Skip to main content

Contact UsContact Us

Service Overview

In recent years, trouble reports about SF6 gas leakage from GIS and oil leakage from oil-immersed transformers have been increasing. Judging from Electric Technology Research Association's Electrical Cooperative Research report(Vol. 61 No. 3 , 2005), the cause of gas / oil leakage is mainly the corrosion of the flanges of GIS / Transformer tank. Under those circumstance, Hitachi Power Solutions offers the exterior repairment services to prevent those serious leakages.


As a manufacturer, we offer consistent service, from preliminary surveys to inspection, with knowledge and skills that are familiar with the products.

To maintain the quality of T&D facilities, a high level of product knowledge is required in addition to precision painting and repair technology knowhow. Having maintained and repaired many T&D facilities, we possess abundant product knowledge and expertise and skill in construction. Exterior repairment often requires detailed work which can lead directly to electrical outages or major accidents. Please consider relying on Hitachi Power Solutions, a manufacturer familiar with the construction and features of equipment.

Equipment Check
Work Plan Design
On-site Work
We intricately check the condition of equipment, identity parts where rust, corrosion, and other deterioration is occurring, and check the progress of the deterioration. We discuss work details based on the results of the equipment check and survey, and offer the details to the customer. Our specialists carry out the work following the agreed upon plan. Once completed, we check to ensure the work was completed according to the plan and verify conditions before delivery.

We offer leaked oil prevention that does not require equipment to be shut down or taken apart.

We use Seam Coat*, a coating film that prevents oil leakage from oil cooling pipes, various oil conduits, valves, flanges, and more in transformers without replacing gaskets and so on.

Seam Coat is a coating film that prevents oil leakage, developed by Midas Safety Co., Ltd.

[Commentary picture]1 Before repairment

[Commentary picture]2 After repairment with Seam Coat

Application Areas

The entire substation

Transformers, gas insulated switchgears, power distribution panels, and more.


Water-proofing Flanges on a Gas Insulated Switchgear (Caulking)

When rainwater and other moisture gets in through the flange joints of gas insulated switchgears, internal rusting progresses and this can lead to gas leakage. Defects have also been reported where the water retained inside can freeze, adding excess stress to insulation spacers and causing cracks to occur. We caulk flanges with the appropriate procedures to prevent these kinds of defects.

[Commentary picture]1 Remove rust and deteriorated caulking, clean, and degrease

[Commentary picture]2 Recaulk

[Commentary picture]3 Paint refinishing

Repairment of Corroded Parts of Wire Ducts

Some repairment can not be done easily, as severing the control wiring laid inside wire ducts can have a major impact on equipment operations. We can make these repairment without severing the control wires, according to the construction of the wire duct and the state of rust and corrosion.

Example of repairment of corroded part of duct

[Commentary picture]1 Cut the duct

[Commentary picture]2 Weld the parts of the duct together

[Commentary picture]3 After repairment

Part Replacement

We replace parts in a location where replacement is simple. We take great care when replacing parts to prevent from damaging control wiring and piping.

Example of duct part replacement

[Commentary picture]1 Repairment part of duct corroded by rust

[Commentary picture]2 Duct repairment complete

[Commentary picture]3 Replacement of covers to those with ventilation openings

Repairment of Snow Protection Roof

Snow protection roof for GIS

Removal of corroded roof frame

Frame restored through welding, repairment, and recaulking

Work Carried Out through Installation of All-weather Scaffolding

We can erect roofed scaffolding and work to minimize the effects of weather on work quality and schedule.

Base Repairment

Old concrete can chip or peel easily on corners. After removing the damaged parts, we repair with mortar supported by an arrangement of bars as necessary.

Damage to aging base

Support from reinforcing steel

Frame is set up and
concrete is poured

Base with completed repairment