Third Party Inspection for Valve - Procedure

18 Aug.,2025

 

Third Party Inspection for Valve - Procedure

Third Party Inspection for Valve - Procedure

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. 

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The I4I Academy's API 570 Inspector training course explains the different valve types with inspection and testing requirements. It is also covered in the API Source Inspection Fixed Equipment Course.

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:

  • 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 useful even if the design code is different from the API Code.

Required Documents for Third Party Inspector Review:

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:

  • Valve Purchase Order or Contract
  • Valve Manufacture 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 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:

  • 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 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:

  • 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, 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:

  • Cleanliness and fit up accuracy of preps.
  • Roundness of form of components.
  • Application of preheat.
  • Welding 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 specified in the contract

Third Party Inspection for Valve - Post Weld Heat Treatment

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 Inspection for Valve - Visual and Dimensional Checking

Third party inspector controls following points:

  • To verify that the model and various features and components comply with the purchase order description and valve specification and drawings as applicable.
  • To verify that the dimensions of valves, flanges, flange drilling, bore, stem, threading, wall thickness and any other dimensions, as applicable, comply with the requirements of the specification and other.
  • Witnessing required pressure tests.
  • Witnessing functional test of actuator on valve, when actuators are specified.
  • Radiographic examination and other NDE in accordance with 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 have been accepted by authorised bodies and witness hydrostatic test and verify following points:

  • Body tests, high pressure closure tests, 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 item under test.
  • Adequate provision for venting of high points and draining of the test medium are provided.
  • Test pressure is applied as directed by procedure or code until test limiting pressure is reached. During hold period, a methodical check for leaks is conducted.
  • Test pressures, metal and water temperatures are recorded.
  • Water quality is as specified.

These test normally are on "Hold Point" or "Witness Point"

Third Party Inspection for Valve – Post Hydrostatic Testing

  • After depressurisation, valve components are drained and dried to meet specified requirements.
  • Stamping of Inspection authority stamps, are carried out in approved area, as required by client/code.
  • Stamps used need to be low stress type.
  • Application of desiccant/preservative need to be as directed in client's specification.

Third Party Inspection for Valve – Final Inspection

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.

Third Party Inspection for Valve - Name Plate Checking

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.

Third Party Inspection for Valve - Painting and Coating

Surface preparation for painting is checked for the following points, according to specification by 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, blow-holes and other defects
  • Dry film thickness is checked according to specification

Surface condition need to be free from pin-holes, runs damage and other discontinuity.

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

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.

If you are looking for more details, kindly visit gate valve tester.

Third Party Inspection for Valve - Reporting:

The 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.

Third Party Inspection for Valve - Release Note:

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.

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

The following points are checked by the third party inspector:

  • 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

FAQs | U.S. Pipe Valve & Hydrant, LLC

Gate Valves

In addition to the year of manufacture, resilient wedge gate valves contain a six digit Julien number that represents the date and shift the bonnet was created. For example, if the code reads , then 07 is the month, 10 is the day, 4 is the last digit of the year, and 3 is the shift.

The valve may be larger than shown on the plans. Continue to operate based on the next size valve. Alternatively, the valve may have a bevel or spur gear to assist during operation. Check the plans to see if it a gear was installed on the valve. Excessive torque may have been applied to the wrench nut at some point and damaged the stem or stem nut. If this is the case, expose the valve and inspect the stem and stem nut. Replace if necessary.

First, be sure the valve is completely closed by counting for a proper number of turns (based on the valve size). Verify the required closing torque by comparing to the manufactures published information. The disc may have been closed against debris. If this is the case, create flow through the valve (open a nearby downstream hydrant) and exercise the valve to loosen/remove the debris. Also, air may be trapped in the line. Flush the line to remove the trapped air. Add an air release valve if necessary.

Tuberculation or debris may have built up in the seat area, particularly with double disc gate valves. To correct, create flow through the valve (open a nearby downstream hydrant) and then exercise the valve to loosen/remove the debris.

The valve box may be interfering with the wrench nut socket/tool. Look down the valve box to see if it is too close to the wrench nut. Reposition if necessary. Alternatively, the stuffing box bolts and nuts may have been tightened down unevenly during assembly. If that is the case, loosen and retighten stuffing box bolts and nuts evenly. In addition, debris or corrosion may have built up between the stem and stuffing box due to lack of operation or gritty backfill. This requires removal of the stuffing box (stem if needed) and cleaning and/or replacement of the stem and stuffing box. Lastly, debris could have wedged under the disc. Expose the valve. Isolate the valve from flow and relieve pressure. Remove the bonnet. Clean out the debris.

Verify the bolts and nuts are torqued according to the operating manual. The bonnet gasket O-ring may be damaged or pinched. Isolate the valve from flow and relieve pressure. Remove the bonnet. Replace the gasket. Alternatively, the body or bonnet flange may be cracked or broken. Inspect the valve body and bonnet flanges. Replace damaged items.

It is possible that the stuffing box packing is not sealing properly. If this is the case, remove the stuffing box and replace the stem O-rings and the stuffing box packing. Note that U.S. Pipe Valve & Hydrant started using O-rings in .

The AWWA operating formula for opening/closing a gate valve is 3 times the nominal valve size plus 2 or 3 turns of the operating nut. For example, a 6-inch gate valve would require 6 x 3 = 18 turns plus 2 or 3 turns, for a total of 20 to 21 turns.

Contact our customer service for further information. (This will be very limited, which may be only “O” rings.)

No, parts are no longer available for this product.

Training

Contact your local U.S. Pipe Valve & Hydrant sales representative.

Mueller Co. offers two (2) different types of classes: (1) Mobile Training Van; and (2) Annual Training School. The Mobile Training Van takes our school on the road in the Spring, Summer and Fall with stops at U.S. Pipe Valve & Hydrant Stocking Distributor locations. The van covers a different area of the continental US each year. There is no charge to attend one of these sessions. Contact your local U.S. Pipe Valve & Hydrant Authorized Distributor to inquire about classes in your area, and to register your interest in attending. Our Annual Training School is conducted every winter at the Mueller Technology Center in Chattanooga, TN. This 3-day class is designed specifically for distributor personnel. To assure each participant will receive proper hands-on product experience, the class size is limited to 20 students.

Fire Hydrants

Yes, please contact our customer service representative at 800-423- for a complete listing. (Unless we want to have a diagram of the S on the website.)

Yes, please contact our customer service representative at 800-423- for a complete listing. (Unless we want to have the diagrams listing of parts we offer.)

Start with the first hydrant nearest where the new main connects into the system, and work toward the farthest hydrant. Open the first hydrant as fast as possible until fully open, and allow it to run for five minutes, then close it fully. Do this on successive hydrants until the entire system of pipes has been flushed.

The first two numbers in the code are the number of threads per inch and the last three digits are the pitch diameter. For example, a thread gage is 6.0 threads per inch (TPI) with a 5.60" pitch diameter (PD).

For Sentinel® Fire Hydrants Only: Instead of using a standard MJ connection with an add-on bolted restraint system, which can leave several bolts out of reach underneath the pipe, use the Mueller® Aqua-Grip® system, which includes an MJ-type connection and pipe restraint without any bolts underneath the pipe. Plus, the Aqua-Grip systems involves far fewer bolts to tighten when it’s installed.

For Sentinel® Fire Hydrants Only: The Mueller® Vertical Aqua-Grip® Hydrant allows the use of any length of standard ductile iron pipe to be used to extend from the hydrant shoe directly down to the main’s level.

NFPA sets the guidelines which govern the spacing for private and recommended spacing for public water systems. Most engineers will follow the guidelines set forth by NFPA but with public systems they set their own rules and regulations. NFPA 1, Section 18.3.3.1 says the maximum spacing for residential lots 20,000 square feet or larger should be 1,000 ft.; 750 feet for residential lots of less than 20,000 square feet; and 500 feet for townhomes and apartments. For more information, please visit: http://my.firefighternation.com/forum/topics/fire-hydrant-spacing?q=forum/topics/fire-hydrant-spacing.

17-1/4 turns on all Sentinel hydrants.

This situation can occur if the hydrant has been left idle for many years without annual exercise, or if the main valve is brass and it is threaded directly into an iron mounting. U.S. Pipe Valve & Hydrant fire hydrants have brass-on-brass main valve mountings to help avoid corrosion that can occur with brass-on-iron. For a main valve assembly that cannot be loosened using a seat wrench, try pumping out all accumulated water, pour in one to two liters of a cola soft drink, and let it soak (overnight might be necessary).

U.S. Pipe Valve & Hydrant offers extension kits to increase bury depth for both M-94 and Sentinel hydrants. Contact customer service for kit numbers - specify change in bury depth needed. Shortening hydrant bury depth requires replacing the Lower Standpipe & Lower Rod.

Opening direction can be changed by replacing the Revolving Nut, Upper Rod and Bonnet.

Operating Nut size can be changed by simply replacing the Operating Nut with the required size. Generally hose and pumper cap nut match the operating nut so new caps may be required. Specify the thread gage and nut size when ordering.

Specify size of pumper nozzle and thread gauge and order the following: Nozzle Lock; Pumper Nozzle; Pumper Nozzle Gasket; Pumper Nozzle O-ring; Pumper Cap (Specify size and shape of operating nut.); Cap Chain w/Ring; Chain Hook(s)

Different coatings have been used over the years on USP hydrants. Since both M-94 and Sentinel hydrants have been top-coated with polyurethane epoxy. See the USP website for instruction on touch-up and repainting USP hydrants.

Many systems still specify the use of ground key valves in service lines, which are only rated to 100 psi. Testing new lists at 200 psi, even 150 psi push these valves to their limit and sometimes leakage can cause a test failure. Using Mueller 300® Ball Valves, which are rated at 300 psi can help assure successful testing. Mueller® Oriseal® Valves are plug style valves with O-ring seals, and are rated at 175 psi, and offer an alternative. When using ground key valves, it is helpful to rotate or “cycle” the key to redistribute the grease when installing the valve. Never tamper with the nut on the bottom of the key, as in Mueller valves, this nut is factory tightened to a precise torque, and loosening it can change the valve’s pressure holding capability.

First, make sure the hydrant is well lubricated; lubricate as directed in the operations manual. If lubrication isn’t the issue, it could be the hydrant has been over tightened and the stem bent. In this case, the stem will have to be replaced. If the hydrant is old or has not been exercised in sometime, corrosion or build up of deposits in the main valve could be a problem in which case, the main valve will have to be serviced. If it is an especially old hydrant, over fifty years old for instance, sometimes the best solution is to replace it.

The grease is designed to operate in both cold and warm climates. It is best to use USP grease. It is recommended that different greases not be mixed. Some greases are not compatible with others and can break down.

The rod coupling may be broken or the rod coupling pins were not installed or have failed.

Sentinel & M94 Maintenance Manuals &/or Videos

14 turns on all M-94 hydrants.

32: Lower Stem, 33: Lower Barrel, 29: Barrel Coupling Seal, A-38: Base O-Ring Seal

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