"In the world only mama is dear. Child having mama is like a treasure."

This is a song most Chinese children sing as they grow up. When Zhang Hengzhen's daughter, 18, sang the song in her childhood, however, she changed mama into dad.

"When people interrupted and said she made mistakes, she would insist, 'No, dad is dear.'" recalled Zhang, a member of the 13th National Committee of Chinese People's Political Consultative Conference.

Zhang's daughter had her reasons. She had far fewer chances to see her mother - who often worked 12-hour night shifts as a technician for splitting decomposition - than to see her father, a teacher.

Splitting decomposition is a technique used to transform petroleum into ethylene. It needs complex procedures with the help of complicated facilities to make the transformation.

"The process is sophisticated. There are thousands of pipelines and thousands of valves with the combined facilities," said Zhang, 49, who works for the branch of China Petrochemical Corp in Maoming, Guangdong province.

Though Zhang is not in charge of all of the valves, she found herself enthusiastic about her job and devoted much of her spare time to researching about the whole process. When the facilities run smoothly, she focuses on instruction books that she often carries with her.

"I like the job and also think I am one that suits the post," she said.

It's not necessary to know all the valves to operate the facilities, but this will help a lot when malfunctions must be eliminated.

It took her about 10 years to learn the whereabouts and functions of all the valves.

Her devotion to the job, however, has brought her more in return than expected. Zhang has made numerous innovations to improve the facility's efficiency and created an operation method, now named in her honor, which has become famous industrywide.

Zhang now spends much of her day training young workers. She has found, however, that her young apprentices are not as passionate as workers of her age, partly because of blue-collar workers' low social status in the country.

This year, Zhang submitted one proposal to CPPCC National Committee, in which she suggested encouraging the "spirit of craftsmanship" and raising salaries for blue-collar technical workers.

"Technical workers play a key role as the country makes effort to transform its manufacturing industry to be intelligent," she said.

houliqiang@chinadaily.com.cn