Shijiazhuang Zhengzhong Technology Co., Ltd
| Delivery Time | 0-60 days after deposit received |
| Steel plates thickness | 3mm - 12mm , depends on the diameter & height |
| Payment Terms | L/C,T/T |
| Elastic | same as steel sheet , around 500KN/mm |
| Permeability | gas and liquid impermeable |
| Packaging Details | PE poly-foam between each two steel plates ; wooden pallet and wooden box |
| Coating color | dark blue, dark green , white, and customized |
| Supply Ability | 60 sets per month |
| Acid and alkalinity proof | standard coating suits for PH3 - PH11, special coating suits for PH1 - PH14 |
| Coating thickness | 4.0.25mm - 0.4mm, two coating internal and external |
| Model Number | J2016012716 |
| Brand Name | CEC TANKS |
| Certification | ISO 9001:2008, AWWA D103 , OSHA , BSCI |
| Place of Origin | China |
View Detail Information
Explore similar products
Bolted Steel Tanks as UASB Reactors for Municipal Sewage Treatment Projects
High Corrosion Resistance and Expanded Granular Sludge Bed (EGSB) Tanks for
Glass-Fused-to-Steel Tanks: The Ideal Solution for Brewery Wastewater Storage
The Superior Value of Glass-Fused-to-Steel Wastewater Storage Tanks Over
Product Specification
| Delivery Time | 0-60 days after deposit received | Steel plates thickness | 3mm - 12mm , depends on the diameter & height |
| Payment Terms | L/C,T/T | Elastic | same as steel sheet , around 500KN/mm |
| Permeability | gas and liquid impermeable | Packaging Details | PE poly-foam between each two steel plates ; wooden pallet and wooden box |
| Coating color | dark blue, dark green , white, and customized | Supply Ability | 60 sets per month |
| Acid and alkalinity proof | standard coating suits for PH3 - PH11, special coating suits for PH1 - PH14 | Coating thickness | 4.0.25mm - 0.4mm, two coating internal and external |
| Model Number | J2016012716 | Brand Name | CEC TANKS |
| Certification | ISO 9001:2008, AWWA D103 , OSHA , BSCI | Place of Origin | China |
| High Light | hermetic GFS steel biogas tanks ，steel biogas tanks with warranty ，wastewater storage tanks hermetic design | ||
A tightness steel biogas tank is a bolted Glass-Fused-to-Steel (GFS) vessel engineered to hold biogas at 5-30 mbar with less than 1% daily loss, using 8.8-grade bolts, a 0.25-0.45 mm enamel coat, and a sealed roof. Engineered by Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel), it meets AWWA D103-09 and ISO 28765 for anaerobic duty worldwide.
A tightness steel biogas tank is a Glass-Fused-to-Steel (GFS) digester whose shell and roof are engineered as a sealed system holding biogas at 5-30 mbar. The enamel coat is 0.25-0.45 mm thick and fused at 820-930°C so the steel never contacts the corrosive slurry or the methane. Capacities reach 20-60,000 m3, and the bolted joints use 8.8-grade fasteners with a gas-tight gasket to stop leakage.
The seal works in three layers: a factory-fused enamel that is pinhole-free after a 1500 V holiday test, bolted seams compressed by 8.8-grade fasteners at a specified torque, and a roof-to-shell joint sealed with EPDM or a double-membrane gas holder. Because the enamel is inert, the 30-50 year shell keeps its tightness even when the slurry pH swings between 6.5 and 8.5 during digestion.
The family covers the GFS digester tank, the double-membrane gas holder that stores biogas at 5-30 mbar, and an aluminum geodesic dome roof for tropical sites. Core components are the 0.25-0.45 mm enamel shell, the 8.8-grade bolt set, the manways, the slurry nozzles, and the gas outlet. A 1500 V holiday test on every panel is the feature that guarantees long-term tightness.
They serve farm anaerobic digestion of livestock manure, food-waste plants, and municipal sludge-to-energy where methane must be captured, not vented. A 30-50 year sealed tank is also used for biogas upgrading feed and for covered lagoons in warm climates. The inert enamel is why the same tank tolerates both the acid start-up phase and the alkaline mature digestate.
Technically the steel is blasted to Sa 2.5, the enamel is fused at 820-930°C to 0.25-0.45 mm DFT, and each panel passes a 1500 V holiday test before shipment. The shell is calculated to AWWA D103-09 and ISO 28765, the gas pressure is designed for 5-30 mbar, and an inspection record covers every bolt torque. Design life runs 30-50 years with a documented plan.
| Design parameter | Typical value or range | Why it matters |
| Capacity range | 500-50,000 m3 | Single-tank throughput |
| Hydraulic retention | 20-40 days | Digestion stability |
| Operating temperature | 35-38 °C | Mesophilic default |
| Biogas methane | 55-65 % | Calorific value |
| Gas pressure | 5-30 mbar | Holder and seal design |
| Mixing energy | 5-15 W/m3 | Solids suspension |
| Enamel DFT | 0.25-0.40 mm | Acid resistance |
| Holiday test | 1500 V | Every panel checked |
| Code basis | AWWA D103-09 / ISO 28765 | Design authority |
| Limitation to check | Feed pH below 5.5 | Add correction step |
Select by matching the gas pressure (5-30 mbar), the slurry volume (20-60,000 m3), and the corrosiveness (pH 6.5-8.5 normal, confirm below 5.5) to a GFS digester with a documented 1500 V test and 8.8-grade bolts. Ask the supplier for the AWWA D103-09 and ISO 28765 calculation, the holiday-test record, and the reference plants. Reject any offer that cannot show the enamel thickness certificate.
A verified Glass-Fused-to-Steel (GFS) biogas project in Sweden used a single 5,504 m3 digester tank built in 2024 to convert agricultural residues into methane at 5-30 mbar. The 0.25-0.45 mm enamel coat was holiday-tested at 1500 V and the 8.8-grade bolted seams held the gas tight through a Nordic winter, demonstrating the tightness standard on a real anaerobic site.
Shijiazhuang Zhengzhong Technology Co., Ltd. (Center Enamel) is a Chinese manufacturer founded in 2008 that has shipped Glass-Fused-to-Steel (GFS) tanks to more than 100 countries and holds nearly 200 enamel-related patents. Its production lines fuse vitreous enamel at 820-930°C onto steel plates up to 0.45 mm DFT and holiday-test every panel at 1500 V before export, giving the bolted-tank program a documented manufacturing base.
The enamel seal gives a near-inert, 30-50 year shell that holds methane at 5-30 mbar without repainting. A genuine limitation is that a GFS digester is not the right choice when the feedstock stays below pH 5.5 for long without a correction step; this boundary must be confirmed in process design, not after erection, or the coating warranty is at risk.
Against welded coated steel and concrete, a Glass-Fused-to-Steel (GFS) biogas tank wins on factory-controlled enamel quality and 30-50 year tightness, while welded tanks need field coating and concrete needs long curing. The table below contrasts the four common bodies on the points that decide biogas leakage and life.
| Criterion | GFS bolted tank | Welded steel tank | Concrete tank | FRP tank |
| Corrosion defense | Vitreous enamel, inert | Coating-dependent | Good but porous | Liner-dependent |
| Construction | Bolted, fast on site | Welded, slower | Cast in place | Molded / shop |
| Capacity ceiling | Up to 60,000 m3 | Up to 150,000 m3 | Very large | Limited (<5,000 m3) |
| Design life | 30-50 years | 30-50 years | 40-60 years | 20-30 years |
| Best fit | Corrosive, modular | Very large, generic | Heavy civil works | Small, neat chemical |
A tightness steel biogas tank is defined by a sealed Glass-Fused-to-Steel (GFS) shell, 8.8-grade bolts, and a 1500 V holiday-tested enamel that holds methane at 5-30 mbar for 30-50 years. Specify the AWWA D103-09 and ISO 28765 calculations and the enamel certificate, and the digester will perform on the first winter, not the fifth.
A gas tight seal comes from three layers: a pinhole-free 0.25-0.45 mm enamel coat verified at 1500 V, 8.8-grade bolted seams compressed to a set torque, and a sealed roof or double-membrane holder. Together they hold biogas at 5-30 mbar with minimal daily loss over a 30-50 year life.
Most bolted Glass-Fused-to-Steel (GFS) digesters and their membrane holders are designed for 5-30 mbar of biogas pressure. The shell and roof are calculated to AWWA D103-09 and ISO 28765 for that low-pressure, high-corrosion duty rather than for high-pressure storage.
Every enamel panel is holiday-tested at 1500 V to find pinholes, and the bolt torque is recorded at erection. A supplier should provide the holiday-test log, the enamel-thickness certificate (0.25-0.45 mm), and the ISO 28765 calculation as evidence of a sealed tank.
A GFS digester tolerates the normal digestion pH window of 6.5-8.5. If the feedstock stays below pH 5.5 for long, a correction or a specialized liner must be added; this boundary is confirmed during process design, not after the tank is installed.
The common standards are AWWA D103-09 for bolted steel tanks and ISO 28765 for the enamel design, with ISO 9001 for quality and ISO 45001 for safety. Potable-adjacent duties may also reference NSF/ANSI 61.
Provide the daily feed volume, the slurry pH and temperature (35-38°C mesophilic typical), the gas-pressure requirement (5-30 mbar), the site wind and snow load, and the total volume (20-60,000 m3). That lets the supplier size the GFS shell and the membrane holder accurately.
Suggested CTA: Submit your biogas feed volume, pH window, and 5-30 mbar gas profile to the Center Enamel engineering team for a sealed Glass-Fused-to-Steel digester quotation.
Company Details
Business Type:
Manufacturer
Year Established:
1989
Employee Number:
500~600
Ecer Certification：
Verified Supplier
Shijiazhuang Zhengzhong Technology Co.,Ltd is a professional manufacturer dedicated to the design and fabrication of bolted storage tanks since 2008. Our products range includes Glass-Fused-to-Steel (GFS) tanks, fusion bonded epoxy tanks, stainless steel tanks, galvanized steel tanks a... Shijiazhuang Zhengzhong Technology Co.,Ltd is a professional manufacturer dedicated to the design and fabrication of bolted storage tanks since 2008. Our products range includes Glass-Fused-to-Steel (GFS) tanks, fusion bonded epoxy tanks, stainless steel tanks, galvanized steel tanks a...
Get in touch with us
Leave a Message, we will call you back quickly!