// CODE SNIPPET
603.8 Underground Ducts
JUMP TO FULL CODE CHAPTER
Plastic ducts shall be constructed of PVC having a minimum pipe stiffness of 8 psi (55 kPa) at 5-percent deflection when tested in accordance with ASTM D2412. Plastic duct fittings shall be constructed of either PVC or high-density polyethylene. Plastic duct and fittings shall be utilized in underground installations only. The maximum design temperature for systems utilizing plastic duct and fittings shall be 150°F (66°C).
Related Code Sections
603.8 Duct Systems, Underground Ducts
Ducts shall be approved for underground installation. Metallic ducts not having an approved protective coating shall be completely encased ...
Mechanical Code 2018 of Maryland > 6 Duct Systems > 603 Duct Construction and Installation > 603.8 Underground Ducts
506.3.10 Exhaust Systems, Underground Grease Duct Installation
Underground grease duct installations shall comply with all of the following: Underground grease ducts shall be constructed of steel having ...
Mechanical Code 2018 of Maryland > 5 Exhaust Systems > 506 Commercial Kitchen Hood Ventilation System Ducts and Exhaust Equipment > 506.3 Ducts Serving Type I Hoods > 506.3.10 Underground Grease Duct Installation
188.8.131.52.5 Public Emergency Alarm Reporting Systems,
Raceways or ducts entering buildings from underground duct systems shall be effectively sealed with an identified sealing compound or other means ...
National Fire Alarm and Signaling Code 2016 of Maryland > 27 Public Emergency Alarm Reporting Systems > 27.7 Public Cable Plant > 27.7.1 Requirements for Metallic and Fiber-Optic Systems — Metallic and Fiber-Optic Interconnections > 184.108.40.206 Underground Cables > 220.127.116.11.5