Blue Sky,as a professional marine machinery manufacturer,established in 1989 and focus on valves,air vent head,fittings etc more than 25 years in Qingdao,China.Our mainly products were globe valve,angle valve,gate valve,SDNR valve,check valve,hose valve,storm valve,butterfly valve,air vent head,strainer tec, according to DIN,JIS,ANSI,API,BS,GB,CB,CBM,AS standard. Material is including cast iron,ductile iron,cast steel,cast bronze,forged brass,stainless steel,forge steel,and can be extensively used in marine, petroleum,chemical, metallurgical,electric power,architectural,agriculture field.We are here to provide you with safe and reliable goods.Quality was always our main priority,our quality control program make sure that no defect or poor workmanship will be supplied.In these years we had got ISO Certificate,Design Certificate,Works certificate,Foundry certificate,Type Approval certificate,API 6D from marine classification society&industrial field.So we can provide more faster and conveniently certificate service for customer requirement, such as ABS,BV,NK,KR,CCS,DNV,LR,GL,RINA Certificate etc.