... TRUST 2,all types to choose 3,professional production drainage cap 1.Ø20X13 wintersweet type,including long,middle and short ... tower type water draining cap3.piece material type water draining cap specification:250kg-DN15 500kg-DN23,DN25 1000kg-DN32 properities:high ... widely used for rough filtration and fine filtration of water treatment of oil and gas well,water well, sand control, chemical industry ...