Nebraska Administrative Code
Topic - LABOR, DEPARTMENT OF
Title 229 - DEPARTMENT OF LABOR
Chapter 4 - GENERAL REQUIREMENTS FOR BOILERS AND PRESSURE VESSELS
Section 229-4-016 - Special requirements for hydronic (glycol) heating systems
Current through March 20, 2024
A. Systems where there is a possibility of contamination between the potable water system and the heating system shall be protected in accordance with state and local codes. Where there are no local codes, the International Plumbing and Mechanical Codes should be used as a reference for the protection of the potable water system.
B. All boilers supplying the heating system shall have safety controls to protect against a low water condition. The controls shall shut down the boiler and require a manual restart. The controls shall be installed and meet the requirements of ASME CSD-1, Part CW for the specific type of boiler.
C. A means shall be provided to refill the hydronic heating system. This means can either fill the system while in operation or require a shutdown prior to filling.
D. The discharge from the boiler safety relief valve and the boiler drains shall be piped to an atmospheric collection tank. The ends of the piping shall be visible to determine if a safety relief valve or drain valve is leaking past the seat. Certain types of glycol require a special permit for discharge to a city sewer system.
The requirement for an atmospheric collection tank may be waived provided the owner or installer provides documentation to the Chief Boiler Inspector that the municipality has approved the discharge of the glycol mixture to the sewer system. This documentation shall include the type of glycol to be used, its concentration in the system, and a signature and title of the approving authority.
E. Hydronic piping systems shall be designed and installed to permit the system to be drained. Where the system drains to the plumbing drainage system, the installation shall conform to the local codes. Where there are no local codes the International Plumbing and Mechanical Codes should be used as a reference.
F. The boiler shall have isolation valves on the inlet and outlet piping.
G. All boilers used in hydronic heating systems shall meet the requirements of ASME Section IV, Part HG, and shall be stamped with the ASME Certification Mark with the "H" Designator. Units with the ASME Certification Mark with the "HLW" Designator or items certified as meeting the requirements of ANSI Z 21.10.3 shall not be used in hydronic heating systems.
H. Records shall be maintained and available to the inspector that show the required glycol concentration, the results of all tests performed to ensure the concentration percentage is being maintained and the addition of glycol to the system.
