That minimizes the possibility of ice plugs according to NFPA 13 page 103
Drawing labels, details, and other text information extracted from the CAD file (Translated from Spanish):
Heated area, Valv. Normally open control, Mt valve With hole in. On the clapper, Valve Of preaction sooa, Valve Main control, water supply, pressure regulator, Heated area, Air compressor tank, Freezer air inlet, retention valve, Two easily removable air lines, Refrigerated space, In., Air pressure source of water supply, Air supply, Two easily removable pipe sections, do not., date, Notes, Apr., Revisions, do not., date, Project name, Name of the plane, Measurements on site, Id project, drew by, scale, reviewed by, date, file name, do not. Plan, June, Vo. Bo., Indicated, owner, appendix, Nfpa page
