Where an air distribution valve manifold is used and its air sub-header shutoff valve is not accessible from the manifold, a shutoff valve at the manifold shall be provided.是什么意思_Where an air distribution valve manifold is used and its air sub-header shutoff valve is not accessible from the manifold, a shutoff valve at the manifold shall be provided.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句