When extremely tight shutoff is required, globe and check valves may be supplied with Kel-F, Teflon or other soft inserts.是什么意思_When extremely tight shutoff is required, globe and check valves may be supplied with Kel-F, Teflon or other soft inserts.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句