Both upstairs are translated according to German and American, only German is not American. Look it up in the dictionary. ...
I will do it.
Langfang is a place name. Just use pinyin Langfang.
Germany and America are Germans and Americans.
If it means beauty, it is a bit strange to translate it into English (because they are not named like this), so I suggest using Pinyin, Germany and America, because this is your company's own name.
Chemical industry: chemical engineering
Fire protection: fire resistance
Material: material
limited company
So together,
If it is a German-American joint venture: Langfang De&; American chemical engineering refractory co., ltd
If Demei is your own name: Langfang Demei Chemical Refractory Co., Ltd.
Fluent translation, pure American English, you can ask me any questions ~