I. Core Structure and Compensation Principle

• Axial compensation: Achieved through bellows expansion (2-6mm per corrugation) to offset thermal expansion/contraction;
• Lateral/angular compensation: Hinge structure allows ±15° angular displacement, guided by rods to control direction;
• Typical structure: Composed of bellows (304 stainless steel), hinge assembly (Q345B carbon steel), and limit devices, suitable for 3D displacement compensation in coal ash pipelines (axial ±80mm + lateral ±50mm).

• Bellows inner wall surfacing with Stellite alloy (HRC55-62), wear rate <0.05mm/year at coal ash flow velocity ≤25m/s;
• Flow deflector sleeve with ceramic patches (Al₂O₃ ≥95%), abrasion resistance lifespan increased 3x at impact angles <30°.

II. Technical Parameters and Coal Ash Working Condition Adaptability

III. Installation Key Points for Coal Ash Pipelines (Anti-clogging/Wear)

1. Flow direction and angle control

• Coal ash medium must flow from the large end of the compensator deflector sleeve to avoid particle deposition;
• Installation angle ≤15° from horizontal, vertical pipelines require anti-ash accumulation baffles (spacing ≤1.5D).

2. Support system design

• Fixed support bearing capacity ≥1.2×medium thrust + compensator reaction force (e.g., DN300 pipeline thrust 50kN, support needs to bear 60kN);
• Guide support spacing ≤4D, clearance ≤3mm to prevent bellows eccentric wear.

3. Anti-clogging and ash cleaning devices

• DN50 drain port at compensator bottom, purged every 8 hours (compressed air pressure 0.4-0.6MPa);
• Vibrator installed 3D downstream of elbows (frequency 20-30Hz) to prevent ash accumulation.

IV. Failure Prevention Solutions for Coal Ash Working Conditions

V. Industry Application Cases

• Coal ash conveying pipeline in a power plant:
  • Conditions: DN400, temperature 180℃, coal ash particle size ≤50μm, flow velocity 22m/s
  • Solution: Install 3 sets of 3D compensators (30m spacing) with ceramic-lined flow deflectors
  • Effect: 3 years of leak-free operation, bellows wear <0.1mm, ash cleaning frequency reduced by 50%
• Coal chemical pulverized coal gas pipeline:
  • Conditions: DN600, temperature 450℃, dust concentration 80g/m³
  • Customization: 310S stainless steel bellows + water-cooled jacket, compensation axial ±120mm + lateral ±80mm
  • Cost: 25% lower than traditional compensator solutions, maintenance cycle extended to 18 months

VI. Selection Calculation Steps

1. Three-dimensional displacement calculation
   • Axial displacement: ΔL=α×L×ΔT (α=12×10⁻⁶/℃, L=pipeline length, ΔT=temperature difference)
   • Lateral displacement: Determined by pipeline layout (e.g., L-bend lateral displacement=0.002×L)
   • Example: DN500 pipeline (L=50m, ΔT=200℃) has 120mm axial displacement, paired with 60mm lateral compensation 3D compensator.
2. Wear coefficient correction
   • When coal ash particle size >20μm, compensator life needs to multiply by correction factor K=0.6-0.8 (smaller K for larger particles).

VII. Maintenance Specifications

• Daily inspection: Observe compensator displacement marks daily, check supports if deviation >10% of rated value;
• Quarterly maintenance: Clean seal housing dust, inject high-temperature lubricating grease (drop point ≥350℃);
• Annual testing: Ultrasonic thickness measurement (replace if wall thickness thinning >15%), air pressure test (0.8MPa for 30min).