CATHODE PROTECTION SYSTEM FOR MAIN PIPE-LINES AGAINST CORROSION Russian patent published in 2001 - IPC

FIELD: protection of pipe-lines. SUBSTANCE: cathode protection system presents unit-box made of high- and low-voltage compartments. High- voltage compartment has high-voltage disconnector of power line with blocked grounding knife, dry power transformer, high-voltage cutouts, valve dischargers to protect against lightning overvoltage and bushing insulators. This compartment has mechanical interlocking between high-voltage disconnector of power line and entrance door. Valve dischargers against lightning overvoltage are equipped with set of overvoltage limiters, activation counters and indicators. Low-voltage compartment is fed from dry power transformer and houses source of guaranteed power supply with step-down transformer, heating panel with automatic disconnection, hour counter controlled by input automatic unit of switching gear, meter of protective polarization potential on pipe-line, set of telemetry aids connected to monitoring and controlling unit- boxes mounted on gate valves. High-voltage compartment is fitted with automatic valve that releases air pressure in case of short-circuit with subsequent ignition and is provided with warning light equipment mounted on cover of unit-box. Meter of protective polarization potential on pipe-line comes in the form of current interrupter and high- resistance voltmeter. Low-voltage compartment also houses cathode protection station with cathode and anode outputs, cathode protection equipment and low-voltage switching gears. Current interrupter is fitted with manual and remote controls. Set of telemetry aids incorporates system of telecontrol, telewarning, overvoltage protection, automatic valve activation, telecontrol over protective potential of pipe-line, telemeasurement of output protective potential, of output current and voltage of low- voltage compartment, communication lines. EFFECT: improved operational qualities and enhanced functional reliability. 11 cl, 5 dwg