How to Manage the Quality Control of Chemical Industry Pipeline?

For chemical plants, equipment, process pipelines that transport raw materials, water, gas, and finished products, stainless steel pipe fittings and valves that control the flows are important. Therefore, at the beginning of the project construction, the quality of the process pipeline installation must be strictly controlled. To control the construction quality of the process pipeline, we need to control the whole process from the start of construction preparation to the end. We can divide the process into the following three stages.

Chemical Industry Pipeline Preparation Stage 

If we want to understand the characteristics of the process construction of this project and determine the construction difficulties and the main parts that are prone to quality problems, we should generally start from the following aspects.

1. Organization

Establish a quality assurance system, organizational structure and quality management system, clarify the quality responsibilities of each management department, and implement the responsible person.

2. Technical Aspects

Be familiar with the construction drawings, understand the main function of each equipment of the construction device from the flow chart, combine the pipeline characteristics list, and be familiar with the various process pipelines connected between the equipment.

3. Staff Training

According to the pipeline design material of this project, the welding procedure specification is compiled, the qualified welding procedure assessment that meets the specification requirements is made, and the welder is trained.

4. Material Procurement

According to the materials, specifications, models and standards required by the material preparation plan, qualified material suppliers with processing and manufacturing capabilities and manufacturing qualifications should be selected.

5. Acceptance of Welding Materials

The appearance of the package should not be damaged or damp, and the marking on the package should be consistent with the attached quality certification documents. If it is inconsistent, it must be re-examined.

Chemical Industry Pipeline Installation Process

Before construction, engineering and technical personnel must make technical explanations to the construction personnel. The contents of the explanations are mainly the construction methods, quality assurance measures and quality standards. Avoiding the influence of weather and environment on construction is conducive to construction quality control. The following main aspects should be paid attention to during the installation process.

1. Cutting Processing.

We should control the cutting length of the pipe, the straightness of the cut, the cleaning of the flash burr and the processing of the groove. The ultimate goal of the quality control of the blanking process is to ensure the welding quality and installation size.

2. Marking

Each welded joint of prefabricated pipes must be marked, especially alloy steel and special material pipes. Indicate the welding date, welder number, and welding port number. Mark the pipe number of each pipe section according to the single-line drawing. The pre-fabricated pipe section must close the end nozzle.

3. Welding

Welding quality control is the most important control link in process pipeline construction, requiring welders to strictly follow welding instructions.

4. Installation

On-site installation of process pipelines is a difficult point of quality control. It is restricted by on-site installation conditions and environmental factors, and appropriate quality assurance measures should be taken when necessary.

Construction Inspection

To a certain extent, the quality of the project must be measured by inspection. Non-destructive testing, pressure test, and purge are necessary components for the installation of process pipelines, which is the inspection of construction quality. This requires that there must be a certain planning arrangement, strictly in accordance with the requirements of the implementation.

1. Non-destructive Testing

Non-destructive testing comparison must be carried out in strict accordance with the requirements of the specification. Welding ports of each pipeline of each welder should be sampled. If unqualified welding ports are found, they must be repaired and double-checked until they are qualified. After heat treatment of alloy steel pipes, the hardness should also be measured.

2. Pressure Test

Except for painting and heat insulation, the pipeline installation works of the pressure test range have been completed in accordance with the design drawings, and the installation quality conforms to the relevant regulations. The pipeline to be tested and the irrelevant system have been separated by blind plates, and the safety valves, bursting plates and instrument components on the pipeline have been disassembled. Before pressure test, exhaust air when filling liquid. The test pressure should be slowly increased. After the test pressure is reached, stabilize the pressure for 10 minutes, then reduce the pressure to the design pressure, and stop the pressure for 30 minutes. If the pressure does not drop and there is no leakage, it is qualified. After the pressure test is completed, remove the blind plate in time and drain the liquid.

3. Purge

Before blowing, a blowing plan must be prepared. The specific blowing method should be determined according to the requirements for the use of the pipeline, the degree of contamination of the working medium and the inner surface of the pipeline. The maximum flow rate should be adopted for purging, and the flow velocity should not be less than 1.5m / s. Water rinsing should be carried out continuously, and the color and transparency of the discharge port should be consistent with the visual inspection of the permeation water.

The equipment, pipeline stainless-steel pipe fittings and valves are all crucial. But after the introduction, I think you have learned about the importance of quality control of pipeline.