Graco Inc.

Automatic internal & external coating with XM70

Italian Industrial Agency (IIA), based in Salgareda, Treviso, Italy, is a company that specializes in the production of hydraulic equipment, specifically designed for handling water for aqueducts, irrigation plants, etc.

IIA opened a production site in Tunisia and a new facility in Honduras to support the activities related to the Panama channel and the development of South America. Three years ago, they implemented the production of large diameter pipes (400-600 mm in diameter, 600-12200 mm in length, >20 mm thick). The new plant now offers automatic welding, automatic air sandblasting and automatic internal and external coatings. The main challenge for IIA was to find a good balance between cost effectiveness and productivity.

Fully automated system

The local Graco distributor, Verve, offered the Graco XM70 sprayer with two 83 liter XM tanks. The automatic loading of the tanks is handled by a president 10:1 pump. Base coat and catalyst are heated by two Viscon HP heaters and paired to 20 m long water-heated hoses, which then split into two automatic mixing blocks. Each mixing block is connected to an automatic airless spray gun which alternately paint the inside and the outside of the pipes.

The selection of the internal/external coating happens right after the proportioning valves where a G6000HR flow meter is installed for the base coat. The signal of the flow meter is processed by a Siemens PLC with custom software which also handles temperatures, pressures, flushing and alarms. All data is easily downloaded.

Since a fully automated system was installed, one of the main challenges was combining all information to guarantee the consistency of the coating and keep it in a closed loop based on the parameters set by the operator. To do so, the PLC controls and IP transducer regulates the pneumatic pressure to the motors of the XM’s volumetric pumps. The system is also equipped with remote assistance.

Consistent thickness

The results and the standards required by IIA were fully met and satisfying. A 2000 mm x 12200 mm pipe is fully coated (inside and out) in 30 minutes, including pauses to change spray guns. The customer was truly amazed by the consistency in thickness (500 microns), considering the abrasive nature of the fillings.