The return water connections to all low-pressure, steam heating boilers supplying a gravity return heating system shall be arranged to form a loop so that the water cannot be forced out of the boiler below the safe water level. This connection, known as a "return pipe loop connection," is shown in the current edition of the ASME Code, Section IV.
16 Va. Admin. Code § 25-50-300
Statutory Authority: § 40.1-51.6 of the Code of Virginia.