3 The butterfly plate adopts the structure without pin, connectivity and sealing are reliable.
3 The butterfly plate adopts the structure without pin, connectivity and sealing are reliable.
蝶板采用无销结构，连接及密封可靠。
3 The butterfly plate adopts the structure without pin, connectivity and sealing are reliable.
蝶板采用无销结构，连接及密封可靠。