MOLECULAR SEAL Molecular Seal, located below the flare tip reduces the purge or sweep flow by 70%. Internal can over can construction is more durable and reliable than the "maze" type of seal. The molecular seal's larger diameter increases wind loading of the flare stack, and may require structural changes to stack design. An inspection / clean out port is installed on the lower portion of the molecular seal for maintenance. An internal draining system is used which allows any condensation, rain, or other liquid, which becomes trapped, in the liquid seal to drain down the stack. This internal draining eliminates the need for periodic draining of the seal. A seal, which fills with liquid, can collapse the flare stack. Typical construction is carbon steel. top