... in sidewall way.ZSTDY-68 degree also known as concealing type sprinkler with a round cover outside which can help to ... two different nominal diameter, that is,DN 15mm, connect thread R1/2”, flow coefficient 80, rated W.P 1.2MpaDN 20mm, connect ... thread R3/4”, flow coefficient 115, rated W.P 1.2 Mpa automatic sprinkler