Damper valve; DN 3600 & 1800

Siv cov khoom siv muaj zog, ua cov khoom siv ntau lawm kom tau raws li koj cov kev xav tau, cov kws tshaj lij kev lag luam thiab kev lag luam tawm txawv teb chaws thiab cov kev pabcuam kom txaus siab, tht valve!