API 11D1 vs ISO 14310 - what a V0 rating actually certifies

A V0 rating under API 11D1 or ISO 14310 certifies that one packer or bridge plug design, at the size it was tested in, held gas with zero bubbles through axial loads and a temperature cycle between its rated limits. It is a record of a design test, not a certificate for a company or for each tool. API Spec 11D1, fourth edition, now carries V0 in three forms (V0, V0-R and V0-HR), where ISO 14310, second edition, has one.

API's own Addendum 1 to API Spec 11D1, fourth edition, also replaced the legacy V0-H and V3-H validation grades with V0-HR and V3-HR.

You may have a datasheet, a tender clause or a supplier's letter in front of you that says V0. This page sets out the meaning of that rating: what it promises, what it leaves out, which grade your well needs, and how to check the claim before you sign. The question reviewers ask most, how you know the packer sealed once it is in the hole, gets a full answer in the check further down.

The page compares the two documents from their published scopes and API's own addendum, and it rates no company and no product. A few rules carry most of the weight, and they come first.

Key takeaways

• V0 is the gas-tight design validation grade, tested with gas, axial loads and temperature cycling and passed with zero bubbles; a lower grade number means a more severe test.
• A V0 rating belongs to one design at one size and envelope; API Spec 11D1 bars a casing ID larger than the test fixture, and scaling cannot raise it.
• API Spec 11D1 and ISO 14310 began as one text and now differ, so ask which edition a claim means and whether it is ISO 14310 V0, API legacy V0, V0-R or V0-HR.
• A validation grade is not a licence or a certificate: ISO issues none, and an API Monogram licence belongs to a facility and is checked on the API Composite List.
• The grade you need follows from your well conditions (gas, heat cycles, loads, HPHT); specify it in the RFQ and ask for the design validation record for the exact model and size.
• A V0 test shows the design can seal under test conditions, and the barrier test after setting shows that your tool sealed in your well.

What are API 11D1 and ISO 14310, and how are they related

API Spec 11D1 and ISO 14310 set the requirements for packers and bridge plugs used inside casing or tubing: API 11D1 from the American Petroleum Institute, ISO 14310 from the International Organization for Standardization. Both cover the functional and technical specification of that equipment: design, design verification and design validation, materials, documentation and data control, repair, shipment and storage. Both leave installation and maintenance outside their scope.

The two documents began as one text. API's early editions of API 11D1 adopted ISO 14310, and its second edition was a national adoption of the second edition of ISO 14310. Later API editions modified the ISO text instead of adopting it whole.

API Spec 11D1 is now in its fourth edition, amended by Addendum 1 and Errata 1. ISO 14310 is in its second edition, reviewed and confirmed as current by its committee, ISO/TC 67/SC 4. That edition is now under revision, and a third edition is in development under the title "Oil and gas industries including lower carbon energy, Downhole equipment, Packers and bridge plugs".

Neither document is a certificate. ISO publishes the standard and, in its own words, "does not perform certification or issue certificates". API publishes API Spec 11D1 and also runs a licensing programme, the API Monogram, under which a facility is licensed to mark the products it makes to the specification.

Because API kept revising its text while the second edition of ISO 14310 stayed current, the two now differ in places a purchase order has to name.

Where do API 11D1 and ISO 14310 differ today

API Spec 11D1, fourth edition, and ISO 14310, second edition, cover the same equipment but now differ in their validation grades, their treatment of high pressure and high temperature, and how a claim against them can be checked. The short answer to API 11D1 vs ISO 14310: the equipment is the same, and the grades are not. Specify the document and the edition on the purchase order as well as the grade.

The fixture-size and scaling rules set out further down are stated as API Spec 11D1 writes them; check the ISO 14310 text you buy for its own wording.

One thing the two documents still share is the grade ladder itself, which runs from V6 to V0.

What does each validation grade test, from V6 to V0

API 11D1 and ISO 14310 validation grades rank a packer or bridge plug design by the test it passed, from V6, a method the manufacturer defines, to V0, the gas-tight grade. A lower number means a more severe test. A V0 packer is one whose design passed the bottom row of the table below.

Grade definitions as published for ISO 14310.

In API Spec 11D1, fourth edition, the -R grades (V6-R to V0-R) follow the same pattern under the fourth edition's own requirements. V3-HR and V0-HR add the HPHT validation of Annex B.

A design validated to a higher grade counts only for the lower grades its test includes. V2, a gas test without temperature cycling, does not cover V3, a liquid test with it; the API Spec 11D1 licensing form says so directly. In the hierarchy table (Table 4) of Addendum 1, V0-HR covers V3-HR, V0-R and the legacy grades V0 to V6.

Every test in the ladder starts the same way. The tool is set in the largest-ID test fixture it is rated for, at its maximum rated temperature, with the minimum setting force the manufacturer specifies. Each hold period lasts at least 15 minutes.

The V0 row is short in a table; on the test rig it runs as a sequence of steps.

What does a V0 test involve, and who runs it

A V0 validation test takes one packer or bridge plug of the design being validated and proves it holds gas with zero bubbles at its rated pressure, from above and below, under axial load and across its rated temperature range. Both documents require two separate steps for a design. Design verification checks it on paper, through calculations, design reviews and comparison with proven designs; design validation tests a physical example on a rig.

A V0 test runs in this order:

1. Set the tool in the test fixture with the maximum ID it will be rated for, at its maximum rated temperature, using the manufacturer's minimum setting force.
2. Apply gas, air or nitrogen, at the rated differential pressure from above, then make a pressure reversal and apply it from below.
3. Apply tension and compression within the performance envelope while the pressure holds.
4. Cool to the minimum rated temperature and test again.
5. Return to the maximum rated temperature and test again, which completes the temperature cycle.
6. Hold each test for at least 15 minutes, with zero bubbles in every hold period.
7. For a retrievable tool, release it and remove it by its own retrieval procedure.

The test produces a design validation record, the test report, and the performance envelope, which plots the pressure the design holds against the axial load it carries.

The manufacturer, as the supplier of the design, runs the validation. Neither document, as publicly described, requires an independent witness. A purchaser who wants one writes it into the enquiry, and the text you purchase governs if it says otherwise. A purchaser can also add test conditions beyond the standard fixture, such as qualification in as-rolled casing instead of a machined fixture.

A record showing all seven steps passed still leaves one question: what, exactly, has the test proven?

What does a V0 rating actually certify, and what does it not

A V0 rating certifies one thing: that a design was tested at one size and within one envelope and held gas with zero bubbles under the V0 conditions. Everything else a buyer needs has to come from somewhere else, and the seven limits below say where.

1. A V0 rating does not certify each tool you receive. The grade is earned once by a design at a size. Each production tool is covered instead by the quality level on the order and its own plant test record, issued against its serial number.
2. The rated size stops at the test fixture. Under API Spec 11D1, a design cannot be rated for casing or tubing whose maximum ID is larger than the test fixture's ID. The fixture's nominal ID may vary by no more than 0.76 mm (0.030 in), as clause 6.5.2 of API Spec 11D1, fourth edition, Addendum 1, sets out.
3. The performance envelope is fixed by the test. A validated design holds only the pressure, temperature range, temperature-cycle range and loads it was tested to, and scaling it to another size cannot raise any of them, or the grade.
4. Your well fluids are a separate question. The test media are water or hydraulic oil and air or nitrogen. How the elastomer element and the metallurgy stand up to H2S, CO2 and brines is an environmental compatibility selection the purchaser specifies.
5. Installation sits outside both documents. A passed test shows the design can seal, and the barrier test after setting shows your tool did.
6. The grade is not a licence. ISO issues no certificates, and an API Monogram licence belongs to a facility, for the products and highest grade on that licence, not to a datasheet.
7. The label has to match the test. ISO 14310 V0, API legacy V0 in Annex A, V0-R and V0-HR are four labels with different test requirements. A design validated to an earlier edition may need further validation to claim a fourth-edition grade.

A V0 claim should say who stands behind it: the manufacturer's own validation record, a named independent witness, or an API Monogram licence that covers the grade. A claim that reads "ISO 14310 certified" names no issuer, for the reason given in limit 6.

The same letters also turn up in other specifications, where V0 means a different test on a different tool.

Which equipment do API 11D1 and ISO 14310 cover, and which do they not

API 11D1 and ISO 14310 cover packers and bridge plugs, permanent, retrievable or repositionable, used inside casing or tubing. Swellable, inflatable and expandable packers are covered instead by API Spec 19OH, Openhole Isolation Equipment, which sets its own design validation requirements.

Outside the scope of both documents:

• Openhole isolation equipment, including the swellable packer, the inflatable packer, the expandable packer and other openhole packers, which API Spec 19OH governs.
• Liner hanger equipment, which falls under API 19LH and which API Spec 11D1 names as outside its scope.
• Completion accessories such as sleeves, which fall under ISO 14998 and API Spec 19AC. Both carry their own grades, including a V0, so a V0 on such a tool is not an API 11D1 or ISO 14310 V0.
• Installation and maintenance of any of this equipment.

API Spec 11D1 states the boundary in its own scope: products covered by other API specifications, such as API 19OH or API 19LH, are not covered by it.

If a datasheet shows a grade on a swellable packer, ask which document the grade refers to. The answer should be API Spec 19OH or the manufacturer's own test. The supplier checks further down this page then apply to that record as to any other.

For a packer or bridge plug inside casing or tubing, the next decision is which grade to specify.

Which validation grade should you specify for your well

The validation grade to specify is the one whose test includes every condition your well will put on the packer or bridge plug. That means gas if the seal must hold gas, axial loads if the string will move or pull, temperature cycling if the well heats and cools, and an -HR grade above 15,000 psi or 350°F. Read your well conditions down the left column of the table, and carry the grade into the RFQ and the functional specification.

Specify the quality level separately from the grade, and state the well fluids separately too, because the validation grade decides neither.

Your operator's well barrier policy or the tender text overrides this table wherever it names a grade. A public tender for bridge plugs, for example, can write the document and the grade straight into its specification line.

A higher grade, or an -HR grade, means a heavier validation programme for the design. Ask at RFQ whether the design at your size is already validated to the grade you specify.

When the grade and the well do not match, the gap shows up downhole, not on the approval form.

What goes wrong downhole when the grade does not match the well

A packer or bridge plug validated to the wrong grade usually fails in one of five ways, each traceable to a condition its test did not include.

• A liquid-tested grade, V5 to V3, used in gas service lets gas find leak paths a liquid test never revealed. Annulus pressure can then build above the tool.
• A grade without temperature cycling, in a well that heats and cools, can hold at one temperature and then lose seal contact. That happens as the well cools after a shut-in or heats again on start-up.
• An axial load outside the performance envelope can unseat the tool or move its slips. A retrievable tool may then fail to release when the time comes to pull it.
• A casing ID larger than the validated test fixture leaves the element more gap to close than it was tested to close, and gives the slips less to grip. That is why API Spec 11D1 does not let the rating stretch past the fixture.
• An elastomer element not suited to the well fluids, H2S and CO2 among them, hardens, swells or extrudes, and once extrusion starts the seal leaks.

One practitioner put the cost of any of these plainly: "If this tool fails downhole it costs me days of rig time, a fishing job, maybe a sidetrack."

Most of these failures can be caught at the approval stage, by checking the claim before the tool is ordered.

How do you check a V0 claim before you approve a supplier

V0 claim is checked against the design validation record behind it. You match the document, the grade, the size and the test conditions to the tool and the well you are buying for. The ten steps below take you from the claim to that record, and then to the proof that the tool sealed once it is in the hole.

1. Ask which document, edition and grade the claim means: ISO 14310 second edition V0, API Spec 11D1 legacy V0 in Annex A, V0-R or V0-HR. A bare "V0" is not a specification.
2. Ask for the design validation record, the test report, for the exact model and size quoted. A brochure line is a claim, and the record is the evidence behind it.
3. Read the record for the test fixture ID, the casing size and weight range claimed, and the test media. Check the rated pressure and its direction, the upper and lower temperatures of the temperature cycle, and the axial loads. Then read each hold period and its bubble result, the retrieval result for a retrievable tool, who ran the test, and whether an independent witness was present. A record missing any of these leaves part of the claim unproven.
4. Compare the largest inside diameter in your casing weight range with the test fixture ID. Under API Spec 11D1, clause 6.5.2, the rating cannot stretch past the fixture.
5. Ask whether your size was tested or reached by scaling from another size. Under clause 6.8.2, scaling cannot raise the pressure, temperature, load, rated ID or grade of the validated design.
6. Check that the performance envelope covers your load cases: the pressure you will hold together with the tension or compression you will apply. A pressure figure read without the load beside it can sit outside the envelope you need.
7. Check the element compound and the metallurgy against your well fluids as a separate line. The grade test uses water or hydraulic oil and air or nitrogen, so it does not cover them.
8. Check the quality level on the order, and the plant test record for each tool against its serial number. The grade covers the design, and these cover the tool.
9. If the claim says "API 11D1 monogrammed" or carries an API licence reference, look up the facility on the API Composite List at mycerts.api.org. Read its Status, and check that the products listed match what you are buying. Only Active means a licence in force, and a register entry shows a facility's licence, not that a particular tool was made under it.
10. After the tool is set, rely on the barrier test, not the grade: the operator's pressure test after setting, and an inflow test where the barrier policy calls for one. These verify that this tool sealed in the hole in this well. For a swellable packer, the same holds once it has swelled.

Treat any of these as a red flag:

• "V0" with no document, edition or suffix.
• "ISO 14310 certified" with no issuer.
• A grade with no size or casing range attached.
• A test record with no fixture ID or no test temperatures.
• Leak figures that match no published grade definition.
• A V0 on a swellable packer that cites ISO 14310.
• A licence reference that cannot be found on the API Composite List.

Apply the same ten checks to every supplier you are qualifying, the publisher of this page included. The same care applies to this page, which has limits of its own.

What does this page not cover

This page explains what API 11D1 and ISO 14310 validation grades mean and how to check a claim; it does not do the five things below.

• No product and no company is rated or named.
• Clause text is not reproduced. The edition you buy from API or ISO governs, and the detailed test criteria of the fourth edition sit in clause 6.5 of API Spec 11D1.
• The API Monogram licensing programme, and how to read a licence number, are separate subjects not explained here.
• This page does not cover openhole isolation equipment or completion accessories beyond naming the documents that govern them: API Spec 19OH, ISO 14998 and API Spec 19AC.
• The grade allowances quoted are the published public definitions of the grades, and that limit matters: a reviewer confirming a contract requirement reads the purchased text.

Installation, setting, running and retrieval follow the manufacturer's current running procedure for the tool and the operator's programme, not this page.

The same questions this page asks of any supplier apply to the company that publishes it.

How does Maximus OIGA Private Limited answer these questions for a SpectraMax packer or bridge plug

Maximus OIGA Private Limited builds each SpectraMax packer and bridge plug to order at its plant at Manjusar and Savli GIDC, Vadodara. Its quotation states the pressure and temperature envelope for the exact tool quoted, with the test evidence behind it. Each tool is engineered to order against your purchase order rather than resold from stock.

Each SpectraMax tool is pressure and function tested at the plant as built, and its plant pressure and function test record is issued against that tool's serial number. That plant test record covers the tool you receive, while a validation grade is backed by the design validation record for the design. Ask for both, from this manufacturer as from any other.

The element compound is quoted per tool from the bottomhole temperature and the well fluids. The choice is made from Nitrile, HNBR, HSN, Viton and Aflas, which settles the fluid question at quotation, outside the grade.

Each order ships with a documentation pack: a dimensional drawing with gauge OD and bore, a material test report traceable to heat numbers, the element compound certificate, the plant pressure and function test record, and a certificate of conformity to the purchase order, with an inspection and test plan when your QA requires one.

Lead times run in bands by product class: 1 to 4 weeks, 4 to 12 weeks, and 8 to 16 weeks or more. The quotation states the lead-time band for your build.

To get a quotation you can check, specify the document, edition and grade your specification calls for, plus the quality level. Add your casing size and weight, setting depth, setting method, differential pressure and its direction, bottomhole temperature and well fluids. Then run the ten checks above on what comes back.

Reviewers still ask a handful of questions that fall between these sections, and the answers follow.

What else do reviewers ask about API 11D1, ISO 14310 and V0

What is the latest edition of API 11D1?

API Spec 11D1 is in its fourth edition, amended by Addendum 1 and Errata 1. API and authorised standards resellers sell the document, and the matching ISO document is ISO 14310, second edition, with a third edition in development.

Is a V3 packer enough, or do you need V0?

A V3 grade proves a liquid seal under axial loads across the rated temperature range. V3 does not test gas, so where the seal must hold gas the grade to specify is V1 or V0, and V0 where no gas leakage is acceptable.

Is Q1 in ISO 14310 the same as API Spec Q1?

Q1 in ISO 14310 is the most demanding of three quality-control grades for the product. API Spec Q1 is a different document: a quality management system specification for organisations that provide products to the petroleum and natural gas industry. One describes how a product is inspected; the other describes how a company runs its quality system.

Does a V0 rating mean the packer will not leak in your well?

A V0 rating means that the design showed zero bubbles during the test holds, at its tested size and conditions. Your well adds fluids, time, loads and an installation the test did not include, and the operator's barrier test after setting is what shows this tool sealed.

Does a V0 rating apply to a swellable packer?

A swellable packer is openhole isolation equipment, covered by API Spec 19OH, which sets its own validation requirements; ISO 14310 and API 11D1 do not cover it. Ask which document any grade on a swellable packer refers to. Confirm the seal in the hole the same way as for any packer, by the barrier test once it has swelled.

Every answer here is open to the same test as a supplier's claim, and the next block names who stands behind them.

Who wrote and reviewed this page, and how was it checked

This page was prepared and reviewed by the engineering and quality team at the Manjusar and Savli GIDC plant of Maximus OIGA Private Limited, Vadodara. It was checked against the documents listed below.

• API Spec 11D1, fourth edition, with Addendum 1
• ISO 14310, second edition
• API Spec 19OH
• ISO 14998
• API Spec 19AC

The method: the documents were read by designation, edition and published scope. The grade definitions were taken from API's Addendum 1 and the public summaries of the ISO 14310 grades. The API Composite List's field and status names were used as the register writes them, and no company or product was rated.

If you find an error on this page, send a correction through the site's contact page, whether you are a reader, a supplier or a standards body. The page will be amended.

What should you do with the next V0 claim on your desk

Take the claim through the ten checks on this page before it reaches a signature.

Run these checks on any supplier, including us.