BOILERS. Air Vent. Supply. Drain Valve

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1 BOILERS AND WATER HEATERS Boilers BOILERS Vent (Chimney) Return Pressure Releif Valve Aquastat Air Vent Pressure Reducing Valve Water Feed Valve Flow Control Valve Supply Pressure / Temp Gauge Expansion Tank Circulator(s) (pump) Gas Valve Burners Drain Valve YOU SHOULD KNOW: IMC 005., M00.3: All boilers must have a shutoff valve in the supply and return piping (multiple boilers each boiler shall have an individual shutoff valve in the supply and return piping). M00.: Electrical and mechanical operating and safety controls for boilers shall be listed and labeled. IMC 00., M00.: Must have a pressure gauge and a temperature gauge or combination thereof (must indicate temperature and pressure within the normal range of the system s operation). M00.3: Steam boilers shall have a water-gauge glass and a pressure gauge (IMC 00.). IMC 006.3, M00.4: Boilers must be equipped with pressure-relief valves with minimum rated capacities for the equipment served (must be set at the maximum rating of the boiler). M00.4: Discharge from pressure-relief valve must be piped to drains by gravity to within 8" of the floor or to an open receptor. M00.5: All steam and hot water boilers shall be protected with a low-water cutoff control (IMC 007.). 6

2 BOILERS AND WATER HEATERS Expansion Tank EXPANSION TANK No. Code Description M003. Hot water boilers must be provided with an expansion tank. M003. Non pressurized expansion expansion tanks shall be securely fastened to the structure or boiler and supported to carry twice the weight of the tank filled with water. System Volume Pressurized Diaphragm Type Non-pressurized Type Capacity is based on an average water temperature of 95 F, fill pressure of psig and a maximum operating pressure of 30 psig System (volume) includes volume of water in boiler, convectors and piping, not including the expansion tank YOU SHOULD KNOW: M003..: Pressurized expansion tanks shall be consistent with the volume and capacity of the system and shall be capable of withstanding a hydrostatic test pressure of.5 times the allowable working pressure of the system. 7

3 Confined and Unconfined Space CONFINED AND UNCONFINED SPACE Height of Room Length of Room Width of Room Section IFGC Combustion Air is the air necessary for complete combustion of a fuel. When a fuel gas appliance is placed, proper air flow is critical for the fire to burn properly. You must determine first if the area is Confined or Unconfined. Confined: A space that has a volume of less than 50 cubic feet per,000 British thermal units per hour of the aggregate input rating of all appliances installed in that space. Unconfined: A space that has a volume NOT less than 50 cubic feet per,000 British thermal units per hour of the aggregate input ratings of all appliances installed in that space. If appliances are to be installed in a confined space, there are three types of ventilation covered in the code: Direct, Horizontal, Vertical. Each has different requirements for net ventilation. (see page 38) Always begin by determining whether appliances will be placed in confined or unconfined space. Step Step Determine CF of space: L 3 W 3 H of room. Identify total BTU s of appliance(s) to be installed. Step 3 Divide total BTU s by 000. Step 4 Multiply the quotient from Step 3 by 50. Step 5 If the product of Step 4 is less than the CF determined from Step, the space is unconfined. If it is greater than the CF as determined from Step, the space is considered to be confined. Move to the next page to size your vent openings. 8

4 Vertical Ducts to Attic VERTICAL DUCTS TO ATTIC W 3 L 5 min. sq. in. per 4,000 Btu/h W L = Airflow No. IFGC IRC Description G G Two openings must be provided. One within one foot of the ceiling and one within one foot of the floor. Where directly communicating with the outdoors, each opening shall have a minimum free area of square inch per 4,000 Btu/h of total input rating of all appliances in the enclosure. Example: Calculate the net opening (in square inches) required for a 45,000 BTU appliance. Step The total BTU s is 45,000 Step 45,000 divided by 4, The net area of the openings required for each of the two vents is.5 square inches. Round Duct Equivalent of Net Square Inches Required 3" 4" 5" 6" 7" 8" 9" 0" " 4"

5 Crawl Space and Attic Venting CRAWL SPACE AND ATTIC VENTING W 3 L 5 min. sq. in. per 4,000 Btu/h W L = Airflow No. IFGC IRC Description G G Two openings must be provided. One within one foot of the ceiling and one within one foot of the floor. Where directly communicating with the outdoors, each opening shall have a minimum free area of square inch per 4,000 Btu/h of total input rating of all appliances in the enclosure. Example: Calculate the net opening (in square inches) required for a 45,000 BTU appliance. Step The total BTU s is 45,000 Step 45,000 divided by 4, The net area of the openings required for each of the two vents is.5 square inches. Round Duct Equivalent of Net Square Inches Required 3" 4" 5" 6" 7" 8" 9" 0" " 4"