In the modern industrial system, the pipeline system is crucial for transporting various media, ensuring the smooth operation of production processes. JIS flanges, as core components for pipeline connections, may seem ordinary but play an irreplaceable role in numerous industrial fields due to their reliable performance. This article will delve deep into JIS flanges, comprehensively interpreting their key characteristics and application values.
I. Definition and Standard System of JIS Flanges
(I) Definition and Basic Concepts
JIS flanges, abbreviated as JS flanges, are pipeline - connecting flanges formulated based on the Japanese Industrial Standards (JIS). In various pipeline systems, they mainly connect the ends of two pipelines, pipe fittings, or equipment through bolts, achieving the dual functions of sealing and fixation to ensure the safe transportation of media. At a microscopic level, the connection of JIS flanges relies on precise tolerance matching and the filling of sealing materials, enabling the pipeline joints to withstand different pressure and temperature conditions.
(II) Relevant Standards within the JIS Standard System
Pipe Material Standards
JIS G3458 stipulates various standards for alloy steel pipes, covering key indicators such as chemical composition, mechanical properties, and dimensional tolerances, providing a basis for the compatibility of alloy steel pipes and JIS flanges. For example, in some chemical pipelines with corrosion - resistance requirements, alloy steel pipes produced according to JIS G3458, when paired with corresponding JIS flanges, can effectively resist medium corrosion.
JIS G3459 specifies the quality requirements and technical specifications for stainless - steel pipes, ensuring the reliability of flange connections in stainless - steel pipeline systems. In the food and beverage industry, stainless - steel pipes combined with JIS flanges not only meet hygiene requirements but also ensure connection stability.
JIS G3468 focuses on large - diameter stainless - steel electric - resistance - welded pipes, meeting the connection needs of large - diameter pipes with JIS flanges under special working conditions. In large - scale water - supply projects for cities, such pipes and JIS flanges are often used for connection.
Flange Standards
JIS B2201 details the pressure ratings of ferritic material pipe flanges, clearly defining the performance limits of flanges under different pressure ratings, which is an important basis for selection. When choosing a flange for a low - pressure heating pipeline, referring to JIS B2201 can accurately determine whether a 2K - rated flange is applicable.
JIS B2202 standardizes the dimensions of pipe flanges, ensuring the interchangeability of flanges produced by different manufacturers, which facilitates the design and installation of pipeline systems. In large - scale factory pipeline renovation projects, there is no need to worry about the compatibility of flanges from different brands.
JIS B2210 provides the basic dimensions of ferritic material pipe flanges, offering accurate data support for the design, manufacture, and inspection of flanges. Manufacturers can efficiently produce compliant flanges based on this standard.
JIS B2220, as a comprehensive standard for steel pipe flanges, comprehensively covers aspects such as flange material selection, dimensional specifications, manufacturing processes, and inspection requirements. From the screening of raw materials to the factory inspection of finished products, this standard is strictly followed.
Pipe Fitting Standards
JIS B2302 standardizes steel threaded pipe fittings, clarifying their structural forms, dimensional tolerances, and connection methods, ensuring the matching accuracy with JIS flanges. In some small - scale maintenance projects, using pipe fittings that meet JIS B2302 and JIS flanges can quickly complete pipeline connections.
JIS B2311 specifies the manufacturing processes, quality requirements, and inspection methods for steel butt - welding pipe fittings for general purposes, ensuring the strength and sealing performance of the connections between pipe fittings and flanges. In oil - transportation pipelines, the connection of such butt - welding pipe fittings and JIS flanges can withstand high pressures.
JIS B2312 and JIS B2313 are the standards for steel butt - welding pipe fittings and steel - plate - made butt - welding pipe fittings respectively, further enriching the types of pipe fittings to meet the needs of different pipeline systems. In building fire - fighting pipeline systems, appropriate pipe fittings can be selected according to actual conditions to connect with JIS flanges.
II. Specification Parameters of JIS Flanges
(I) Nominal Diameter
Nominal Diameter of Seamless Steel Pipes: The range is from DN6 to DN650mm. This series of sizes precisely matches seamless steel pipes, ensuring a tight and reliable connection under different pipe - diameter requirements. For example, in the cooling pipelines of precision instruments, a small - diameter JIS flange of DN6 may be used, while in the material - conveying pipelines of chemical reactors, a large - diameter flange of DN650 is more common.
Nominal Diameter of Welded Steel Pipes: It covers DN350 to DN2000mm, meeting the connection needs of large - diameter welded steel pipes in various projects and ensuring the integrity of the pipeline system. In the drainage pipeline projects of large - scale sewage treatment plants, large - diameter welded steel pipes above DN1000, paired with corresponding JIS flanges, are often used.
(II) Wall - Thickness Representation Methods
Seamless Steel Pipes: The wall thickness is represented by the pipe schedule "Sch". This representation method is based on the corresponding relationship between the nominal diameter and the wall thickness. Through the standard pipe schedule, the required wall thickness under different pressure conditions can be quickly determined to ensure the pressure - bearing capacity of the pipeline. For example, in high - pressure steam pipelines, seamless steel pipes with Sch80 may be selected and paired with corresponding JIS flanges to withstand high temperature and pressure.
Welded Steel Pipes: The wall thickness is directly represented by the wall - thickness value, which is intuitive and concise. It enables engineers to accurately select flanges with appropriate wall thicknesses according to actual working conditions and design requirements, ensuring the stability of welded - steel - pipe connections. In ordinary building water - supply and drainage pipelines, welded steel pipes and JIS flanges with suitable wall thicknesses can be directly selected according to water pressure and pipe diameter.
(III) Nominal Pressure Ratings
JIS flanges have eight nominal pressure ratings: 2K, 5K, 10K, 16K, 20K, 30K, 40K, and 63K. Different pressure ratings correspond to different working environments. 2K and 5K are suitable for low - pressure and normal - temperature conventional industrial scenarios, such as ordinary ventilation pipelines. On the other hand, 63K is designed specifically for extreme working conditions such as high pressure and high temperature. In the high - pressure reaction pipelines of oil refineries, 63K - rated JIS flanges can play an important role. When selecting, it is necessary to accurately match according to the actual working pressure, temperature, and other parameters of the pipeline system to ensure the safe and stable operation of the system.
III. Sealing Surfaces and Types of JIS Flanges
(I) Types of Sealing Surfaces
Smooth Surface: It has a simple structure and is easy to machine. It is suitable for pipeline connections with low - pressure, non - toxic, and non - flammable and non - explosive media, with low cost and convenient installation. In ordinary household tap - water pipelines, smooth - surface JIS flanges are often used.
Large Male Surface and Small Male Surface: By increasing the contact area of the gasket, the sealing performance is effectively improved. They are commonly used in medium - pressure pipeline systems to ensure the stable transportation of media. In the compressed - air pipelines of some factories, JIS flanges with large or small male surfaces are quite common.
Male - and - Female Surface: The male and female surfaces cooperate with each other, effectively fixing the gasket and preventing its displacement. It has good sealing performance and is often used in pipelines transporting toxic, flammable, and explosive media to ensure safety. In the pipelines for transporting hazardous chemicals in chemical parks, male - and - female surface JIS flanges are common choices.
Grooved Surface: An annular groove is machined on the flange surface, and the gasket is embedded in it, greatly improving the sealing reliability. It is suitable for harsh working conditions such as high pressure and high temperature. In the high - temperature and high - pressure steam pipelines of thermal power plants, grooved - surface JIS flanges can ensure the sealing of pipeline connections.
(II) Types of Flanges
Slip - on Type: It is easy to install and has a low cost, suitable for low - pressure and small - diameter pipelines, and is widely used in general industrial pipeline connections. In the simple pipeline systems of small - scale processing plants, slip - on type JIS flanges are widely applied.
Socket - weld Type: The pipe is inserted into the socket of the flange and then welded, with strong sealing performance. It is suitable for small - diameter pipelines and occasions with high requirements for sealing performance. In the infusion pipelines of the pharmaceutical industry, socket - weld type JIS flanges can ensure the purity and safety of drug transportation.
Butt - weld Type: It is connected to the pipeline by butt - welding, with high weld strength. It can withstand high - pressure, high - temperature, and large - diameter pipeline working requirements and is often used in key pipeline systems. In long - distance natural - gas transmission pipelines, butt - weld type JIS flanges are key components to ensure pipeline safety.
Threaded Type: It is connected through threads, which is convenient for installation and disassembly. It is suitable for pipelines that need to be frequently disassembled, but the threaded part is prone to leakage and is not suitable for high - pressure environments. In the movable pipeline devices in laboratories, threaded type JIS flanges facilitate equipment adjustment and maintenance.
Loose - flange Type: The flange is sleeved on the pipeline and fixed through bolts. It is suitable for non - ferrous metal pipelines or scenarios where the pipeline needs to be frequently replaced, with high flexibility. In some workshops where the pipeline layout needs to be adjusted frequently, loose - flange type JIS flanges can meet the requirements.
Blind Flange: It is used to close the end of the pipeline, playing a role in sealing and protection to ensure the integrity of the pipeline system. During the construction of the pipeline system, blind flanges can prevent debris from entering the pipeline.
IV. Application Fields of JIS Flanges
(I) Petrochemical Industry
In the petrochemical industry, JIS flanges are widely used in various raw - material transportation pipelines. Since the media are often corrosive, flammable, and explosive, high requirements are placed on the sealing performance and corrosion resistance of flanges. For example, in the crude - oil transportation pipelines of refineries, JIS flanges with strong corrosion resistance are required. Their diverse sealing surfaces and types can accurately adapt to different working conditions, ensuring the safe and stable operation of the pipeline system.
(II) Power Industry
In the power industry, JIS flanges are commonly used for connecting steam pipelines and water - supply pipelines. Steam pipelines are usually under high - temperature and high - pressure conditions, posing great challenges to the strength and sealing performance of JIS flanges. Take thermal power plants as an example. The high - temperature and high - pressure steam pipelines are connected by JIS flanges. Their high - nominal - pressure ratings and high - quality sealing surfaces can effectively withstand the impact of steam, ensuring the stable operation of the power system.
(III) Pharmaceutical and Food Industries
In the pharmaceutical and food industries, JIS flanges are used in pipelines for transporting drugs and food. Due to their smooth surface and resistance to dirt accumulation, they can strictly meet hygiene standards, effectively ensuring the quality and safety of drugs and food. In food and beverage production enterprises, the application of JIS flanges in the pipeline system from raw - material transportation to finished - product filling ensures that the food is not contaminated.
V. Relationship between JIS Flanges and Other Standard Systems
(I) Differences from ANSI and DIN Standards
The JIS standard system has significant differences from the ANSI (American National Standards Institute) and DIN (Deutsches Institut für Normung e.V.) standard systems. In terms of flange dimensions, sealing - surface forms, and pressure - rating divisions, each standard system has different regulations and cannot be directly used in combination. For example, the flange dimensions and pressure - rating settings of the ANSI standard are different from those of the JIS standard, and the sealing - surface forms and connection methods of the DIN standard also differ from those of the JIS standard. In transnational projects, if these differences are not noted, problems may occur in pipeline connections.
(II) Role of the JPI Standard
To address the issue of integration with international standards, the Japan Petroleum Institute has developed the JPI standard. This standard is equivalent to the ANSI/API application standard system, enabling interchangeability with ANSI standards. In international projects such as those in the petrochemical industry, JPI - standard flanges can meet the requirements of being used in combination with ANSI standards, enhancing the universality of JIS flanges in the international market. For example, in some international cooperation offshore oil - exploration projects, JPI - standard JIS flanges can be used in conjunction with ANSI - standard pipe fittings.
Among numerous JIS flange brands, EATHU stands out. EATHU focuses on the research, development, and production of JIS flanges, strictly following the JIS standard system and strictly controlling every production process. Its products not only excel in dimensional accuracy, perfectly fitting various pipelines, but also demonstrate outstanding sealing performance and durability. Whether facing the complex working conditions of the petrochemical industry or the special requirements of the power, food, and other industries, EATHU JIS flanges can provide a solid guarantee for the stable operation of pipeline systems with their reliable quality and are a trustworthy brand choice.
JIS flanges, with their unique standard system, rich specification parameters, diverse sealing surfaces, and types, occupy an important position in the field of industrial pipeline connections. In - depth understanding of relevant knowledge about JIS flanges is of great guiding significance for the design, installation, and maintenance of industrial pipeline systems, helping to ensure the efficient, safe, and stable operation of industrial production. With the continuous progress of industrial technology, JIS flanges will also continue to be optimized and upgraded, contributing more to industrial development
