Cage Loop vs Horizontal Spiral Accumulator: How to Choose the Right Accumulator for Your ERW Tube Mill

In an ERW tube mill, an accumulator—also known as a loop system—is a key machine that stores steel strip temporarily to ensure continuous production.

During tube production, coils must be joined together. However, the welding process requires the mill to stop briefly. Without an accumulator, the entire line would have to stop, reducing efficiency.

👉 This is where the accumulator comes in:

• It stores strip material in advance
• Releases strip continuously during coil change
• Keeps the tube mill running without interruption

Where Is the Accumulator Located in the Tube Mill Line?

The accumulator is typically installed between the slitting/uncoiling section and the forming section.

Typical Position in Production Line:

Uncoiler → Shear & Welder → Accumulator (Loop System) → Forming → Welding → Sizing → Cutting

👉 In simple terms:
It acts as a “buffer zone” before the forming mill.

Types of Accumulators: Cage Loop vs Horizontal Spiral Accumulator

There are two commonly used accumulator types in tube mills:

1. Cage Loop (Vertical Accumulator)⭐

What it is:
A cage loop accumulator stores strip in a vertical cage-like structure.

Key Features:

• Strip moves up and down inside a cage
• Compact footprint
• Suitable for medium speeds

Advantages:
✔ Space-saving design
✔ Lower initial investment
✔ Simple structure, easy maintenance

Disadvantages:
✘ Limited storage capacity
✘ Not ideal for very high-speed mills
✘ Strip stability can be slightly lower at high speeds

2. Horizontal Spiral Accumulator💡

What it is:
This type stores strip in a horizontal spiral (coil-like) form.

Key Features:

• Large strip storage capacity
• Smooth strip flow
• Designed for high-speed production

Advantages:
✔ Large storage capacity
✔ Ideal for high-speed ERW tube mills
✔ Better strip stability and less tension fluctuation

Disadvantages:
✘ Requires more floor space
✘ Higher investment cost
✘ More complex structure

Cage Loop vs Horizontal Spiral Accumulator: Key Differences

How to Choose the Right Accumulator?

Choosing the right accumulator depends on your production requirements:

📌 Choose Cage Loop if:

• Your mill speed is medium
• Workshop space is limited
• Budget is tight
• Production demand is not extremely high

📌 Choose Horizontal Spiral Accumulator if:

• Your mill runs at high speed
• You need continuous and stable production
• You process large volumes
• You want higher automation and efficiency

💡 Pro Tip:
For modern high-speed ERW tube mills, the horizontal spiral accumulator is becoming the preferred choice.

Frequently Asked Questions (FAQ)

1. Why is an accumulator necessary in an ERW tube mill?

It allows continuous production by storing strip while coils are being welded, preventing downtime.

2. Can I run a tube mill without an accumulator?

Technically yes, but production efficiency will be very low due to frequent stops.

3. Which accumulator is better for high-speed production?

The horizontal spiral accumulator is the best choice due to its large storage capacity and stable strip feeding.

4. Is a cage loop accumulator outdated?

No. It is still widely used for small to medium tube mills due to its cost-effectiveness.

5. What factors affect accumulator selection?

• Tube mill speed
• Strip thickness and width
• Available workshop space
• Budget
• Production capacity