Buried gas pipeline corrosion problems

If all the re- excavation of pipeline corrosion, effort, and cost is enormous, only the implementation of the cathodic protection system is the most economical and easy solution , but because of pipeline construction without appropriate insulation measures and difficult to stop gas for insulation transformation, also difficult to obtain because there is no insulation and pipe -related parameters, so it can not be implemented before the relevant cathodic protection process calculation, which gives the cathodic protection system implementation has brought great difficulties. Cathodic protection methods are forced current law and the sacrificial anode protection laws, which force the current method due to the pipeline without insulation and building pipelines in multi- family area environment, technically feasible, it is difficult to use sacrificial anode cathodic protection law in the implementation of, since the anode at a certain distance pipelines laid in place, avoid other buildings and underground piping is protected against the impact of pipeline and technically feasible, so as to prevent the continuation of the development of corrosion, the use of sacrificial anode cathodic protection.

Soil environment in which the pipeline can not be changed, so we use the most simple way for family wings branch pipeline insulation insulation transform this transformation in the surge tank can be carried out at the flange, ie the surge tank flange screw plus insulating sleeve, the use of PTFE insulation pads, while the flange gasket without replacing the original asbestos mat, so stop making pipeline protection potential output has reached eleven, the realization will be, will be fully protected pipeline. To the factory area two parallel pipelines buried a short distance though, but after entering the factory overhead to each workshop, all of the overhead steel pipe support brackets, the number of overhead line length of about stents, each bracket is a ground point Meanwhile, the plant area electrolysis plant and other major electricity system grounding, causing stray current interference of the pipeline is also very obvious. This requires a large ground exclude exclude stray current interference impact of the pipeline. The best solution is in the pipeline overhead before installing insulation or insulating flange joints, were insulated transformation, then ground and stray interference issues have been resolved accordingly, but because of all gas production plant in the region, stop gas transformation will force production stopped, will lead to huge economic losses. Interference from stray current drain approaches can be taken to resolve the basic solution is buried pipeline overhead before installing zinc anodes with one hand, so that stray current through the zinc anode grounded to earth stray current row of people, partly because zinc anode has a more negative potential than steel, providing cathodic current can give pipeline, drainage and protection to achieve the dual purpose. But no matter what measures the exhaust stream draining grounding grounding resistance should be less than pipe body resistance, draining effect was obvious. However, due to high soil resistivity pipeline which should produce a ground resistance of less than pipe body resistance grounding is very difficult, but because the ground is used in zinc anode material is very expensive, can be installed to protect the pipeline, also Shangqie I do not know. In order to avoid blindness and unnecessary economic losses, we do not make any insulation transformation cases, an analog current cathodic protection test. To determine the case of non-insulated pipeline in the end require much cathode current cathodic protection system which re- determine the best solution embodiment.