In an assembly for cylindrical drill pipes made for the transport of different kinds of fluids, a combined flange assembly can combine the functions and can be assembled under low time consumption and at low cost. Drill rods are connected by axially directed bolts inserted in the outer wall of a first...http://www.google.es/patents/US6527064?utm_source=gb-gplus-sharePatente US6527064 - Assembly for drill pipes
