China Public Recruitment Network

China Public Recruitment Network

It is necessary to set up a selection framework for riveting and welding units in the early stage of the project.

Many chemical designers easily overlook the qualification selection of riveting and welding units when writing project proposals or feasibility study reports. In fact, starting in 2023, the State Administration for Market Regulation has put forward more stringent requirements for pressure vessel design qualifications, especially regarding core equipment such as reactors, towers, and heat exchangers. If you have not pre-qualified riveting and welding units in the preliminary design stage, you will find that many units do not have the corresponding design permissions in the subsequent construction drawing stage, resulting in construction delays and cost overruns.

At the beginning of the project, I proposed that the review of the qualifications of the riveting and welding unit be included in the appendix corresponding to the feasibility study report. For example, in 2024, there was a petrochemical project in Zhejiang. During the preparation of the application report, three riveting and welding units with SAD grade pressure vessel design qualifications were predetermined. The entire project progressed very smoothly in the process equipment selection and calculation stages, and the owner was extremely satisfied.

How to judge the strength of the riveting and welding unit when selecting process equipment

When you are responsible for the selection of process equipment for production equipment, such as calculating the specifications of reactors, towers, and heat exchangers, the situation is that the technical capabilities of the riveting and welding unit directly determine whether the equipment can meet the standards. To have a reliable riveting and welding unit, you must not only have pressure vessel design qualifications, but also have actual manufacturing experience in similar projects. In 2025, for a chemical project in Shandong, when selecting a tower with a diameter of 3 meters, it was discovered that although a riveting and welding unit had complete qualifications, it had never manufactured such large equipment and was eventually excluded.

Having process design capabilities is also a very critical performance for riveting and welding units. They need to have the ability to understand the process flow diagrams and piping and instrumentation flow diagrams you provide, so that they can give common sense manufacturing suggestions based on the equipment layout diagram. If you notice that the other party cannot even clearly understand the key control points in the PID diagram, then you need to be vigilant. It is very likely that such a unit will frequently rework during the subsequent construction process.

The selection of safety valves and special pipe fittings exposes the professionalism of the riveting and welding unit

The selection and calculation of special pipe fittings such as safety valves, bursting discs, and flow-limiting orifice plates are often a touchstone to test the professionalism of riveting and welding units. A qualified riveting and welding unit can accurately calculate the discharge area of ​​the safety valve and the bursting pressure of the bursting disc based on the process parameters you provide. During a certain project in Jiangsu in 2024, the riveting and welding unit ignored the two-phase flow characteristics of the medium when calculating the safety valve, which resulted in an error in model selection. Fortunately, the designer discovered it when reviewing the procurement data sheet and avoided major safety hazards.

At the same time, the riveting and welding unit's handling of auxiliary pipe fittings such as water traps and small silencers can also reflect its relevant experience and sense of responsibility. Excellent units will proactively check the medium temperature, pressure and flow rate with you instead of directly copying the parameter table. If the other party just fills in the form mechanically without any technical communication, then you have to be more careful.

The coordination of riveting and welding units is very important when docking under design conditions.

When various majors provide design conditions, whether the riveting and welding unit can actively cooperate can directly determine the progress of the design. For example, when providing equipment layout drawings, the riveting and welding unit must feedback based on its own manufacturing capabilities whether the location of the equipment connection is reasonable and whether it is convenient for welding and inspection. In a certain project in Guangdong in 2023, the riveting and welding unit promptly gave suggestions for adjusting the takeover position, thus avoiding the need for later on-site cutting and modification, and saving approximately 150,000 yuan in costs.

The riveting and welding unit needs to coordinate with your process, piping, structure and other majors. If they can take the initiative to make suggestions about reserved holes for equipment foundations after receiving the utility system diagram, it shows that this unit has rich experience and a strong sense of service. On the contrary, if the other party only passively accepts the conditions and never actively provides feedback, then information gaps will easily occur during the project execution.

Riveting Unit Performance in Owner Services and Review Meetings

During the service stage for Party A, the performance of the riveting and welding unit is directly related to the owner's trust in you. For example, during the preliminary consultation of the project, an excellent riveting and welding unit will work with you to explain the equipment manufacturing process and inspection standards to the owner. In a project in Hunan in 2025, the riveting and welding unit faced the problem of welding process qualification raised by experts at the review meeting. It produced complete experimental data on the spot, which made the owner and the competent authorities look at it with admiration.

When participating in various review meetings organized by the construction unit or the competent department, the technical person in charge of the riveting and welding unit may wish to be present as much as possible. For these matters, they must be able to clearly and clearly answer questions about material selection, non-destructive testing proportions, heat treatment processes, etc. If there is a riveting and welding unit that hesitates during the review meeting, or if the representative sent cannot even understand the basic technical parameters, then their qualifications are probably just for show.

Completion acceptance and later cooperation are the final touchstone

Regarding the disclosure work and acceptance work in the later stage of the project, this is actually the final hurdle to determine whether the riveting and welding unit is reliable. For example, when the equipment arrives for acceptance, you have to check whether the design parameters on the product nameplate are consistent with your process equipment list, and check whether the appearance of the weld and the factory information are complete and appropriate. In a project in Henan in 2024, given that the riveting and welding unit proactively provided a complete set of welding process assessment reports and non-destructive testing records during the acceptance, the entire acceptance process only took three days.

After the project is put into production, it is also very important whether the riveting and welding unit is willing or unwilling to cooperate in dealing with the remaining problems. For example, when the equipment leaks or vibrates abnormally during operation, an excellent unit will send technicians to the site and help analyze the reasons. If the other party disappears without a trace after the acceptance inspection is completed, then other matters assigned by your leader may become a mess that is difficult to clean up.

When you choose a pressure vessel riveting and welding unit, which ability is most important to you? Welcome to share your experience in the comment area, like and bookmark this article to prevent mistakes next time.