Higher Structural Rigidity
The steel shell resists wind, snow, and external mechanical loading, giving the holder a more stable overall form.

The external-steel internal-membrane holder uses a steel shell for structural loading and an internal membrane for gas-tight separation. It suits projects with stricter demands on appearance, weathering, and design pressure.
Product Overview
The external-steel internal-membrane holder uses a steel shell for structural loading and an internal membrane for gas-tight separation. It suits projects with stricter demands on appearance, weathering, and design pressure.
It is often selected for urban projects, industrial parks, and standardized facilities where storage performance must also fit the surrounding built environment.

Core Advantages
Built around stable operation, efficient installation, and lower long-term maintenance risk for industrial projects.
The steel shell resists wind, snow, and external mechanical loading, giving the holder a more stable overall form.
Its clean elevation and paintable façade make it suitable for projects with stronger demands on site image and visual coordination.
Where higher pressure stability or special downstream duty is required, the external-steel format is easier to reinforce by design.
Platforms, ladders, and peripheral equipment connect more naturally to the overall steel structure.
Technical Specifications
| Typical Volume Range | 300-30,000 m3 |
| Design Pressure | 5,000-30,000 Pa |
| Shell Material | S235 / S355 carbon steel or equivalent |
| Corrosion Protection | Hot-dip galvanizing or coating system |
| Structure | Steel shell + internal membrane separation |
| Service Life | 15-20 years |
Safety Design
Level 1 Protection
Mechanical safety valves provide first-response protection and reduce peak load on the shell and membrane.
Level 2 Protection
Pressure, temperature, and blower or valve states are monitored together to keep pressure control precise.
Level 3 Protection
Hard interlocks with flare, power generation, and process headers trigger shutoff, relief, or switchover according to defined logic.
Structural Design
A dual-channel air path creates more even membrane support pressure inside the shell, improving stability and dynamic response on large-diameter units.
Material Standards
The steel shell and membrane system have clearly separated roles for targeted optimization.
The outer anti-corrosion system can be specified to match local exposure class.
Platforms, ladders, and access points integrate naturally with the steel structure.
Main Structure
| Outer Shell | Rolled steel shell, coated or galvanized |
| Internal Membrane | Gas-tight PVDF-coated membrane system |
| Corrosion Protection | Galvanizing / epoxy-rich primer / top coat |
| Accessories | HDG steel, SS304, SS316, or FRP on request |
Membrane Performance
| Membrane System | High-barrier gas-tight membrane |
| Methane Permeability | < 28 cm3/(m2·day·atm) at 23°C |
| Pressure Adaptability | Designed for reinforced pressure duty |
| Fatigue Resistance | Suitable for long-term cyclic service |
| Weather Resistance | Matched to steel-shell outdoor service |
| Welding Method | Controlled hot-wedge welding process |
Project Inquiry
Send the capacity, site conditions, and preferred finish or structure, and we will prepare a project-specific recommendation.
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