Plural-component spray equipment is the backbone of polyurea pipeline coating application. These sophisticated machines — operating at high pressure, elevated temperature, and with chemically reactive materials — require disciplined preventive maintenance to deliver consistent application quality and avoid costly downtime on the job site.
Daily Maintenance Procedures
At the start of each day, technicians should verify that heated hose temperatures are stable and uniform, check all fluid seals and O-rings for signs of wear or material buildup, verify that mix ratio is correct using graduated containers, and test spray pattern on a test panel before beginning production work. Any deviation in mix ratio exceeding ±2% should trigger equipment shutdown and investigation.
Isocyanate Crystallization Prevention
The isocyanate (A) component of polyurea systems will crystallize in cold conditions or upon moisture exposure, blocking filters, screens, and pump components. All equipment should be purged with clean solvent at end-of-day and stored with dry nitrogen blanketing on the A-side reservoir to prevent moisture ingress. A strict temperature minimum of 65°F for equipment storage prevents crystallization during cold weather operations.
Preventive Maintenance Schedule
A comprehensive PM schedule for plural-component spray equipment should include weekly inspection of heated hose elements and thermocouples, monthly replacement of pump packing and check valves, quarterly calibration verification of mix ratio sensors, and annual pump refurbishment by the equipment manufacturer’s certified service center.
Our Equipment Maintenance Library contains manufacturer-specific PM checklists for all major plural-component spray systems. Register for our equipment maintenance workshop to get hands-on training from certified equipment technicians.