The Third-Party Inspection for Valve article provides a sample valve inspection and testing procedure in the manufacturing shop. It is particularly suitable for inspecting gates, Globe, Ball, and Check Valves. This article should be reviewed with valve inspection and test plan articles. 

This content guides you through all necessary stages in producing the industrial valves, including the inspection of manufacturing material, casting, fabrication, dimensional inspection, NDE, final inspection, preservation, packing, and dispatch to the site.

You need to consider this: this article is written for a typical valve and might not be detailed for special cases.

All valve inspection and testing are 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 generally be individually witnessed on a test. However, with very large or special valves, such inspection may be extended to detailed component inspection of significant components. 

Such detailed inspection will always apply to valves intended for high-pressure steam, cryogenic, nuclear, or other critical services 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 are:

  • Design code
  • Purchase order specification
  • Purchaser’s standards
  • Approved drawings

and the applicable codes and standards are:

  • API 598
  • API 6D
  • API 594
  • ASME / ANSI B16.5
  • API 600, 602, 603, 604

The applicable codes and standards may be based on other international standards. This content is general and can be helpful even if the design code differs from the API Code.

Required Documents for Third Party Inspector Review:

The list of documents is typically agreed upon in the Pre-Inspection meeting, which is held several weeks before the actual commencement of the inspection work.

The parties participating 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.

This is the list of documents that are typically agreed upon to be presented to the inspector:

  • Valve Purchase Order or Contract
  • Valve Manufacturer Quality Control Plan
  • Valve Inspection and Test plan
  • Valve Data Sheet
  • Valve Approved Drawings
  • Valve Material Test Reports
  • Valve Welding Specification Procedures (WPS) and Procedure Qualification Records (PQR)
  • Valve Welders Qualifications Reports
  • Valve NDE Procedures ( Dye Penetration, Magnetic Particle, Radiographic, Ultrasonic, PMI Testing, etc. )
  • Valve NDE Personnel Qualifications Reports
  • Valve Heat Treatment Procedure
  • Valve Calibration Certificates for Test Equipment
  • Valve Hydrostatic Testing (shell) Procedure, Closure Testing Procedure, Backseat Testing Procedure, and Water Quality Document
  • Valve Preparation and Painting Procedure
  • Valve Preservation, Packing, and Shipping Procedure
  • Valve Packing List

Third-Party Inspection for Valve – Material Inspection

The first actual inspection work in the valve is the materials inspection. The original or authenticated copies of mill certificates of material usually 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:

  • Certificate No.
  • Heat or cast No.
  • Chemical composition.
  • Mechanical properties
  • Heat-treated condition.
  • NDE applied and results.
  • Surface finish

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 other components.

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 a specification must also be controlled.

When a third-party inspector carries out the material inspection and then provides the inspection report (IR), the report contains the following items:

  • Confirmation of satisfactory document review
  • Record of the endorsement of certification reviewed/witnessed
  • Record of all non-conformities
  • Record of any tests witnessed and the result

Third-Party Inspection for Valve – Welding Inspection

When the valve material inspection is carried out, the results are satisfactory, or non-conformities are closed by remedial action, 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 on the inspection budget, which purchasers assign for inspection. Much more inspection will have a much higher cost and less risk; conversely, less inspection will have less cost but more risks.

The third-party inspector performs a visual and dimensional check to ensure compliance with WPS and specifications. Where specified, weld bevels need to be examined by MT or PT after grinding/machining.

Edges and weld bevels must 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 to report severe or excessive defects.

The following items are considered when a third-party inspector inspects the valve welding:

  • Cleanliness and fit-up accuracy of preps.
  • The roundness of form of components.
  • Application of preheating.
  • Welding is in progress.
  • Cleaning of welds.
  • Completion of test coupons (where specified)
  • NDE. Results shall meet specifications or code requirements.
  • Hardness tests – when specified in the contract
  • Impact tests- when defined in the contract

Third-Party Inspection for Valve – Post Weld Heat Treatment

A third-party inspector carries out a dimensional check and PWHT control as specified. When PWHT has been completed, portable hardness measurement may be used to establish the hardness of the material, heat-affected zone, or welds, as specified.

Third-Party Inspection for Valve – Visual and Dimensional Checking

A third-party inspector controls the following points:

  • First, verify that the model, features, and components comply with the applicable purchase order description, valve specification, and drawings.
  • To verify that the dimensions of valves, flanges, flange drilling, bore, stem, threading, wall thickness, and any other sizes, as applicable, comply with the requirements of the specification and others.
  • Witnessing required pressure tests.
  • Witnessing functional test of the actuator on the valve when actuators are specified.
  • Radiographic examination and other NDE per the applicable references noted above.

Third-Party Inspection for Valve – Low-Pressure Air Test

When required by the contract or purchase order, the third-party inspector witnesses low-pressure air test and pays attention to the following points:

  • Specialized testing of seats, the seals, by-passes, etc., may be required by purchase order.
  • A minimum of 2 gauges with correct working ranges are used. The calibration of the gauges needs to be checked.

Third-Party Inspection for Valve – Hydrostatic Testing

The third-party inspector checks all previous items that authorized bodies and witness hydrostatic test have accepted and verify the following points:

  • Body tests, high-pressure closure tests, and back seat tests as detailed in applicable procedure and code specification.
  • Calibration status and correct working ranges of gauges. A minimum of 2 pressure gauges are attached to an item under test.
  • Adequate provision for venting high points and draining the test medium is provided.
  • Test pressure is applied as directed by procedure or code until test limiting pressure is reached. During the hold period, a systematic check for leaks is conducted.
  • Test pressures and metal and water temperatures are recorded.
  • Water quality is as specified.

These tests usually are on “Hold Point” or “Witness Point.”

Third-Party Inspection for Valve – Post Hydrostatic Testing

  • After depressurization, valve components are drained and dried to meet specified requirements.
  • Inspection authority stamps are carried out in an approved area, as the client/code requires.
  • Stamps used need to be low-stress type.
  • The application of desiccant/preservative needs to be directed to the client’s specification.

Third-Party Inspection for Valve – Final Inspection

A third-party inspector must check all valves for cleanliness and dryness. In addition, 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.

Third-Party Inspection for Valve – Name Plate Checking

The third-party inspector checks the content per the approved drawings and specifications and ensures it is stamped per the code requirements.

Third-Party Inspection for Valve – Painting, and Coating

Surface preparation for painting is checked for the following points, according to specification by a third party inspector:

  • Solvent Cleaning and Chloride Test
  • Cleaning method (brush-off blast cleaning, commercial blast cleaning, near-white blast cleaning, etc.)
  • Surface Profile measurements
  • Freedom from weld spatter, blowholes, and other defects
  • Dry film thickness is checked according to specification

Surface conditions must be free from pinholes, run damage, and other discontinuity.

Third-Party Inspection for Valve – Spare Parts, Loose Items, and Accessories

Per the purchase order specification, spare parts, loose items, and accessories are checked visually for their dimensions, materials, workmanship, and quantity.

Test marks and tags are checked for correct identification.

Third-Party Inspection for Valve – Reporting:

After each visit, the third-party inspector provides an Inspection Visit Report (IVR) and a final report summarizing the activities carried out during the valve production per the contract requirements and circulated within the time limits specified in the contract.

The report is in the format required by the client and indicates the final acceptance or rejection of the valve.

Third-Party Inspection for Valve – Release Note:

When the contract or purchase order is required, a release note is issued by the third-party inspection agency and given to the manufacturer when the valves have been accepted.

Third-Party Inspection for Valve – Packing, Marking, and Shipping:

The third-party inspector checks the following points:

  • Cleanliness and dryness of components
  • Rust prevention for all machined surfaces
  • Protection for cover for all opening and protruding parts
  • Packing style and suitably for overseas transportation
  • Shipping marks and other markings

Third-Party Inspection for Valve – Final Book (Dossier)

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