In the global midstream and refining sectors, the ability to effectively blend crude oil—adjusting density, sulfur content, and viscosity—is a critical economic driver. Shijiazhuang Zhengzhong Technology Co., Ltd (Center Enamel), a premier China Carbon Steel Blended Crude Oil Tanks Manufacturer, provides the specialized engineering required to transform static storage into active processing infrastructure.
Our Welded Steel Tanks are designed to meet the rigorous demands of terminal storage infrastructure, where high variability in fluid properties and corrosive sediments require uncompromising structural integrity and advanced mechanical systems.
Choosing the correct steel grade is the foundation of a safe blending terminal. We select specific ASTM grades based on the operational pressure and thermal profile of the blending process.
Feature | ASTM A36 | ASTM A516 Grade 70 |
Primary Use | Atmospheric Storage / General Purpose | Low to Moderate Pressure Blending |
Tensile Strength | 400 – 550 MPa | 485 – 620 MPa |
Key Advantage | High weldability and cost-efficiency | Superior notch toughness and pressure resistance |
Primary Application | API 650 standard crude oil tanks | API 620 tanks for higher vapor pressures |
Corrosion Performance | Excellent base for epoxy liners | High density prevents hydrogen blistering |
In crude oil blending, the accumulation of BS&W (Bottom Sediment & Water) is an inevitable hurdle. When different crude grades are homogenized, heavier solids and emulsified water settle, creating a highly corrosive "sludge" layer that can lead to localized pitting and microbial-induced corrosion (MIC).
● Sloped Floor & Sump Design: Unlike flat-bottom tanks, our carbon steel tanks utilize a coned-down or sloped floor geometry. This directs corrosive saltwater and sediments toward a central low-point sump for efficient removal, protecting the steel floor from long-term aqueous contact.
● Internal Lining for Sour Service: For "sour" crude containing Hydrogen Sulfide (H2S), we recommend a thick-film glass-flake reinforced epoxy or novolac epoxy coating for the tank floor and the bottom 1–2 meters of the shell to prevent hydrogen-induced cracking (HIC).
Successful crude oil homogenization requires high-intensity agitation and precise viscosity management, particularly when dealing with heavy crude grades.
Blending requires high-torque agitation, which introduces dynamic loads and vibration into the tank shell. To prevent localized fatigue:
● Side-Entry Mixer Reinforcement: We incorporate specialized side-entry mixer reinforcement including thickened insert plates and reinforced nozzles in accordance with API 650 Annex C. This ensures the vibration from mixing propellers does not compromise the tank's structural lifespan.
Maintaining a consistent temperature is critical for both homogenization and pumpability.
● Thermal Fluid Heating Systems: We engineer tanks to support internal heating coils or suction heaters. By using suction heaters at the outlet, operators can heat only the oil being transferred, significantly reducing energy costs for the facility.
To manage volatility and protect the crude asset, Center Enamel integrates high-performance roof systems.
● Volatility Control: Our tanks seamlessly integrate with Internal Floating Roofs (IFR) to minimize vapor space and VOC emissions.
● Aluminum Dome Roofs: These geodesic structures are lightweight and highly corrosion-resistant. They provide a maintenance-free external seal that protects internal floating roofs from weather, debris, and environmental ingress, adding significant lifecycle value to the terminal storage infrastructure.
Q: What is the best heating system for high-viscosity crude blending?
A: Thermal Fluid Heating Systems (Indirect Heating) are the industry standard. Circulating hot oil through internal coils provides a steady heat source without the risk of "coking" associated with direct-fired systems.
Q: How does side-entry mixer torque affect tank shell thickness?
A: High torque exert significant dynamic loads. Under API 650, we must increase the insert plate thickness and add nozzle reinforcements to prevent stress cracking and vibration-induced fatigue.
Q: Does carbon steel need internal lining for sour crude oil?
A: Yes. Internal lining is highly recommended for the bottom sections where BS&W settles. A novolac epoxy coating acts as a chemical barrier against H2S, preventing sulfide stress corrosion.
