In the manufacturing process of electric heating tubes, powder filling and tube reducing are the two core steps that determine product insulation and thermal efficiency. This article provides a detailed interpretation of the Standard Operating Procedures (SOP) for these two processes.

Electric Heating Tube Powder Filling Machine: The Art of Precision Filling

Core Principles:
The powder filling process core lies in the filling density of magnesium oxide (MgO) powder and the accurate positioning of the center rod.

Parameterized Control:
The operator must enter the parameter mode via the touchscreen to precisely set:
– Fill speed: Controls powder flow rate
– Delayed oscillation frequency: Ensures uniform distribution
– Tube length: Adjusts for different sizes

By 2026, mainstream equipment has achieved microsecond-level response, ensuring uniform powder distribution.

Automated Process:
In automatic mode, the system guides the placement of empty tubes using indicator lights. The critical step is the wire hanging stage:
1. Heating wire must be accurately hung on the hook
2. After being pulled into the tube
3. Terminal pin and lower plug tightness must be checked

Fault Interception:
If any deviation occurs in the length of the guide tube or mandrel:
– Emergency stop must be triggered
– Origin reset required
– Prevents heating wire breakage
– Prevents incomplete filling

Tube Reducing Machine: The Key Pressure for Thermal Efficiency

Purpose:
Tube reducing is not only about reducing the tube diameter, but more importantly, about achieving a dense state of the internal magnesium oxide powder.

First-Piece Inspection System:
Before starting the tube reducing machine:
1. Check hydraulic block pressure
2. After processing the first piece
3. Conduct first-piece self-inspection:
– Tube diameter dimensions
– Surface smoothness
4. Mass production can only proceed after passing inspection

Lubrication and Die Maintenance:
During operation:
– Apply appropriate amount of lubricating oil
– Reduce frictional heat
– Minimize surface scratches

If scratches are found on tube wall:
1. Machine must be stopped immediately
2. Die must be polished or repaired
3. Ensure product appearance meets export standards

SOP Summary

Powder Filling Steps:
1. Verify tube and wire specifications
2. Set machine parameters
3. Perform system calibration
4. Load empty tubes
5. Start automated filling
6. Monitor process continuously
7. Inspect completed tubes
8. Document batch information

Tube Reducing Steps:
1. Verify tube specifications
2. Check hydraulic system
3. Set reduction parameters
4. Install die
5. Process first piece
6. Inspect first piece
7. Start production run
8. Perform periodic checks
9. Document production data

Quality Control Points

Powder Filling:
– Fill density consistency
– Wire centering
– Absence of voids
– Proper termination

Tube Reducing:
– Final diameter tolerance
– Surface finish
– Concentricity
– No cracks or defects

Standardized operations in powder filling and tube reducing are essential for producing high-quality electric heating tubes. Following these SOPs ensures consistent product quality, efficient production, and reduced defect rates.