10 Steps to Specify an ERW Tube Mill: Tube Size to Full Line
Choose the mill model from your maximum OD and wall thickness, then use strip, material, coil, speed, cutting, power and site data to define the full line.
Read articleStrip storage for straight-seam ERW tube mills · horizontal and floor type
Spiral Accumulators
A spiral accumulator supplies stored strip during coil changes and joining. Available running time depends on usable storage, line speed and the joining cycle. Also known as a looper.
Its role in production
Illustrative render Its place in the line“Spiral” refers to the strip coiled in spirals inside the accumulator. It serves straight-seam ERW tube mills and is not equipment for spiral-welded pipe.
A spiral accumulator supplies stored strip to the downstream mill during coil changes and strip joining at the entry. When storage and the joining cycle are matched, the mill can continue while entry feeding pauses. The available running time depends on usable storage and line speed.
We build two types; both store the strip by winding it on edge into a spiral. In the horizontal (disc) accumulator, one main motor turns the disc; it is compact and suits small to medium widths and thinner strip. The floor-type accumulator has a fixed base and driven outer rollers; it has a large storage capacity and suits wide, thick strip and large mills. Usable stored length needs to be calculated for the specific structure, storage zone and strip conditions. The width and thickness range of each size is in the table below.
Required storage length is calculated from line speed and coil-change time, not from machine size alone: the faster the line and the slower the change, the more strip the accumulator must hold. Please tell us the strip width, thickness and material, the target line speed, the time a coil change takes, and the floor space and entry and exit directions available.
The spiral accumulator is one of the first products the company developed in-house. It is supplied with the uncoiler, leveler and shear and butt welder as the entry section of a tube mill, or on its own.
Base storage calculations on usable strip, distinguishing total capacity, material that can be released during operation and any agreed reserve. Consumption during a coil change depends on line speed and interruption duration. If the mill continues to run, replenishment requires entry speed to exceed exit speed; at constant speeds, the net refill rate is entry speed minus exit speed.
Space planning should include strip paths, threading and maintenance access, as well as the permitted bending conditions for the material. Once the design is confirmed, the agreed trial-run checks should use the actual strip and cover the storing and releasing process, coordination with the upstream joining equipment, and the handling of abnormal operating states.
Used in these lines Tube mill lines · 12 models, complete lines
Photographs
Technical specifications and the two designs
Actual specifications depend on the material and final equipment configuration.
- Strip width
- 20–2400 mm
- Strip thickness
- 0.4–22 mm
- Horizontal accumulator Diameter Φ2–6.5 m 12 sizes
- Floor-type accumulator Diameter Φ4–20 m 16 sizes
| Type | Diameter m | Model | Strip width mm | Strip thickness mm |
|---|---|---|---|---|
| Horizontal accumulator | Φ2 | YJHT-2M | 20–80 | 0.4–1.5 |
| Φ2.5 | YJHT-2.5M | 60–180 | 0.4–2.0 | |
| Φ3 | YJHT-3M | 60–220 | 0.4–2.5 | |
| Φ3.5 | YJHT-3.5M | 60–240 | 0.6–3.0 | |
| Φ4 | YJHT-4M | 60–350 | 0.8–3.0 | |
| Φ4.2 | YJHT-4.2M | 80–400 | 1.0–3.5 | |
| Φ4.5 | YJHT-4.5M | 100–450 | 1.0–4.0 | |
| Φ4.8 | YJHT-4.8M | 100–450 | 1.0–4.5 | |
| Φ5 | YJHT-5M | 120–550 | 1.0–4.5 | |
| Φ5.5 | YJHT-5.5M | 150–600 | 1.2–5.0 | |
| Φ6 | YJHT-6M | 180–650 | 1.5–5.5 | |
| Φ6.5 | YJHT-6.5M | 180–700 | 1.5–6.0 | |
| Floor-type accumulator | Φ4 | YJLD-4M | 60–350 | 0.5–3.0 |
| Φ5 | YJLD-5M | 120–550 | 1.0–4.5 | |
| Φ6 | YJLD-6M | 180–650 | 1.5–5.5 | |
| Φ7 | YJLD-7M | 200–800 | 2.0–7.0 | |
| Φ8 | YJLD-8M | 250–800 | 2.5–8.0 | |
| Φ9 | YJLD-9M | 300–1050 | 3.0–9.0 | |
| Φ10 | YJLD-10M | 300–1250 | 3.0–10.0 | |
| Φ11 | YJLD-11M | 300–1400 | 4.0–12.0 | |
| Φ12 | YJLD-12M | 300–1400 | 4.0–13.0 | |
| Φ13 | YJLD-13M | 400–1400 | 6.0–14.0 | |
| Φ14 | YJLD-14M | 400–1400 | 6.0–15.0 | |
| Φ15 | YJLD-15M | 500–1600 | 6.0–16.0 | |
| Φ16 | YJLD-16M | 500–1600 | 6.0–17.0 | |
| Φ17 | YJLD-17M | 500–1800 | 6.0–18.0 | |
| Φ18 | YJLD-18M | 500–2200 | 6.0–20.0 | |
| Φ20 | YJLD-20M | 600–2400 | 8.0–22.0 |
Source: company product catalogue (April 2025 edition), page 10.
Start the equipment discussion with these requirements
Use these points to prepare the equipment discussion. Specifications and configuration depend on the project.
- Strip width, thickness and material
- Target line speed
- Time needed for one coil change
- Horizontal or floor type, and floor space available
- Entry and exit directions and position of neighboring machines
Continue along the line
Tell us your material, tube profile and output
We discuss the suitable model and configuration for your product and plant. Every line is configured per project, and pricing follows the configuration.