Design and Fabrication of Stainless Steel 316 Process and Storage Tanks for a Detergent Factory in the Kurdistan Region of Iraq

Sahi Rasa, as a specialized industrial design and engineering company focused on turnkey projects, has successfully designed, fabricated, installed, and commissioned more than 100,000 liters of storage and process tanks for one of the largest household detergent manufacturing plants in Sulaymaniyah, Kurdistan Region of Iraq. This project was executed with a precise engineering approach and the mindset of a professional industrial designer — from process studies through to final handover.

Types of Tanks Designed and Fabricated in This Project

In liquid detergent production lines, each tank serves a specific and critical function. Based on the process flowchart, physical and chemical properties of the materials, and safety requirements, the Sahi Rasa industrial design team engineered and delivered the following tank types:

1. Raw Material Storage Tanks
   Various capacities for storing acids, Texapon (SLES), deionized water, salt, and other raw materials. Atmospheric or low-pressure design, equipped with load cells and level control systems.
2. Process and Mixing Tanks
   The main batch production vessels, fitted with mixers, optional heating jackets, and high-precision weighing systems. These tanks form the heart of the production line.
3. Acid Storage and Dosing Tanks
   Fabricated from SS 316L with increased wall thickness and corrosion-resistant connections. Special design for high safety and complete drainage.
4. High-Viscosity / Thick Liquid Tanks
   Dedicated to Texapon and other high-viscosity materials. Featuring conical or sloped bottoms, large nozzles, and suitable pumps for transfer without pressure drop.
5. Finished Product Tanks
   For holding ready detergent liquid before filling. Hygienic design with polished internal surfaces and full CIP capability.
6. CIP (Clean-in-Place) Tanks
   Separate tanks for cleaning solutions, hot water, and final rinse water. Fully integrated with the automatic washing and drainage system.
7. Jacketed Tanks
   Designed with heating jackets (hot water or steam) when temperature control is required during the mixing process.

All tanks were designed for full process integration and direct connection to the plant’s SCADA system.

Technical Design and Fabrication Details (Industrial Designer Perspective)

Material and Surface Specifications

• Shell and connections: Stainless steel grade 316 and 316L (according to ASTM A240)
• Internal surface: Mechanical finish or electropolishing with low surface roughness (typically Ra ≤ 0.8 μm) to prevent product buildup and facilitate cleaning
• Welding: Performed according to ASME Section IX with full quality control (RT and PT at critical points)

Design Standards

• ASME Section VIII Div. 1 for pressure and process vessels
• API 650 for large atmospheric storage tanks
• Wall thickness calculated based on design pressure, operating temperature, and corrosion allowance
• Flanged connections according to DIN or ANSI standards for complete compatibility with the plant’s piping system

Measurement and Control Systems

• Installation of high-precision load cells (typically four per tank) for accurate weight measurement during filling and discharge
• Direct signal transmission capability to PLC and SCADA systems
• Level, temperature, and pressure sensors at strategic points
• Control design allowing operators to execute complete filling, mixing, discharge, and cleaning cycles automatically or semi-automatically via HMI

Automatic Cleaning and Drainage System (CIP)

• Rotating and fixed spray nozzles inside the tanks
• Complete drainage paths with properly sloped bottoms
• Integration with CIP pumps and automatic control system to minimize downtime

Pumps and Transfer Equipment

• Acid-resistant pumps with suitable materials of construction
• Specialized pumps for high-viscosity liquids such as Texapon (SLES)
• Pumps for low-viscosity liquids
• Pump type selection (diaphragm, centrifugal, or progressive cavity) based on viscosity and corrosiveness of the fluid

Mixers / Agitators

• Propeller or anchor agitator design matched to viscosity and tank volume
• Motor and gearbox with appropriate safety factor
• Shaft sealing with mechanical seals resistant to chemical media