BOLU manufactures Bi-metal Liners and Ceramic Zirconia Liners. BOLU also supplies genuine rubber and urethane liner seals. All our liner products are exchangeable with OEM products and meet or exceed API-7K standards. Bi-metal Liners High strength alloy steel outer hull High Chrome alloy inner sleeve honed to mirror finishes HP design to prevent inner sleeve slippage Exchangeable with OEM products Meet or exceed API-7K standards For more details, please feel free to tell us. Established in 1998, Botou Bolu Petroleum Machinery Factory is a professional manufacturer & supplier of mud pumps & parts. Bolu Petroleum can offer a full line of mud pumps & parts together with casing heads, drilling pipe join tools, TDB hydraulic profile control water plugging pump & parts , X-trees and many other oilfield drilling tools. Bolu Petroleum has been granted the API certification. Products are exported to America ,Middle East, etc. Bolu Petroleum is looking forward to being partners with you around the world.