These requirements apply to natural and propane gas-fired conversion burners designed and constructed primarily for the purpose of converting heating and process equipment form the use of other fuels to gas firing and/or firing new heating or process equipment. Section 2, Part "A" of these requirements apply to conversion burners having a maximum input rating within the range of over 400,000 BTUH, up to and including 10,000,000 BTUH. A conversion burner series extending below 400,000 BTUH input may be investigated according to the intent of these requirements. Section 2, part "B" of the standard includes requirements additional to those of Part "A" and apply to conversion burners having manufacturer's maximum input ratings in excess of 10,000,000 BTUH and up to and including 50,000,000 BTUH. Thee requirements apply to atmospheric, fan assist and forced draft type conversion burners. A conversion burner which complies with these requirements shall not be acceptable if it has features which impair the results contemplated by the requirements.