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Subchapter 1. Unfired Pressure Vessel Safety Orders
Article 6. Anhydrous Ammonia

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§505. Installation of Mobile Storage Tanks.

(a) Mobile storage tanks shall meet the requirements of Section 504 except that:

(1) The design of saddles, bolsters, and/or other fastenings may be based on the empty weight of the tank for other than vertical loadings.

(2) In addition to the requirements of Section 504 (f), there shall be available a container of not less than 50 gallons of fresh water unless there is immediately available another safe, reliable, and accessible source of water.

(b) When containing NH(3) liquid, mobile storage tanks shall be located in accordance with Section 501(c).

(c) Mobile storage tanks shall be maintained substantially level and be securely blocked against accidental movement and shall be adequately supported independently of the wheels when containing NH(3) liquid.

(d) Only flexible connections shall be made to mobile storage tanks. No permanent piping to other installations is permitted. The loading and unloading connections shall be securely fastened to the vehicle frame or to the tank supports.

(e) All liquid shall be removed from mobile storage tanks before being moved to a new location.

(f) Unless surrounded by a rugged steel fence or equivalent, all liquid and vapor outlets shall be kept effectively locked when unattended.

(g) Transportation tanks shall not be used as mobile storage tanks without written permission from the Division, unless they are in full compliance with both Sections 504 and 505.


1. Amendment of subsection (b) filed 12-8-72 as procedural and organizational; effective upon filing (Register 72, No. 50).

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