Type, characteristics, and applications of pressure vessels

Pressure vessels can be broadly classified into Type 1 pressure vessels and Type 2 pressure vessels. By understanding the characteristics, the optimal pressure vessel can be selected according to the appropriate application.

Differences between Class 1 pressure vessels and Class 2 pressure vessels

Class 1 pressure vessels and Class 2 pressure vessels each have different design standards and regulations, so appropriate selection is required according to the application and the pressure they are handled. Since first-class pressure vessels often handle high-pressure gas, strict safety standards are required by design. For example, reactors and boilers in chemical factories are designed as Type 1 pressure vessels to withstand high temperatures and high pressures and to prevent leakage of contents.

On the other hand, Type 2 pressure vessels often handle lower pressure compared to Type 1, so safety standards are also acceptable. Type 2 pressure vessels are applied to applications that are relatively safe, such as household gas cylinders and compressed air tanks for small and medium-sized enterprises. As a result, cost and ease of installation are often prioritized.

Thus, when choosing a pressure vessel, it is important to carefully consider its application and required pressure conditions. By selecting an appropriate type of pressure vessel, it is possible to achieve efficient operation while ensuring safety. Understanding the difference between Type 1 pressure vessels that handle high pressure and Type 2 pressure vessels that can ensure safety at low pressure is essential for the selection and operation of appropriate equipment.

Applicable categories of Type 1 Pressure Vessels

The Type 1 pressure vessel is a large pressure vessel that does not fall under any of the (simple) containers and small pressure vessels specified in Article 1, Item 5 of the Ordinance for Enforcement of the Industrial Safety and Health Act. Inspection by prefectural labor bureaus at each stage of import, installation, etc. is required. After the start of use, a performance inspection by a registered performance inspection organization is required once a year.

Figures show the application categories in the figure below.

(1) Classification by maximum operating pressure and internal volume


(2) Classification by inner diameter and length of the body (maximum operating pressure ≤ 0.1 MPa)

Classification of Type 2 Pressure Vessels

Type 2 pressure vessel is a pressure vessel specified in Article 1, Item 7 of the Ordinance for Enforcement of the Industrial Safety and Health Act, and is a pressure vessel larger than a (simple) container. It is mandatory to undergo individual certification at the time of manufacture, manufacture or import based on the Type 2 pressure vessel structure standard, and to conduct regular voluntary inspections once a year.

Figures show the application categories in the figure below.

(1) Classification by maximum operating pressure and internal volume

(2) Classification by the inner diameter and length of the torso


Please refer to the following link for detailed information on the applicable categories of various pressure vessels.

・(https://www.jbanet.or.jp/en/examination/classification/vessel-1/) (in Japanese) (in Japanese).

・Applicable categories of Type 2 pressure vessels (Japan Boiler Association) (https://www.jbanet.or.jp/examination/classification/vessel-2/) (in Japanese).

Design standards and safety regulations for pressure vessels

Design standards and safety regulations for pressure vessels are very important to ensure product safety and user reliability. By complying with appropriate standards and regulations, it is possible to reduce risks and prevent accidents.

Domestic and overseas regulatory standards and safety standards

In the installation and operation of pressure vessels, it is necessary to comply with domestic and international regulatory standards and safety standards. These regulatory standards and safety standards are established to prevent accidents and ensure the safety of users. By following this, the risk can be minimized.

For example, in Japan, the inspection and certification of pressure vessels are required under the High Pressure Gas Safety Act. This law confirms that safety standards are met at each stage of manufacturing, installation, and use, and thoroughly implements accident prevention measures. On the other hand, "ASME boilers and pressure vessel codes" are widely recognized internationally and are being complied with in many countries. This code is formulated by the American Association of Mechanical Engineers (ASME) and provides detailed rules from design, material selection, manufacturing and testing.

Points when selecting pressure vessels

1. Operating pressure
2. Internal volume of containers
3. Temperature conditions
4. Purpose of Use and Environment

When selecting a pressure vessel, it is important to select the appropriate size and material according to the purpose. The use of a pressure vessel that does not fit the purpose reduces safety and efficiency and increases the risk of accidents. Therefore, by selecting a material suitable for the application, it is possible to operate reliably over the long term.

For example, chemical factories often handle corrosive substances, so it is recommended to choose a stainless steel pressure vessel with high corrosion resistance. On the other hand, a lightweight and durable aluminum pressure vessel is suitable for air compressors. By choosing the right size and material, safety and efficiency can be ensured and long-term operation is possible.

It is important to maintain and manage pressure vessels regularly to detect problems early. Periodic inspection and maintenance work can detect deterioration and damage of the pressure vessel at an early stage and prevent accidents. In addition, operating costs can be reduced by preventing sudden failures.

Liquid tank (pressure vessel) of Musashi Engineering

The liquid tank of Musashi Engineering is a liquid tank that realizes continuous operation of large flow rate application.

We offer four types of safe lock tanks, straight one-touch tanks, one-touch tanks, and gallon tanks to accommodate a wide range of viscosity, properties, and applications of liquid materials. There are two types of liquid materials: direct input type and inner container type, with a wide range of sizes ranging from 0.5L to 38.5L, so choose the most appropriate tank according to daily usage. Can also be used for Filling liquid agent for syringe.

※We do not manufacture first-class pressure vessels.

Essential components of liquid tank

Points for selecting tank configuration

※The following 124710 corresponds to the number in "Required components of the liquid tank" above.

The size is indicated in the effective volume of the tank. When using material cans or inner containers, be sure to check that the size is large.

For the O-ring, select a material that is difficult to swell according to the material to be inserted.

The suction pipes and liquid tubes vary greatly in diameter and length, respectively, with the flow rate.

⑩Piston for inner containers (for 1kg cans)
It is essential for pumping high viscosity materials.
In the case of grease or viscous adhesives, without pistons, the material is consumed in a mortar shape and cannot be pumped successfully.

The standard specification is a typical 1kg can.
Inner diameter: It is matched to the size of Φ108.
It is also possible to make custom-made products according to the container used by the customer.
　※We will borrow a container (can be used) for measurement.

Options to support easy and secure work

At Musashi Engineering, it is possible to propose solutions for these pressure vessels and application systems incorporating pressure vessels in line with customer needs.

Please feel free to contact us.