 SEATTLE, April 28, 2021 PRNewswire -- ClearSign Technologies Corporation Nasdaq: CLIR ClearSign or the Company, an emerging leader in industrial combustion and sensing technologies that improve energy, operational efficiency and safety while dramatically reducing emissions, announced today that the Company has received official certification from the Chinese government confirming that its 125hp 2-ton fire tube boiler burner is approved to be sold in the Chinese market. With this certification, the Company can produce, market and sell its 125hp fire tube boiler burners throughout China. 