Storage Tank Design and Importance of Various Openings

Storage tanks are crucial for safely storing gases and liquids, and the design of internal openings plays a vital role in ensuring their storage function, ease of operation, and safety. Different types of openings not only fulfill specific functional needs but also guarantee the stability of the storage tank under high pressure and in special environments. This article will analyze the types, functions, design features, and practical importance of various openings in storage tanks.

Probe Holes

Probe holes, also known as liquid level measurement ports, are essential accessories in storage tanks for gauging gas levels and sampling. Key characteristics and functions include:

1. Location and Specifications

Probe holes are typically positioned at the top of the storage tank, with a diameter of 150 mm. This design allows easy access for operators near the tank ladder platform. The location facilitates accurate liquid level measurements and convenient operation for personnel.

2. Sealing Design

These openings feature a sealable cover and tightening bolts to ensure excellent sealing performance, preventing external air and harmful substances from entering the tank. This design significantly enhances the safety of the storage tank by reducing the risk of gas leaks.

3. Safety Measures

To prevent sparks from collisions when closing the cover, a gas-resistant rubber pad or soft metal (such as copper or aluminum) is placed beneath the probe hole. Additionally, the inner side of the opening is lined with copper or aluminum alloy to minimize the risk of fire caused by static electricity. This design is particularly important in high-pressure environments, ensuring the safety and reliability of the probe hole under hazardous conditions.

Manholes

Manholes provide a passage for cleaning and maintaining the storage tank, primarily serving as a safe entry and exit point for operators. Design features and significance include:

1. Specifications and Location

Manholes typically have a diameter of 600 mm and are positioned on the lower section of the tank wall, opposite the light transmission holes on the tank top. This arrangement ensures that operators can conveniently access the tank for cleaning and maintenance while providing good visibility for the task.

2. Number Configuration

Depending on the tank's capacity, there may be one or two manholes. For example, tanks below 3,000 cubic meters usually have one manhole, while those above 5,000 cubic meters must have at least two to ensure adequate space and ease of operation. Such configurations offer greater flexibility for maintenance personnel and enhance safety during emergency evacuations.

3. Maintenance and Safety

The design of manholes not only facilitates cleaning and maintenance but also serves as an emergency escape route in the event of a leak or accident. Thoughtful positioning and quantity of manholes can effectively reduce safety risks for personnel during incidents.

Light Transmission Holes

Light transmission holes, primarily provide lighting and ventilation for cleaning and maintenance. Their design features and functions include:

1. Location and Specifications

Light transmission holes are typically located at the top of the storage tank, with a diameter of about 500 mm, positioned 800 to 1,000 mm from the tank wall. The number of light transmission holes usually matches the number of manholes, ensuring effective ventilation and lighting during maintenance, thus lowering safety risks for workers.

2. Enhanced Visibility

Light transmission holes not only improve the working environment for operators but also assist in quickly identifying problems during inspections by allowing light in. This is particularly crucial for operators working in low-light conditions, helping them promptly detect any abnormalities within the tank and reducing the risk of accidents.

Cleaning and Drain Holes

Cleaning holes and drain holes are essential for maintaining cleanliness and discharging waste within the storage tank. Their specific functions are as follows.

1. Cleaning Holes

These are used for washing out heavy oils and other viscous liquids, ensuring the tank's interior remains hygienic and minimizing sediment and impurities. Regular cleaning prevents sediment buildup, thus preserving the quality of the liquid in the tank and ensuring long-term safety.

2. Drain Holes

Designed for discharging light oils, these holes facilitate timely replacement and removal of liquids, preventing deterioration from prolonged storage. Common specifications for cleaning and drain holes include DN50, DN80, and DN100 to meet various operational needs. This design helps maintain the cleanliness of the storage tank, reducing safety risks from deteriorating oil products.

Vent Holes

Vent holes prevent the accumulation of oil and gas within the storage tank and are crucial for ensuring safety. Key features include:

1. Design and Setup

In floating roof tanks, the internal floating plate covers the oil surface, significantly reducing gas space. Therefore, the tank top usually lacks mechanical breathing valves and safety valves. However, vent holes are installed on the tank top and wall to maintain pressure balance inside and outside the tank, preventing dangerous gas buildup. The design of vent holes not only avoids risks from excessive pressure but also ensures gas circulation within the tank.

2. Preventing Safety Hazards

The design of vent holes is vital for reducing accident risks, ensuring the safe operation of the storage tank, and preventing severe incidents such as fires or explosions caused by gas accumulation. Regular checks and maintenance of these holes are essential for their proper functioning and enhancing the safety of the storage tank.

Conclusion

The design of various openings in storage tanks is well-considered, ensuring the safe storage of gases and liquids while facilitating convenient operations. Through the thoughtful arrangement of probe holes, manholes, light transmission holes, cleaning holes, drain holes, and vent holes, storage tanks can effectively meet production needs while minimizing potential safety risks. Operators should regularly inspect and maintain these openings to ensure the safe and reliable operation of storage tanks.