Has a gauge glass and overflow pipe to a drain. Closed-type — welded gas tight and located above boiler. Tank is partially filled with water, leaving an air cushion for expansion. • Make sure this type of tank is fitted with a tank fitting, such as the B & G Tank-Trol or Taco...
Something as simple as the following will catch any overflow. The one tile vertical gap between airflow tiles is there to force any beads to start dripping. This way you don't get a bead of crude oil swapping the order of all the materials in the materials ...