The Third Party Inspection for Valve article provides you with a sample valve inspection and valve testing procedure in the manufacturing shop. It is particularly suitable for the inspection of Gate, Globe, Ball and Check Valves. This article should be reviewed in conjunction with valve inspection and valve inspection and test plan articles.
This content guides you through all necessary stages in the production of the industrial valves, including the inspection of manufacturing material, casting, fabrication, dimensional inspection, NDE, final inspection, preservation, packing, and dispatch to site.
You need to take this point into account: this article is written for a typical valve and might not be detailed for special cases.
All valve inspection and testing is done against the approved drawings, purchase order specifications, purchasers or company standards, and within the practices and rules of the country, state or province and any government decrees, laws, ordinance or regulation as may apply.
As a general guide, all valves over 8" NB will normally be individually witnessed on test. With very large or special valves, such inspection may be extended to detailed component inspection of major components.
Such detail inspection will
always apply to valves intended for high pressure steam, cryogenic, nuclear or
other critical service, and in such instances, will extend to valves smaller
than 8" NB.
The applicable codes and specifications for a valve that is under the construction process is:
and the applicable codes and standards are:
The applicable codes and standards may be based on other international standards. This content is general and can be useful even if the design code is different from the API Code.
The list of documents normally is agreed upon in the Pre-Inspection meeting, which is held several weeks before the actual commencement of the inspection work.
The parties that participate in this meeting are the manufacturer, purchaser and third party inspection agency representatives.
This is already explained in the Inspection and Test Plan for Valve article.
These are the list of documents that are normally agreed upon to be presented to the inspector:
The first actual inspection work in the valve is the materials inspection. The original or authenticated copies of mill certificates of material normally are available at the manufacturer's premises.
The third party inspector examines these certificates for compliance with specifications, and where appropriate, drawings.
The review includes checks on:
This covers body stem material, shell material, trim materials, gland materials, anti-friction materials, ball, wedge or flap materials, operating components, support material, well end, flanges and any other specified component.
Then the inspector witnesses the materials identification on the certificates against the materials marking. It is also necessary to check these with the valve drawing datasheet, material list and other specifications as appropriate.
Visual inspection for surface finish and probable defects is done and dimensional compliance with specification need to be controlled, as well.
When third party inspector carries out the material inspection, then provides the inspection visit report (IVR), the report contains the following items:
When the valve material inspection is carried out, and the results were satisfactory or non-conformities were closed by remedial action, then the valve manufacturer will start fabrication.
The third party inspector checks the following points on the valve based on the inspection and test plan (ITP), which has already been agreed upon between the purchaser and the valve manufacturer.
The inspection scope is determined in the ITP. Some purchasers prefer to have stringent controls and assign the TPI for more “hold or witness points” for inspection and test activities, and some others prefer less “hold or witness points” and assign the TPI much more work in the “review document.”
This depends in the inspection budget, which purchasers assign for inspection. Much more inspection will have a much larger cost and less risk, and conversely, less inspection will have less cost but more risks.
The third party inspector carries out visual and dimensional check to ensure compliance with WPS and specification. Where specified, weld bevels need to be examined by MT or PT after grinding/machining.
Edges and weld bevels need to be clean, dry and free from surface defects, laminations, cracks, voids, notches, etc.
These are causes for rejection unless suitable/satisfactory remedial action can be taken. Welding repairs to bevels are not permitted, without approval from the client. Inspectors need report excessive or serious defects.
Following items are taken into account when third party inspector making inspection on the valve welding:
Third party inspector carries out dimensional check and PWHT control as specified. When PWHT has been completed then portable hardness measurement may be used to establish hardness of material, heat affected zone or welds, as may be specified.
Third party inspector controls following points:
when required by the contract or purchase order, the third party inspector witnesses low pressure air test and pays attention to the following points:
The third party inspector checks all previous items have been accepted by authorised bodies and witness hydrostatic test and verify following points:
These test normally are on "Hold Point" or "Witness Point"
All valves need to be checked for cleanliness and dryness by third party inspector. Nozzle, outlets, flanged or butt welded, saddle, bracket locations and orientations against assembly drawings are controlled and operation of valve indicator and correct functioning also be checked.
The third party inspector checks the content in accordance with the approved drawings and specifications and make sure it is stamped in accordance with the code requirements.
Surface preparation for painting is checked for the following points, according to specification by third party inspector:
Surface condition need to be free from pin-holes, runs damage and other discontinuity.
Spare parts, loose items and accessories are checked visually for their dimensions, materials, workmanship and quantity, according to the purchase order specification.
Test marks and tags are checked for correct identification.
TThe third party inspector provides an Inspection Visit Report (IVR) after each visit, as well as a final report summarizing the activities carried out during the valve production in accordance with the contract requirements and circulated within the time limits specified in the contract.
The report is in the format required by the client and clearly indicates final acceptance or rejection of the valve.
When required by the contract or purchase order, a release note is issued by the third party inspection agency and given to the manufacturer when the valves have been accepted.
The following points are checked by the third party inspector:
The following final documents are reviewed and signed off by the third party inspector:
As built drawings, Manufacturer's data reports, Material certificate or certified mill test reports for all pressure parts, Material list or map, Welder record for each weld, Heat treatment records (Temperature-time record chart during PWHT), Dimensional record, NDE records, Pneumatic test record, Hydrostatic test record, Hardness test record, Final assembly checks, Marking inspection report, Packing list, Spare parts list
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