Document OQjvQJmV8m9q4R2ROL4eVEv

410 CHAPTER 16 1957 Guide are considered consistent with good practice, although there are boilers which have high efficiencies and also operate at higher transmission rates. RATING AND TESTING CODES' Heating boilers are. usually rated according to codes developed by the Steel Boiler Institute, the Institute of Boiler and Radiator Manufacturers, the American Gas Association, and the Heating, Piping and Air Condition"ing Contractors National Association, whose test codes have been prepared specifically for the purpose of obtaining information required for estab lishing acceptable ratings. In view of the preference of industry for the above codes which have been found suitable for determining efficiency and performance characteristics of boilers, the following Society codes have been withdrawn. ASHVE Standard and Short Form Heat Balance Codes for Testing Low-Pressure Steam Heating Solid Fuel Boilers--Codes 1 and 2--(Revi sion of June, 1929).1 ASHVE Performance Test Code for Steam Heating Solid Fuel Boilers-- Code No. a--(Edition of 1929).* The ASHVE Standard Code for Testing Steam Heating Boilers Burning Oil Fuel, (Adopted June; 1938).' The ASHVE Standard Code for Testing Stoker-Fired Steam Heating Boilers, (Adopted June 1938 ;4 also adopted by the Stoker Manufacturers Association, 1938). The various current rating and testing codes will be discussed in follow ing paragraphs in which limitations, methods of application, and resulting ratings will be described. The Steel Boiler Institute has adopted a rating code for boilers designated Table 1 Steel Boilers and Table 2 Steel Boilers and a testing code for Oilfired Table 2 Steel Boilers (SBI Rating Code, Sixth Edition, July 1954). Tables 1 and 2 of this chapter show the, SBI ratings of these two classes of boilers. The Table 1 boilers (defined as those having 129 to 3571 sq ft of heating surface and formerly designated as Commercial boilers) are rated in square feet E.D.R. (steam) on the basis of heating surface with limitations set for grate area, furnace volume, and furnace height. The Table 2 boilers (defined as those having not more than 294 sq ft of heating surface and formerly designated as Residential boilers) are rated from tests of oil-fired boilers, with limitations in relation to heating surface and testing conditions. Stoker-fired and gas-fired Table 2 boilers are rated (SBI Net Rating) not in excess of the oil-fired rating. Hand-fired Table 2 boilers are rated (SBI Net Rating) not greater than fourteen times the heating surface. The Institute of Boiler and Radiator Manufacturers has adopted a code for rating cast-iron heating boilers, based upon performance obtained under controlled test conditions. This code applies to all sectional castiron heating boiler except those of magazine-feed type. The Gross I = B = R Output is obtained by test, and is subject to cer tain limiting factors. For hand-fired boilers, the number of boilers of 8 series to be tested, the minimum overall efficiency, the minimum time limit (the time an Available Fuel Charge will last when burned at a raw which will produce the Gross I = B=R Output)', the chimney area 88 height, and the draft in the stack are all subject to the limits established in the code. Tests are run using anthracite coal of standard specification^ Bituminous coal and coke ratings are the same as for anthracite. For automatically-fired boilers, the number of boilers of a series to be . ^ Heating Boilers, Furnaces, Space ;Heaters 411