China has developed its own subsea pipeline inspection device, ending foreign companies' dominance in this field, said the machine's designers.

"We are the first in China to successfully develop this kind of device, for which our offshore oil industry had waited more than 20 years. Now we can proudly announce that China can inspect its subsea pipelines on its own," said Zhou Ming, director of the Beijing Huahang Radio Measurement Institute that developed the equipment.

Such a device uses magnetic flux leakage method to detect corrosion and pitting in pipelines and is used to inspect about 70 percent of existing pipelines in the world.

Previously, China depended on overseas manufacturers for this kind of equipment, resulting in high expenditure and risks like exposing sensitive information to foreigners, he said.

The device developed by the institute passed a host of stringent tests in pipelines in the Bohai Bay in October, proving it is ready for mass production and formal operations, said Zhou.

"We are now working with China National Offshore Oil Corp to promote the machine as well as our inspection service in the oil and gas industry," he said.

"Compared with foreign companies, our charges will be much lower and our product is as competitive as theirs."

The Zhou-led institute specializes in radar and photoelectric equipment for spacecraft and rockets. Though its focus is still on space equipment, many of its researchers have been designated to take advantage of their expertise in the space industry to develop products to serve other business sectors.

The value of the institute's civilian businesses reached nearly 400 million yuan ($62 million) last year. The institute plans to double the figure by 2020.

CNOOC owns hundreds of subsea pipelines off China's coastline that spans more than 6,000 kilometers, the company's statistics show.

A standard industry practice is to check a pipeline every three to five years to make sure it is working well with no damage or risk like corrosion.

Industry observers said for long, several foreign firms, including General Electric and ROSEN Group, have dominated the pipeline inspection services segment in the Chinese market. They charge an average of $10,000 for each km of pipeline they check.

"They make millions of dollars from the Chinese market. They don't sell the machine to Chinese oil companies, but only provide the Chinese clients an inspection report," said Zheng Li, chief designer of the equipment at the institute.

"Our machine is capable of continuously inspecting about 100 km in a single mission. Moreover, we not only provide inspection service but offer a solutions package," she said.