Solid PU pipe coating are merely applied for the protection of the interior surface of pipe lines transporting water or an abrasive media. PU foam pipe coating on the exterior of pipelines are added for thermal insulation purposes. Bauhuis has supplied several pipe coating plants for the application of both types of coatings. For the application of the foam on the exterior Bauhuis can offer various solutions like a continuous system involving a helical pipe conveyor or discontinuous system with a pipe coating buggy. In the later case the pipe is put with the outer ends on travelling pipe rotation unit and passes a stationary positioned spray gun. PU pipe coating plants are provided with all necessarily PU pipe coating equipment including a tank farm, temperature controlled day tanks, dosing equipment for adding blowing agent and a main mix pump with spray guns all provided by renowned suppliers.
- Pipe sizes between Ø4 and Ø60 inch
- Pipe length 20 to 80 Ft (8 to 24,5 meter)
- Thicknesses up to 200 mm
- Jacket by side extrusion
PU pipe coating (Polyurethane pipe coating) in the shape of solid or foam type are applied more and more nowadays. Solid PU pipe coatings are applied to the inner- or outer surface a pipe as an alternative for 3-layer (external pipe coating) or liquid epoxy (internal pipe coating) for higher abrasive applications. The PU Foam pipe coatings are applied to external surface of the pipe to reduce heat loss and to prevent hydrate formation in on-shore and subsea gas pipelines. The PU Foam pipe coating helps to maintain fluid viscosity due to the superior insulation properties and low thermal conductivity. PU foam pipe coatings are in most cases applied on top of a previous corrosion coated (FBE pipe coating or liquid epoxy) pipe.
Solid PU coating equipment
The PU pipe coating (polyurethanes pipe coating) is either sprayed onto the pipe surface with the pipe ends placed on rotation units or onto the pipe travelling passed the airless spray gun on a helical pipe conveyor. The last type of application requires a very fast curing PU as before the pipe hits the first conveyor wheel after application the pipe coating must be able to carry the weight of the pipe.
PU Foam coating equipment
For the application of PU foam coating Bauhuis offers various PU Foam pipe coating equipment like tilting tables whereby the pipe is first inserted into a jacket with spacers present between the jacket and the steel pipe. Then the pipe is placed on a tilting table and foam is injected from the top in between the jacket and the pipe.
Another method of installing the jacket, is to have first the foam sprayed onto the pipe on pipe rotation units or helical pipe conveyor and then wrap a film of PE coming out of an extruder around the foamed pipe while travelling on a helical pipe conveyor.
In case the pipe line specifications requires this, stations for installing heat tracing or leak detection wires into the PU Foam pipe coatings can be added to the PU Foam pipe coating equipment.