male side on the left when facing the outside surface of the stave (see Figure 4).
NOTE The dimensions as specified herein are based on the assumption that most of the slack, due to the difference ii bolt and bolt-hole diameters. will be taken up in all stave joints by shppage when the tank is .iitiy filed. The bottom and deck bolt-orcie diameters provide for such slippage. At the time of erection, some pirwiing of the vertical stave joints w b€ required to bilig the bolt holes into ali,ment.
Upon completion of erection, the erector shall remove or dispose of all rubbish and other unsightly material caused by erecting operations and shall leave the premises in as good condition, as found.
7 Marking
Tanks manufactured in conformance with this specification shall be identified by a nameplate bearing, as a mWlmum, the information shown in Figure 12.