In industrial equipment and pipeline systems, there is a seemingly inconspicuous but vital element-it can withstand high temperature and pressure, and it can expand and contract like a spring; It can not only protect the pipeline from being cracked by thermal stress, but also isolate vibration and reduce noise. This is the expansion joint. So, what areas are expansion joints used? This article will take you through the application layout of expansion joints.

1. Traditional industrial field: the "basic disk" of expansion joint

1. Petrochemical sector

Petrochemical industry is one of the most widely used areas of expansion joints. High temperature reactors, catalytic cracking units, heat exchangers, storage tank areas, etc. in oil refining units all require expansion joints to absorb thermal displacement and mechanical vibration during equipment operation。

Take the procurement project of Sinopec Hainan Refining and Chemical as an example. Its expansion joint procurement covers many links such as reforming unit, aromatic hydrocarbon unit, storage and transportation tank area, refined oil terminal, etc. The procurement specifications range from DN80 to DN800, and the pressure grade covers 0.6MPa to 3.5MPa. The materials include 20#carbon steel, 316L stainless steel, N08800 nickel-based alloy, etc。 This speaks volumes about the huge demand for expansion joints in the petrochemical industry.

In oil pipelines, rubber expansion joints also resist sulfide corrosion and absorb pressure shocks。

2. Electricity and energy field

In which areas the expansion joint is used, the power industry occupies an important position. Boiler flue, desulfurization and denitrification system, steam turbine pipeline, induced draft fan inlet and outlet of thermal power plant all need a large number of expansion joints to absorb thermal displacement and isolate vibration。

The nuclear power field is also inseparable from expansion joints. Sichuan Kaiman Nuclear Power Equipment Company specially developed rubber expansion joints for negative pressure pipelines in nuclear power plants, which achieved rapid rebound and axial/radial compensation compression。

The LNG (liquefied natural gas) industry is an emerging field for expansion joint applications. The LNG low-temperature expansion joint product developed by Shuangrui Special Equipment of 725th Institute of China State Shipbuilding Corporation has been successfully equipped with 174,000 cubic meters of large LNG carriers, realizing the first application of domestic LNG low-temperature expansion joint on large LNG carriers。

3. Metallurgy and nuclear energy

In the iron and steel metallurgy industry, high-temperature flue gas and hot air ducts need high-temperature resistant expansion joints; In the field of nuclear energy, expansion joints are used in piping systems of nuclear reactors, which require extremely high reliability and safety。

II. Architecture and Municipal Engineering Field

1. Heating and HVAC

In the heating system of northern cities, the expansion joint is the key equipment to ensure the safe operation of heating pipelines. Heating pipes will produce significant thermal elongation when the temperature rises. In order to prevent deformation or damage of the pipes due to thermal stress, expansion joints must be provided on the pipes。

In the field of HVAC, rubber expansion joints are widely used in the inlet and outlet pipes of water pumps, fans, water chillers and other equipment, and have the functions of reducing noise, reducing vibration and compensating pipe displacement。

2. Water supply, drainage and fire protection

Expansion joints are needed to absorb vibration and displacement at water pump outlets and pipe turns in water feed and drainage systems. Rubber expansion joints are also heavily used in pump room pipes in fire protection systems。

Environmental Protection and Flue Gas Treatment

With the improvement of environmental protection requirements, desulfurization and denitrification system has become an important application field of expansion joint. In wet flue gas desulfurization system, non-metallic expansion joints are widely used in the flue at the inlet and outlet of absorption towers because of their excellent acid and alkali resistance。

The main material of non-metallic expansion joint is fiber fabric and heat insulation cotton, which has the functions of sound absorption and vibration isolation, and can effectively reduce the noise and vibration of boiler, fan and other systems。

IV. Transportation and Shipbuilding

1. Shipbuilding

Expansion joints are required for ship smoke exhaust pipe system, ballast water system, fuel system, etc. The 725th Institute of China State Shipbuilding Corporation has specially formulated the standard for marine expansion joints-CB 1153-95 Metal Corrugated Expansion Joints (Marine Use)。

LNG carriers are one of the "three jewels in the crown" of shipbuilding. The LNG low-temperature expansion joint products developed by Shuangrui Special Equipment are faced with severe working conditions such as huge temperature difference, severe ocean corrosion, violent vibration and sway, etc. Previously, it has been imported for a long time, and now it has been made in China。

2. Cars and Engines

Automotive exhaust pipes, engine intake and exhaust systems also need expansion joints to absorb thermal expansion and vibration.

V. Emerging fields: AI data center liquid cooling

The latest answer to which areas expansion joints are used is – AI data centers.

At present, AI large models are moving towards trillion-level parameters. The power of a single cabinet in data centers has soared from the traditional 5kW-10kW to 60kW-100kW, and even exceeded 130kW in high-end scenarios. Traditional air cooling can no longer meet the demand for heat dissipation, and liquid cooling technology has become the mainstream scheme。

Chuanhuan Technology has developed liquid-cooled expansion joint products for the liquid-cooled scenario of high-density data center. As the core flexible buffer component of liquid cooling pipeline system, this product can effectively realize multi-dimensional thermal displacement absorption, system pressure fluctuation buffer, equipment vibration transmission block and installation deviation compensation, and can be adapted to a wide temperature range of-40℃ to 120℃, and working pressure of 0MPa to 2.5MPa。

Other professional fields

1. Aerospace

Special working conditions such as rocket propellant pipeline and aircraft fuel system require special expansion joints. There is also a special standard in the space field-QJ811-83。

2. Pharmaceutical and food

The pharmaceutical and food industries have high requirements for pipeline hygiene, and stainless steel expansion joints are widely used because of their smooth inner walls, no dead corners and easy cleaning。

3. Paper and Textiles

Expansion joints are needed to compensate for thermal displacement and isolate vibration in steam pipes, pulp conveying pipes in paper mills and hot air pipes in textile mills。

SUMMARY OF APPLICATIONS IN EVERY

sum up

The answer to which fields expansion joints are used can be summarized in one sentence: expansion joints can be seen in almost all industrial and civil fields with fluid transport and temperature change.

From traditional petrochemical industry, electric energy, metallurgical nuclear energy, to building HVAC, water supply and drainage and fire protection; From shipbuilding, transportation, to emerging AI data center liquid cooling; From aerospace to pharmaceutical food-as the "flexible joint" of pipeline system, expansion joint silently guards the safety and operation stability of equipment in all walks of life。

With the continuous advancement of technology, the materials and processes of expansion joints are continuously upgraded. Nickel-based alloy is used for high temperature and high pressure, fluororubber is used for strong corrosive flue gas, low temperature special materials are used for LNG ultra-low temperature working conditions, and silicone rubber is used for extreme cold environment at-60℃。 Nowadays, the expansion joint is moving from "industrial supporting role" to more emerging fields, and has become an important basic component to ensure the safe operation of modern industry.