... /16949 certified) ball valve bushing DX boundary lubrication bushing is based on a composite material with 3 firmly bonded layers:steel as backing ... interlayer and modified POM as lining layer. It fits well for low speed, heavy duty and normal temperature and saves cost ... bushing, trunnion bush, steering joints bushing, copper bushes and so on.HISTORY:nearly 20 years,CERTIFICATE:In the year 2010, we ...