Every boiler or modular boiler shall have a shutoff valve in the supply and return piping. For multiple boiler or multiple modular boiler installations, each boiler or modular boiler shall have individual shutoff valves in the supply and return piping.
The minimum capacity of expansion tanks shall be determined from Table M2003.2.
EXPANSION TANK MINIMUM CAPACITYaFOR FORCED HOT-WATER SYSTEMS
|SYSTEM VOLUMEb (gallons)||PRESSURIZED DIAPHRAGM TYPE||NONPRESSURIZED TYPE|
For SI: 1 gallon = 3.785 L, 1 pound per square inch gauge = 6.895 kPa, °C = [(°F)-32]/1.8.
Pool and spa heaters shall be installed in accordance with the manufacturer's installation instructions. Oil-fired pool heaters shall comply with UL 726. Electric pool and spa heaters shall comply with UL 1261. Pool and spa heat pump water heaters shall comply with UL 1995 or CSA C22.2 No. 236.
Exception:Portable residential spas and portable residential exercise spas shall comply with UL 1563 or CSA C22.2 No. 218.1.