Luck Lake Irrigation District Transformer Re-Gasket

SECTOR: 
Agriculture

CLIENT: 

Lucky Lake Irrigation District

DURATION OF PROJECT:

6 Days

PROJECT SUMMARY:

The 72 kV: 4.16 kV transformer at the Luck Lake Irrigation District (LLID) Pumphouse has developed several moderate leaks over its service life. The transformer was manufactured in 1988, and since that time no refurbishment or leak repairs had been undertaken. Several gasketed and sealed components developed leaks causing a minor loss of oil (found 300 liters below nominal) and potential environmental concerns to the surrounding area and waterbody. The unit is filled with mineral oil and has been confirmed to have 0 ppm PCB content. Dynamo was retained to repair leaking components and perform oil processing on the unit.

Over a six (6) day period, the unit was drained and repairs were made to all leaking components, including: bushing gaskets, hatch gaskets, piping and Victaulic fittings, valve stems, valve packing, valve seats, and flange gaskets.

A 50-ton mobile crane was used to remove bushings and radiators. A 30,000-liter stainless steel tanker was used to store oil for the duration of work and positive pressure maintained with a mobile dry-air compressor (dew-point -70°C).

A total of thirty-six (36) gasket seals were replaced, with twenty-three (23) valve seats, seals, and piping repairs made.

After all the gasket work, the transformer was evacuated to 0.31 mmHg of vacuum and vacuum filled. The unit was topped-up and fully tested prior to re-energization. Oil was processed to approximately five (5) total passes, 120,000 liters of total processing volume.