Relieve Overpressure Protection Costs Consider simple but effective alternatives to relief valves

摘要

THE ENGINEERING firm hired to tackle the process hazard assessment project list was convinced that our methanol/water tower required a relief valve.I wasn't-because an unimpeded vent line ran from the shell of the condenser to its receiver and then to the thermal oxidizer inlet drum.So,we checked the fire case flow against the choked flow for this vent pipe.Sure enough,the vent line had been sized for sufficient flow to continuously vent the column and the condenser.Some might argue a relief valve could provide cost savings by preventing the loss of methanol.However,keeping records and doing maintenance on equipment incurs costs.A vent line is a one-and-done solution.