400 phone:400-004-3339

Airtight:13841387818 Service Hotline:15842354234

Fushun CRES Instrument Co., Ltd.

Fushun CRES Instrument Co., Ltd.


Tel : 024-58198005/024-58198006

M/T : 13841387818/15842354234     
Fax : 024-58198007
E-mial : 

Add :  "CRES Instrument", Building 9, Taiwei Automobile City, Gaoshan Road, Shuncheng District, Fushun City, Liaoning Province

©2021 Fushun CRES Instrument Co., Ltd.    辽ICP备08103263号    Powered by 300.cn ShenYang


Sampling method of power oil (series products)

Sampling method of power oil (series products)

Technical Support
Release time:

This method is suitable for the collection of oil filled electrical equipment such as transformer, transformer, oil switch, casing and the oil analysis test sample of steam turbine.

1、 Sampling tools

1. Sampling bottle:

500 ~ 1000ml glass bottle with stopper and label.

Scope of application

It is suitable for routine analysis.

Preparation of sampling bottle

The sampling bottle is washed with detergent, then washed with tap water, then washed with distilled water, dried and cooled, and then the bottle plug shall be closed.

2. Syringe:

20-100ml full glass syringe (copper head is good) shall be used. The syringe shall be installed in a special oil sample box, which shall be light proof, shock proof, moisture proof, etc. The syringe head is sealed with a small rubber head.

Scope of application

It is suitable for the determination of water content in oil and analysis of dissolved gas (total gas content in oil).

3. preparation of syringe

Before using the sampling syringe, clean it with organic solvent, tap water and distilled water in sequence, dry it fully at 105 ℃ or dry with blower hot air. After drying, cover the head with small rubber head for use (to be kept in the dryer).

4. sampling pipe for oil barrel sampling

5. sampling spoon for oil tank or tanker

Sampling from oil filled electrical equipment shall also be provided with sealed sampling valve (or oil drain joint) to prevent pollution, reliable medical metal three-way valve and transparent rubber pipe (oil resistant) or plastic pipe as oil guide pipe.

2、 Sampling method and sampling location

1. sampling in oil drum:

The oil test shall be taken from the bottom of the polluted base, and the upper oil sample can be sampled if necessary.

Before opening the barrel cover, clean grade a cotton yarn or cloth shall be used to wipe the outer part of the barrel cover, and then take the sample with clean and dry sampling pipe. When sampling from the whole batch of oil drums, the number of barrels sampled shall be sufficient to represent the quality of the batch of oil.

Several single oil samples shall be taken according to the above table for each test, and then they shall be mixed into a mixed oil sample evenly.

2. sampling in tank or tank car:

The oil sample shall be taken out from the bottom of the tank with serious pollution, and the upper oil sample can be spot checked if necessary.

3. sampling in electrical equipment:

For transformers, oil switches or other oil filled electrical equipment, samples shall be taken from the lower valve. Before sampling, the oil valve shall be cleaned with clean grade a cotton yarn or cloth, and then the oil shall be drained and washed clean.

For the casing to be sampled, sampling shall be conducted from the sampling hole during power outage maintenance.

If there is no oil filling electrical equipment without oil drain pipe or sampling valve, try to take samples during power failure or maintenance. The imported equipment with full seal and no sampling valve shall be sampled according to the regulations of the manufacturer.

Sampling in oil system of steam turbine (or turbine, regulating camera, large steam driven feed pump):

The normal supervision test is sampled by the oil cooler.

When checking the oil dirt and water, take samples from the bottom of the tank.

Note: ① the safety regulations of oil equipment shall be strictly followed during sampling.

② In addition to the test of one part of the oil samples of infrastructure or imported equipment, the other part shall keep the appropriate time for examination.

③ For items with special requirements, sampling shall be conducted according to the requirements of test method.

3、 Analysis and sampling of water and dissolved gas in transformer oil

Sampling method:

1. requirements for sampling

a. The oil sample shall represent the oil of the equipment body, and sampling at the dead angle where the oil circulation is not sufficient shall be avoided. Generally, sampling valve at the bottom of equipment shall be used for sampling, and in special case, sampling can be conducted at different sampling positions.

b. Sampling requires full sealing, that is, the sampling connection mode is reliable, and the dissolved water and gas in the oil cannot escape, and the air cannot be mixed (the remaining air in the sampling joint must be drained). No bubbles shall be generated in the oil during operation.

c. Sampling shall be carried out on sunny days. After sampling, the syringe core is required to move freely to avoid negative pressure cavity.

d. Oil samples shall be kept away from light.

2. sampling operation

a. Remove the dust cover at the oil drain valve of the equipment, and loosen screw 6 to let the oil flow out slowly.

b. Install oil drain joint 4 on oil drain valve, and place oil drain hose (oil resistance) on the upper part of oil drain joint, and remove air in the joint until oil flows out.

c. After connecting the conduit, tee and syringe in sequence, install it at 5 places of oil drain joint, remove the dead oil of oil drain valve according to the direction of arrow, and flush the connecting pipe.

d. Rotate the tee, and use the pressure of the oil to inject the oil into the syringe, so as to wet and flush the syringe (the syringe shall be washed for 2-3 times).

e. The rotating tee is isolated from the equipment body and the syringe core is pushed to empty.

f. The rotating tee is isolated from the atmosphere, and the natural pressure of the equipment oil makes the oil enter the syringe slowly.

g. When the oil sample in the syringe reaches the required ml, immediately rotate the tee to isolate it from the body, pull the tee off the syringe, and after the air bubble in the small rubber head is replaced by oil, cover it on the head of the syringe, place the syringe in the special oil sample box and fill in the sample label.

3. sampling quantity:

a. The oil samples used for the determination of water content in oil can be used for analysis of dissolved gases in oil at the same time, and it is not necessary to take samples separately.

b. The conventional analysis shall take samples according to the oil quantity of the equipment, so as to meet the test requirements.

c. When the dissolved gas analysis is carried out, the sampling amount is 50-100ml.

d. The oil sample specially used for determining the water content in oil can be 20ml.

4. sample label:

The contents of the label include: unit, equipment name, model, sampling date, sampling location, sampling weather, temperature of sampling oil, operation load, oil grade and oil quantity.

4、 Transportation and preservation of oil samples

The oil samples shall be analyzed as soon as possible, and the oil samples for dissolved gas analysis in the oil shall not exceed four days; The oil sample with water content in the oil shall not exceed ten days. During transportation, oil samples shall be protected from severe vibration, container breakage and air transportation as much as possible. During the transportation and storage of oil samples, it is necessary to avoid light and ensure that the syringe core can slide freely.