During the process of crossover and parallel alternate current transmission lines with the underground pipeline, induced voltage and currents may emerge because of the influence of induction which can influence an operating process of the mentioned pipeline. These factors may, in their turn, result in intensive electrolyte corrosion. Alternate Current-Drainage Systems (ACDS.SK) of the main pipelines are designed for the process of protection of the main pipelines through the process of alternate current-drainage induced by transmission lines into the ground conductor securing protective potential of the construction at the same time.
ALTERNATE CURRENT-DRAINAGE SYSTEMS OF THE MAIN PIPELINES
ACDS.SK ТU 3435-004-09890805-2013
- Alternate Current-Drainage of the current induced high voltage transmission line into the ground conductor.
- Protective potential in the ground conductor leakage prevention
- Operating characteristics of the unit:
- Current-drainage indication (current resolution – 100 мА);
- Power terminal clips voltage indication (current resolution – 100 mV).
- Lighting protector unit
- Set up amperometric transformer
- Fast electronic protection from emergency operations mode.
- An ability to integrate into the Smart Integrated Corrosion Monitoring System (SICMS)“Atlantic”.
ACDS.SK are included “The Core Products Register” of PJSC “Transneft”. They meet the requirements of OTR -75.180.00-TRR-035-15 with changes 1 to “Appendix I” of the BR 29.240.00-TRR-163-16 “Service Electric Power Transmission Lines and Cathode Protection Units. Maintenance Rules and Regulations” as well as the BR 91.020.00-TRR-170-17 “The Main Pipelines Transportation of Oil an Oil Products.Cathode Protection System of the Objects of the Main Pipeline.Design Rules and Regulations”.
An Alternate Current-Drainage System ACDS.SK consists of the following general elements:
- MOC Column (P02 type);
- Current-Drainage Block – CDB.SK;
- lighting protector unit;
- composite ground conductor with a cable for setting up.
|Nominal current-drainage 50 Hz, А||20||40||80|
|Minimum value of current-drainage to put an indication system into operation, А||2||2,5||3|
|Accessible voltage of direct current, Umax, V||12|
|Current flow under Umax = 12 V, not more than, mА||1|
|Total short-limited current-drainage 1 sek/50Hz, IA[~], А||400|
|Operating temperatures rate, °С||-60 ÷ +60|
|Cables cross-station, not less than, mm2||35|
|An item set up inside the MOC (P02 type without a composite ground conductor) mass, kg||22 ± 1,5|
General characteristics of combined ground conductor of the standard kit
|Ground conductor type||Name||Frames||Ground conductor material||Ground conductor with support connections mass, kg|
|Horizontal||h||Line 4×40×2000 мм*||Stainless steel (S) или
hot dip galvanizing steel (HD) или copper steel(C)
|2,65 ± 0,1|
|Vertical||v||Bit insert Ø16×1500 mm*||2,5 ± 0,1|
* – possible replacement of standard frames according to the Customer’s Request.