An enclosure that looks simple is actually the product of five tightly controlled processes. Understanding the journey from flat sheet to finished box helps OEMs specify better, negotiate more effectively and spot quality problems early. Here is how we build heat pump enclosures at Fulei Metal.
Step 1: Laser Cutting
Every panel starts as flat sheet — typically SGCC/SECC galvanized steel at 1.2–1.5 mm. Our TRUMPF and domestic fiber lasers cut profiles, louvers, fan openings and mounting holes in one pass, holding ±0.1 mm. Cutting strategy matters: correct piercing order and gas settings prevent edge burr and heat-affected discoloration on galvanized coating.
Step 2: CNC Press Braking
Panels are folded on CNC press brakes with precision-ground tooling. Bend allowance and springback are calculated per material grade and thickness so that after folding, the box fits together within ±0.5° on angles and ±0.2 mm on critical dimensions. Consistent bending is what makes the four corners of an enclosure close cleanly.
Step 3: Welding
Corner seams are joined with spot welding (fast, strong, minimal distortion) or TIG welding where a continuous sealed seam is required for IP protection. Fixtures hold the assembly square while welding, and welders are qualified to the project’s standard.
Step 4: Surface Treatment
Depending on specification, panels go through degreasing, zinc plating, and powder coating at 60–100 µm. For galvanized base material, a duplex system (galvanize + powder) gives the longest outdoor life. We verify film thickness and adhesion on every production batch.
Step 5: Assembly and Inspection
Final assembly fits doors, hinges, gaskets, fasteners and drainage parts. Every unit is checked against the drawing: dimensions, squareness, weld quality, coating condition and IP sealing details. A dimensional report accompanies each batch.
Lead Times
Prototype enclosures typically ship in 10–15 working days after drawing approval; production orders of 100–500 units run 25–35 days depending on surface treatment load. RFQ files: STEP + 2D PDF. We reply with a DFM review within 48 hours.