N.Y. Comp. Codes R. & Regs. tit. 12, § 4-1.10
After March 31, 1965 the installation of a nonstandard component as part of a boiler is prohibited unless the component is by its nature incapable of causing the boiler to be defective or unless after such inspection and tests as he may deem necessary a certified boiler inspector shall find the component safe for the use intended.