Insulating Oil Purifiers

SESCO manufactures three different families of Insulating Oil Purifiers. The SES320 series  "condition" or prepare new and group II in service dielectric fluids for high voltage transformer use by removing dissolved water, dissolved gas, and particulate. The SES320R can "Regenerate" badly degraded group III in service fluids. The SES320R adds an additional adsorbent treatment stage  (fullers earth) to extend the SES320  process to restore oil TAN, IFT, color, and dissipation factor values. The SES441 series of substation maintenance trailers are available for less demanding applications that require only filtration. The SES441  package can also include dry air and vacuum dry out systems.      

Oil Processor Upgrades

SESCO can upgrade your aging oil processor. Upgrades can range in scope greatly. Most are typically minor. There are many factors involved but even major upgrades salvaging only functional major components make economic sense under the right circumstances. 

Lube Oil Purifiers

SESCO designs and manufactures high-efficiency vacuum dehydration systems for industrial lubricants used in high water contamination environments.  The SES300 purifiers are high-efficiency vacuum distillation systems.  Compared to the typical "mass transfer" vacuum dehydrator the SES300 will remove 5X-10X  the amount of water contamination per pass. Water contamination from seal failure can force costly outages and lost production. Properly sized, the SES300 can be used to offset significant water ingression problems, allowing the repairs to take place during scheduled maintenance outages. Equipment payback can be immediate.

Vacuum Systems

The SES420 family of vacuum packages are targeted at transformer dry out applications but can be custom engineered for other industrial applications on request. The SES420 series is packaged in four standard size ranges ( 375,700,1200,1650 CFM) with backing vacuum pump type, booster bypass, and VFD atmospheric startup options. The systems are available as stand-alone skids, stand-alone cargo trailer packages, and SES320 oil processor integrated.  

Dry Air Systems

The SES329 family of dry air and dry breathing air systems are targeted at transformer service applications but can be custom engineered for other industrial applications on request. The SES329 series is available as either dry air or dry breathing air quality configurations at two dewpoint quality standards (-56°C & - 65°C).  Multiple compressor options facilitate stand-alone and SES320 oil processor integrated package configurations. Dewpoint and CO monitoring instrumentation is optional but recommended.

Fullers Earth Systems

The SES522 Adsorbent Treatment Systems (Fullers Earth) remove polar contaminants such as acids, oxidation by-products, and color bodies from numerous fluids. The bulk media  systems can be used for stand-alone treatment or in conjunction with the SES320 conditioning system to regenerate badly degraded ISO class III insulating fluids and with multiple passes, "desludge" badly contaminated transformers. The SES522 systems are available in three tower sizes as well as in dual and single tower configurations.

Oil Booster Pumps

SESCO SES330 series inlet oil booster pumps are low pressure, low suction head, portable booster pumps designed to assist oil processors when circulating oil through a partially filled transformer being held under full vacuum. The SES330 is available in centrifugal and positive displacement pump versions. 

Vacuum Line Cold Traps

SESCO manufactures vacuum line cold traps to help quantify the rate and volume of water extraction during the transformer vacuum dry out process. The water vapor separates as ice when it contacts the trap cold collector surface. An extraction rate is determined by measuring the collected ice (water) over a given time period. The trapped ice must be thawed to measure the water collected. Refrigerated and liquid nitrogen cooled traps are available. Single stage refrigerated traps are used for trapping between vacuum pump stages. Liquid nitrogen and two stage (Cascade) refrigerated systems are cold enough to trap at evacuation pressures.

Transformer Vacuum Manifolds

The SES425 manifolds are designed for use on transformers with Qualitrol pressure relief valves. Evacuation and  Evacuation with hot oil spray versions are available. With an all aluminum construction, the SES425 series are easy to handle and maneuver into position on site. If Qualitrol pressure reliefs are not used the SES425 series will be custom designed to your specifications.

Oil Booster Heating Systems

The SES460-2400  booster oil heating system is a versatile oil heating tool designed to aid oil processing in cold weather transformer installation and maintenance.  The SES460-2400 can be set up to boost oil processor return or supply temperatures. It also can be being used as a stand-alone 40 GPM heating circulation system for preheating transformers and storage tanks in cold conditions. The variable speed positive displacement pumping system tops out at 40 GPM.  Three individually controlled 32 kW low watt density heating banks provide 96 kW of heating capacity.  When supplied by an oil processor (or pump) a pump bypass circuit is provided to allow the system to be used as a push through heating system.  A  weather-protected NEMA 4X control panel is provided.


SESCO offers a wide variety of state of the art instrumentation. Ask about standalone and integrated upgrade options

Stock Equipment

Stock equipment completed or in production.