Overpressure and underpressure protection during stripping or gas-freeing operations-B/ALL.

§ 39.6003 Overpressure and underpressure protection during stripping or gas-freeing operations—B/ALL. (a) The volumetric flow rates during stripping or gas-freeing operations must be limited within a range such that the cargo tank venting system required by 46 CFR 32.55 will keep the cargo tank within its maximum design working pressure or the maximum design vacuum. (b) Each barge must be fitted with a means for connecting the pressure-sensing and pressure-indicating devices required by 33 CFR 154.2203(g) and (o) on each cargo tank top, or on the common vapor header provided that pressures measured by the devices are adjusted to compensate for the pressure drop across the vapor piping from the cargo tank to the devices. The valve for the connection point must be labeled “Pressure Sensor/indicator Connection.” (c) For stripping operations with closed cargo tanks, the maximum stripping rate must not exceed the volumetric flow capacity of the vacuum relief valve protecting the cargo tank.