PDFWAC 296-52-67140
Bulk storage bins.
(1) Construction. A bin, including supports, must be:
(a) Waterproof.
(b) Constructed of compatible materials.
(c) Adequately supported and braced to withstand the combined force of all loads, including impact from product movement within the bin and accidental vehicle contact with the support legs.
(2) Discharge gates. A bin discharge gate must be designed to lock and close tightly to prevent leakage of the stored product and to lock.
(3) Loading manways. Bin loading manways or access hatches must be hinged or attached to the bin and designed to lock.
(4) Electric conveyors. An electrically driven conveyor used for loading or unloading bins must:
(a) Comply with the requirements of WAC 296-800-280, Basic electrical rules.
(b) Be designed to minimize corrosion damage.
(5) Separation distances. The following separation distances must be followed:
(a) Blasting agent bins. Bins containing blasting agents must meet the distance requirements of:
(i) Table H-20, in reference to separation from inhabited buildings, passenger railroads, and public highways; or
(ii) Table H-22, in reference to separation from other explosives and blasting agent storage facilities.
(b) Ammonium nitrate bins. Bins containing ammonium nitrate must meet the distance requirements of Table H-22 in reference to separation of blasting agent and explosives storage.