Research And Development On The Hot Tap Machine For Large-diameter Oil And Gas Pipelines

Pipeline transportation is an important means of oil and gas transport, the high demand socialproduction and living for oil and gas promots the rapid development of the pipeline construction,making it one of the five modes of transportation. The trend of the pipeline construction is largerdiameter, higher pressure and the network coverage, The Φ1016mm and Φ1219mm steel pipeline isused widely with the12MPa delivery pressure. In order to protect the oil and gas supply security,reducing economic losses caused by the shutdown due to pipe failure,currently pipeline maintenanceand repair use non-stop tapping methods with pressure, pipe tapping machine is important equipmentduring the construction process. This paper proposes a new tapping machine design: a machine withpressure balance system for hot tapping on the large-diameter pipeline with high-pressure oil and gas.First this paper analysis the construction process of the hot tapping to determine the functionalitythat tapping machine required. On this basis, design the pipe cutter that is required to be able to tap ahole on the API5L grade X80pipe with maximum diameter up to60inches. Based on the principlesof metal cutting,we select AISI M48steel for cutter tip material. design a reasonable tool body, bladegeometry, and analyse the welding process between the knife blade and the body, a induction brazingmethod named "three-body one cream" is taked for the connection btween tips and body.Secondly,start the detail design including drive mechanism, power system,control mechanism andcounter for feed displacement, pressure balance. Drive mechanism is made of three hollow shafts,with screw rod and pin to pass motion and power, the system uses two hydraulic motors for power byhydraulic valve manual control.The pressure balance systerm is designed to reduce the pressure forceexerted to the boaring bar. Based on virtual prototype technology, creating three-dimensional modelsof the tapping machine by Solidworks, and making the virtual assembly and gap inspection.Kinematics and dynamics analysis by use of Simulation are Carried out, checks the reliability ofmovement design and structural design.At last studies the deep-hole machining technology,study the deep hole processing system such asGun drill systerm,BTA systerm,Double feeder systerm and ejector drill systerm, Hole axis deviationin the process were discussed and a preliminary solution is proposed.