All fire protection lines within buildings shall be installed in such manner that all pipes will be easily accessible for inspection at any time. Underground pipes outside of buildings must be placed and maintained at a minimum depth of four and one-half feet. No connections with a fire protection system will be permitted to supply water service for commercial or industrial use, unless the connection has been approved by the customer’s fire underwriter and unless the commercial or industrial use is metered.
(Prior Code, § 51.81)  Penalty, see § 53.999