ScottPearson
Chemical
I have several solvent storage tanks stamped at U-Stamped at 40 psig/150 F with a Conservation Vent/Vacuum vent installed on the tank. A secondary emergency manway vent is also on the tank. Typical pressures do not exceed atmospheric/ambient conditions, however I need to consider a Fire Scenario and Pump Overpressure. Vapor Pressure of the solvents at normal Temps do not exceed the MAWP. There is also not Nitrogen or purge gas connected to the tanks. The reported capacities appear to be ok for these even at the low set pressures (4 oz vent -6 oz hatch) The problem I see is that these devices are not stamped with capacities or set pressure.
Do I need an additional Relief Valve/Rupture Disc etc to satisfy the code? Are the conservation vent and hatch all that are necessary or is an ASME certified relief device at a stamped capacity required? i.e. do all ASME Stamped vessels need Stamped/Certified Relief Devices on them even when they are typically run at conditions much less than what the MAWP is on the vessel? And, can these be set at pressure below 15 psig?
Do I need an additional Relief Valve/Rupture Disc etc to satisfy the code? Are the conservation vent and hatch all that are necessary or is an ASME certified relief device at a stamped capacity required? i.e. do all ASME Stamped vessels need Stamped/Certified Relief Devices on them even when they are typically run at conditions much less than what the MAWP is on the vessel? And, can these be set at pressure below 15 psig?
