Tool design and construction for leak testing of gas electrofusion polyethylene coupler by internal injection system

Rasooly, Meysam; Technical Inspection; Iran

Homagerani, E.M.; Isfahan Province Gas Company; Iran
Alavi, M.; Isfahan Province Gas Company; Iran
Rasooly, M.; Isfahan University of Technology; Iran

ID: ECNDT-0401-2018
Download: PDF
Session: Oil & Gas 5
Room: H2
Date: 2018-06-12
Time: 14:10 - 14:30

Nowadays, in many gas projects polyethylene pipes are great replacement for steel pipes due to the ease of implantation. However, applicable and economical nondestructive tests for control the electofusion welding processes in polyethylene pipes is one of the essential aspect to consider. In this paper, we introduce an efficient equipment for test of electrofusion polyethylene coupler in the implementation condition of gas network projects to detect the leakage by internal pressure method. Results of laboratory experiment on artificial defect samples and site work procedure are described and computer simulation by finite element and CFD software are also shown.
The history of high density polyethylene pipes (HDPE) utilization came back to 1950 in American gas industry. In this regards, inspection, maintenance and repair of these pipes are vital for constructors. Preparation of technical inspection processes to prevent risk and cost of environmental pollution and gas waste due to gas leakage are the first and chief aspects of such reconstruction. To have an integrated gas network, the inspection is required during pipes production, fitting, installation level and even after gas injection in operation stage. These examinations have significant roles in the safety and proper function of gas distribution systems. Meantime destructive tests due to their characteristics and damaging nature are not affordable and could not be used for all couplers in gas pipe connections. Regarding to effect of instrument efficiency on the integrity of electrofusion welds, nondestructive test that could be perform on all electrofusion couplers is required. Using ultrasonic and thermography methods in the previous studies which conducted to assess electrofusion welds were acceptable in preliminary results on laboratory scale. However, because of the high equipment cost, operator skill requirements and the non- applicability of these tests, using these methods have been stopped in gas projects.