Valve producer engineers plans for expansion overseas, reports Cai Xiao in Xinchang, Zhejiang.

'We don't rest on our laurels. If we don't constantly innovate and reinvent ourselves, we'll become obsolete," said Zhang Yabo, chief executive officer of Zhejiang Sanhua Co Ltd, the world's largest air conditioner valve producer.

Based in Xinchang, Zhejiang province, Sanhua has a huge share of the global valve market: more than 50 percent for four-way reversing valves (which allow air conditioners to switch between cooling and heating modes) and more than 30 percent for service valves (which connect the indoor and outdoor units of split-type air conditioners).