Flange form selection
Thread Content
Can flammable media use flat welding flange with neck? The "Chemical Pipeline Design Manual" stipulates that necked butt welding flanges should be used for general flammable, explosive, moderately hazardous (toxic) media. However, there is no such requirement in standards such as GB50316. It only states that pipes under frequent and large temperature cycles and pipes under violent circulation conditions should not use flat welding flanges. So, can flammable media use necked flat welding flanges?
GBT 20801 has requirements
The new version of 20801 only states that pipelines with flammable and toxic media must not use plate flat welding flanges. There are no specific instructions for stiffened flat weld flanges.