SANRONG ball check valve is used by Carrier,York,DB,LG,Daikin now with or without spring SANRONG ball check valve is used by Carrier,York,DB,LG,Daikin now. SRG Steel Ball Single Direction Valve is ball style designed, the metals are sealed, the steel ball is directly flow designed, making the small diameter valve outlet large capacity, all the metal permits high temperature when in installation ...