📘 Introduction

In an ERW tube mill, the accumulator ensures continuous strip feeding during coil changes, keeping the mill running without stoppage. The most common types are Horizontal Spiral, Vertical Spiral, Cage (Loop Cage), and Disc Accumulators. Each design fits different production speeds, strip sizes, and factory layouts.

1. Horizontal Spiral Accumulator

• Structure: Strip forms a horizontal spiral on a circular track; a movable trolley adjusts coil diameter.

• Storage Capacity: 150–400 m

• Line Speed: 120–180 m/min

• Best For: Medium-speed ERW lines, structural and mechanical tubing

2. Vertical Spiral Accumulator

• Structure: Strip forms vertical spiral layers; height is utilized to increase storage capacity.

• Storage Capacity: 300–600 m

• Line Speed: 150–250 m/min

• Best For: Medium-to-high-speed lines, wide strip, medium-to-large tubes

3. Cage Loop Accumulator

• Structure: Strip passes through rotating cages to create large vertical loops with precise tension control.

• Storage Capacity: 300–700+ m

• Line Speed: 180–300+ m/min

• Best For: High-speed lines, API pipe, automotive tube, continuous production

4. Disc Type Spiral Accumulator

• Structure: Strip is wound into a flat spiral on a rotating disc for compact storage.

• Storage Capacity: 80–250 m

• Line Speed: 80–150 m/min

• Best For: Small OD, thin-wall tubes, compact workshops

Detailed Performance Comparison

1. Strip Handling & Tension Control

2. Line Speed Capability

• Disc: 80–150 m/min

• Horizontal Spiral: 120–180 m/min

• Vertical Spiral: 150–250 m/min

• Cage Loop: 180–300+ m/min

Conclusion: For welding speeds >250 m/min, Cage Loop is the only reliable choice.

3. Storage Capacity & Buffer Efficiency

4. Floor Space & Height Requirements

Key Notes:

• Low building height → Horizontal / Disc

• Limited floor space → Vertical / Cage

5. Engineering Reliability

• ⚙️Disc: Simple, limited application

• ⚙️Horizontal Spiral: Stable, low maintenance

• ⚙️Vertical Spiral: More complex, better performance

• ⚙️Cage Loop: Maximum continuous stability, suitable for 24/7 operation

Professional Selection Guide

➡️Step 1: Define Target Welding Speed

• ≤150 m/min → Disc / Horizontal

• 150–250 m/min → Vertical Spiral

• ≥250 m/min → Cage Loop

➡️Step 2: Evaluate Strip Specifications

• Thin strip ≤1.2 mm → Disc / Horizontal

• Wide strip >500 mm or thick >3 mm → Vertical / Cage

• High-strength steel → Cage Loop

➡️Step 3: Consider Pipe Size

• Small OD ≤60 mm → Disc

• Small-medium OD ≤89 mm → Horizontal Spiral

• Medium-large OD ≤168 mm → Vertical Spiral

• Large or API OD ≥219 mm → Cage Loop

➡️Step 4: Analyze Workshop Layout

• Low building → Horizontal / Disc

• Narrow building → Vertical / Cage

• No pit foundation → Disc / Horizontal

➡️Step 5: Balance Budget vs Performance

• Economical → Disc Type

• High cost-performance → Horizontal Spiral

• High-speed stability → Vertical Spiral

• Continuous high-end production → Cage Loop