What are the classifications of coating methods for large-diameter water delivery plastic-coated steel pipes

the coating methods of plastic-coated steel pipes for large-diameter water delivery are divided into two categories: internal coating and external coating at the same time, and internal coating and external coating separately.

process coating methods are also divided into two categories: first internal coating, then external coating; first external coating, then internal coating.

there are five types of internal coating methods: well coating, non-static gun extension rod spraying, non-static powder pump push-pull rod spraying, powder deduction, and vacuum suction coating.

there are four types of external coating methods: well coating, electrostatic spraying, fluidized bed dipping, and waterfall coating.

there are mainly two types of internal and external coatings at the same time: well coating (internal coating and external coating) and fluidized bed dip coating (external dip coating, internal non-static powder pump push-pull rod spraying).