Contact Us

Vertical external oil
Your current location: Home >> Product >


Vertical external oil metal corrugate conservator for transformer adopts the advanced super flexible stainless steel bellows that is the volume compensation element and the isolation seal element. The volume compensation for transformer insulation oil is realized. The stainless steel bellows is an air sac that communicates with the atmosphere, and placed in insulating oil. The lower part of the conservator is connected to the transformer body through the connecting pipe. When the insulation oil expands or contracts with the change of temperature, the bellows is pushed up and down, thus changing the volume of the oil cavity in the conservator to realize the volume change compensate of the insulating oil. The bellows adopts the vertical working method, is the most reasonable, the most reliable, no additional stress ideal structure.


Wide range for applicable type—The common compensation volume range of the conservator is from 100~15000kg, which is suitable for various types of oil-immersed  transformers and other power equipments with total oil weight of transformer not more than 160t.

Perfect structure—The vertical structure is adopted, and the bellows is stretched up and down, without additional stress, and no guiding device. The bellows is used as air bag, more reliable and safer.

High compensation abilityThe conservator adopts single core, has compact structure, small invalid space and large compensation capacity.

Long service life—The compensation component is stainless steel, without aging, the product life can reach 30 years, and has the same lifetime with transformer.

Maintenance-free—The products adopt the non-condensing structure design, the stainless steel bellows is completely immersed in the insulating oil as the breathing chamber, the inner surface is the heat dissipation surface, no condensation, no need to adopt the hygroscopic device, so the product realizes maintenance-free.

Strong pressure resistanceThe negative pressure capacity of the bellows is -0.1Mpa, which fully meets the requirement of full vacuum filling. The positive pressure capacity of the bellows is 50KPa, which meets the requirements of transformer tank test.

Super flexible—The bellows adopts supper flexible design, and the maximum opposite force of the bellows is less than 0.006MPa, which does not affect the normal setting of the transformer protection device.

Leakage protection—As the air bag, the bellows has the secondary protective effect on the leakage of the insulating oil, which has little risk and has no direct effect on the operation of the transformer.

Oil level gauge—The external magnetic coupling retroflex oil level gauge is used to completely isolate the oil storage cavity, which is convenient for inspection and replacement. It is safe, reliable and accurate.

Oil level remote transmission—It is easy to realize the remote transmission of oil level signal, and can be configured with multi-function oil level signal remote device according to the user's requirement, which can realize remote computer monitoring.


1.Model selection

①Provide transformer total oil weight, min and max environment temperature for transformer use area.

②Refer to the following figure to give the relative size of transformer connection, specify special requirements, such as switch cabinet, vacuum oil filling, oil level remote transmission, oil level gauge rain cover, etc.

③The manufacturer shall cooperate to select the model of conservator, and finally determine the product structure size.

2.Selection methods

①According to the total oil weight of the transformer, check the last column of the table, and select the optimal conservator size (width and length) suitable for transformer space in the model that meets the requirements of many types.

②Calculate the minimum rated compensation of the conservator according to the total oil weight and maximum temperature difference of the transformer.

③Then, the minimum rated compensation for the design requirements is indicated in the conservator model △, which is the confirmation of the model.

Example: 240MVA/220KV transformer, the total oil weight is 50t, and the compensation amount of conservator is more than 4500dm3.

The model of the conservator is: BP3L1260x4900-4500, which is calculated by the manufacturer and the height of the conservator is 1370mm.

3. Product series parameter list

Note: This table is a regular series. The conservator of outside the table scope can be designed according to customers' requirements. Please contact our technical department.


1. Preparation before installation

Release pressure: Open the breath vent, exhaust vent and oil injection vent, release the internal pressure of the conservator, and when opening the vale, it should be inhaled strongly.

2.Conservator installation

①The conservator is installed in the position, connected with the transformer pipeline, and fix conservator.

②Connect the oil injection pipe and exhaust pipe to the lower part of the transformer and connect the valve with reliable seal.

③Connect the control circuit of oil level alarm device.

④After installation, prepare oil injection.

3.Oil injection procedure

Inject insulating oil: Open the valve of the breath vent and exhaust vent, and fill the conservator with oil from the transformer body or the oil injection vent;

Exhaust:The oil level indicator is continuously raised after oil injection, and when the indicator is close to the value corresponding to the oil temperature (one calibration in advance), close the breath vent (with the plug). Continue to inject until the air in the conservator is discharged from the exhaust vent and the oil is stable outflow, then close the exhaust vent and stop the oil injection.

Adjust the oil level:Open the breath vent to check whether the oil level is corresponding to the oil temperature curve. If the oil level is high, the oil should be properly discharged from the oil injection vent. If it is low, the oil can be replenished properly. The operation does not need to open the exhaust vent, but need to open the breath vent and keep opening.


※When the oilinjection is finished, the working stateof the conservator is the breath vent is normally open, and the exhaustvent and oil injectionvent are sealed reliably.

※Vacuumoiling ofconservator (therequirements should be mentioned whenordering)

If the conservator needsvacuum oiling togetherwith transformer body, the exhaust vent must be connected to the vacuum system through "the transition jar",and the breath vent must keep opening when vacuuming,and meet the specification requirements of the pressure value (minimum 13Pa). Open the oil valves, insulating oil under vacuum statewill passinto thetransformer tank andconservator. When insulating oil isdischarged from exhaustvent into the transition jar,thenquickly shut down and sealexhaustvent, and continue toinjectoil through the oilinjection vent tomeetoil temperature corresponding to the oil level.