●CP System — PL-06″ SGPC–TIPU
impressed current · 16.4 km · 16 test postsAsset & CP scheme
| Structure | PL-06″ SGPC–TIPU |
| Length | 16.4 km |
| Diameter / wall | 168.3 mm × 7.11 mm |
| Installed | 2011 |
| Design code | ASME B31.8 |
| Coating | 3-layer polyethylene (3LPE) |
| Product | Sales gas, 48 barg |
| Soil | Sandy loam, 2,400–9,600 Ω·cm |
| CP scheme | Impressed current (ICCP) |
| Rectifiers | TR-01, TR-04 |
| Groundbed | GB-01 deep well, 46% consumed |
| Test posts | 16 (TP-0101 to TP-0116) |
| Criterion | −850 mV instant-OFF vs Cu/CuSO₄ |
| Survey interval | Annual (≤ 15 months) |
Protection by segment
1 of 5 segments unprotected| Segment | Instant-OFF | Against criterion | State |
|---|---|---|---|
| KP 0.0 – 4.0 | -1042 mV | Protected | |
| KP 4.0 – 8.0 | -968 mV | Protected | |
| KP 8.0 – 10.0 | -894 mV | Protected | |
| KP 10.0 – 14.0 | -698 mV | Unprotected | |
| KP 14.0 – 16.4 | -988 mV | Protected |
KP 10.0–14.0 fails on a single severe coating holiday at KP 12.4 (DC-2201, 34% IR). The rest of the line meets criterion comfortably, which is why the fix is a local excavation rather than a CP redesign.