In 1998, we started the design and manufacture of the mudline hanger series. In accordance with the clients' request, we have now worked out 5 types of mudline series, each of which has 5 different specifications. 
       And in 1992 we obtained the patent from the State Patent Bureau of P.R.of China for all these products. 
      Later, in order to further assure the quality of the products, we put the production line under the quality control of ISO9002 in 1997. 
      So far from design to production and to practical application, no quality complaint has ever occurred.