What is a high-pressure pipeline? How many kilograms of pressure does a high-pressure pipeline refer to? Which pipelines/industries usually require high pressure? How to repair a high-pressure pipeline leak? The following editor summarizes the answers to these questions for you

1. What is a high-pressure pipeline?

"High-pressure pipeline" refers to a pipeline system that operates under engineering requirements with a higher design pressure. The "high pressure" here is a relative concept, and the specific numerical limit will vary according to different industry standards, national specifications and the medium transported by the pipeline. The high design pressure refers to the maximum internal pressure that the pipeline is expected to withstand during design, which is much higher than normal pressure (atmospheric pressure).

2. How many kilograms of pressure does high-pressure pipeline refer to?

In China, according to GB/T 20801 "Pressure Pipeline Specification Industrial Pipeline":
      🔹  Low pressure (L): 0 MPa < P ≤ 1.6 MPa         0 kg pressure < P ≤ 16 kg pressure
      🔹  Medium pressure (M): 1.6 MPa < P ≤ 10.0 MPa      16 kg pressure < P ≤ 100 kg pressure
      🔹   High pressure (H): 10.0 MPa < P ≤ 100.0 MPa     100 kg pressure < P ≤ 1000 kg pressure
      🔹   Ultra-high pressure (U): P > 100.0 MPa              P > 1000 kg pressure
Therefore, it is generally believed that the design pressure > Pipelines with a pressure of 10.0 MPa (about 100 atmospheres) are high-pressure pipelines. Different industries have their own divisions. For example, in the field of long-distance oil and gas pipelines, design pressures > 6.3 MPa or > 10 MPa may be considered high pressure. In thermal power plants, steam pipeline pressures may be as high as 25-30 MPa or even higher.

3. Which pipelines/industries usually require high pressure?

Pipelines that require high pressure usually serve specific process requirements or economic benefit goals, mainly concentrated in the chemical and petrochemical industries, power industry (thermal power generation), oil and gas industries, industrial gas production and transportation, hydraulic systems, nuclear power plants, water jet cutting, and urban water supply pipelines in mountainous areas:

1. 🧿Chemical and petrochemical pipelines:
Synthetic ammonia, synthetic methanol: The operating pressure of the core reactor (such as an ammonia synthesis tower) is usually 15 - 30 MPa or even higher. The corresponding feed pipelines) and discharge pipelines are all high-pressure pipelines.
Hydrocracking, hydrofining: reaction pressure can reach 10 - 20 MPa. Hydrogen feed pipelines and reactor inlet and outlet pipelines are typical high-pressure pipelines.

High-pressure polyethylene: polymerization reaction pressure can reach 100 - 300 MPa. Reactor pipelines and compressor inlet and outlet pipelines are subject to extremely high pressure. 
Urea synthesis: synthesis pressure is 15 - 25 MPa. 
Catalytic reforming: reaction pressure is usually 1 - 3 MPa, but some processes or hydrogen circulation system pressures may be higher. 
High-pressure gas separation: such as high-pressure oxygen and nitrogen pipelines in air separation units.

2.🧿 Power industry, thermal power generation pipelines:
Main steam pipeline: pipeline connecting boiler outlet and turbine inlet. The steam pressure of supercritical and ultra-supercritical units can reach 25 - 30 MPa or even higher, and the temperature exceeds 600°C.
Reheat steam pipeline: The pipeline from the outlet of the boiler reheater to the inlet of the intermediate pressure cylinder of the steam turbine. Although the pressure is lower than that of the main steam, it is also quite high.

High-pressure feed water pipeline: The pipeline from the outlet of the feed water pump to the inlet of the boiler economizer. The pressure needs to overcome the internal resistance of the boiler. It is usually much higher than the working pressure of the boiler and can reach 20-40 MPa.

3. 🧿Oil and natural gas industry pipelines:
Long-distance gas pipelines: In order to improve the transmission efficiency and economic benefits, the trunk gas transmission pressure is usually designed to be very high, with a common range of 6-12 MPa. Some key sections or specific designs may be higher (reaching 10-15 MPa or even higher). This is one of the most common high-pressure pipeline applications. 
Natural gas gathering pipeline: The pipeline from the gas well to the processing plant. The pressure depends on the gas reservoir pressure. The gathering pipeline pressure of the high-pressure gas field may be very high. 

Gas/water injection pipeline: A pipeline for injecting high-pressure gas or water into an oil reservoir to increase the recovery rate. The pressure must overcome the formation resistance and can reach 10-30 MPa or higher. 
Subsea pipeline: The development of deepwater oil and gas fields requires high-pressure transportation to overcome the water depth pressure and seabed resistance. 
CNG filling station: The pressure of the storage and filling pipeline in the station is usually 20-25 MPa.

4. 🧿Other industrial pipelines:
Industrial gas production and transportation of high-pressure oxygen, nitrogen, argon, hydrogen and other pipelines. 
Water jet cutting: Ultra-high pressure water pipeline from booster pump to cutting head, the pressure can reach 00-400 MPa. 
Hydraulic system: Hydraulic power pipeline of large machinery, the pressure can reach 30-70 MPa. 
Nuclear power plant: Pipelines of some systems (such as the main coolant pipeline of pressurized water reactor) also work under high pressure.

4. How to repair a high-pressure pipeline leak?

Once a high-pressure pipeline is damaged, it will bring huge losses. High pressure means that there is huge energy stored in the pipeline. Once a leak or rupture occurs, the energy will be released instantly, which may cause explosions, fires, diffusion of toxic media, equipment damage, building collapse, shock waves, debris, and the medium itself (high temperature, toxic, flammable) will cause heavy casualties. 

The requirements for transporting high-pressure gas and liquid pipelines are very high. Materials with high strength, high toughness, good welding performance and resistance to medium corrosion must be selected. Wall thickness calculation, stress analysis, flexibility analysis, support design, etc. must be very rigorous and comply with relevant specifications.

After the high-pressure pipeline is damaged, a high-pressure pipe repair clamp(coupling) made of carbon steel can be used for repair. Changzhou Baoshuo Pipe Fittings High-pressure pipe repair clamp(coupling) can design a pipe repair clamp(coupling) that can withstand the corresponding pressure according to the different pipeline pressures. Usually, after the high-pressure pipe repair clamp(coupling) is installed, it needs to be pressure tested. The repair is completed only after the corresponding pressure requirements are met.

Due to long-term use and aging of pipelines, leakage occurs. Generally, pipelines can be repaired using molded half joints. However, when the pipeline pressure reaches more than 1.6MPa, it is difficult to find suitable products. Generally speaking, 0.1MPa of water gushes out at a height of 1m. You can roughly estimate the pipeline pressure. Repairs above 2.0mpa  will be dangerous. Our company has many years of experience in producing pipe repair clamp(coupling). Based on the trust of our customers, our customers have customized a large number of high-pressure pipe repair clamp(coupling) for us. The specifications range from 2MPa to 6MPa and the lengths are different. There are all kinds of pipe diameters. We have a professional team of designers and decades of experience in producing pipe repair clamp(coupling).