Is it necessary to sign a subcontract for the head cover work?
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This post was last edited by zjq1962 on 2018-6-28 at 14:52. As the title suggests, in today’s world, it’s unlikely that there is only one company responsible for manufacturing pressure vessels or for handling the work related to vessel heads; is it necessary to sign a subcontracting agreement? If most of the physical and chemical tests are carried out by the own organization, with only a small number of those that exceed its capabilities being done by specialized testing institutions, is it necessary to sign an agreement in such a case? Are there clear regulations?
It should be specified in the procurement (supply) contract what inspections and tests Party B needs to carry out and what certifications it needs to provide.
The last edit of this post was made by Save for future reference on 2018-6-28 at 15:13. The main aspects that pressure vessel manufacturing units need to consider for qualified supplier evaluation include: 1) major components such as heads and forgings, 2) physical and chemical properties, 3) heat treatment. Whenever manufacturing or testing is carried out externally, it is necessary to conduct an assessment of qualified suppliers (the purpose of this assessment is to determine whether the supplier possesses the appropriate qualifications), and a list of qualified suppliers should be established. The subcontract agreement is signed after being designated as a qualified supplier. Only then can components and manufacturing processes that the company cannot handle itself be outsourced to third parties.
Do qualified suppliers also include material suppliers? All suppliers need to be evaluated on an annual basis.
Plate and pipe materials do not require a qualified supplier evaluation. A subcontract agreement can specify a duration, but the subcontractor is evaluated annually. Because the supplier’s qualifications may expire or there may be other issues that prevent them from meeting the requirements of a qualified supplier.
This post was last edited by Zhizhi Ming on 2018-6-29 at 08:33. Material suppliers (including contractors and third-party service providers) also need to undergo a qualified supplier assessment; the details of this assessment can be simplified to some extent, but all basic information about the company must be reviewed (such as business license, certification of quality management systems, financial reports, etc.). The so-called assessment of qualified suppliers involves evaluating them effectively to ensure that their quality assurance systems meet the company’s requirements, that the raw materials they supply satisfy the company’s quality standards, and ultimately to guarantee that these suppliers have the capability to provide a continuous, stable, and cost-effective supply of materials to meet the company’s needs.
Agree with the second floor’s opinion; an agreement needs to be signed in all cases!
The last edit to this post was made by zjq1962 on 2018-6-29 at 10:08. Pressure vessel manufacturing units that outsource tasks such as non-destructive testing, heat treatment, physical and chemical testing, and cylinder rolling must enter into subcontracting agreements with those subcontractors, and such agreements must be filed with the certification authority. For the subcontracting of end caps, if the welding and non-destructive testing of these end caps are carried out by the same company, then the company responsible for shaping the end caps only needs to have sufficient pressing capabilities; no license is required at present, nor is it necessary to issue a supervision certificate ； If the splicing is carried out by head forming units, a license for manufacturing special equipment is required, and a inspection certificate must be issued upon the delivery of the heads. There is no basis for determining whether to enter into an agreement, but first it is necessary to assess the capabilities and performance of the end-cap manufacturing plants; those that meet the standards are included in the list of qualified suppliers, with follow-up evaluations conducted annually. Pressure vessel manufacturers shall evaluate the suppliers of materials used for pressure vessels, carrying out such evaluations annually; qualified suppliers are included in a list of approved suppliers, which is a requirement of the quality assurance system for pressure vessel manufacturing.
I’ve learned it; standards and regulations are being updated quite rapidly these days, so it’s necessary to keep learning*
Alas, over the years, manufacturing pressure vessels has required specific qualifications as well as supervision and inspection. This reform eliminates those requirements for manufacturing pressure vessels, following the example of ASME*, but it has left vessel manufacturers confused. **Which department will step forward to explain this? ;P