API 1104 PIPELINE

API 1104 Pipeline Welder Qualification Testing

Mail-in API 1104 pipeline welder qualification for pipeline contractors, oil and gas operators, and cross-country transmission crews. Your welder runs the coupon at your facility under an approved WPS. Ship it to Atlanta. We handle CWI inspection, accredited bend and nick-break testing, and official WPQ documentation.

✓ We Test Your Coupons • ✗ We Are Not a Welding School • ✓ Official API 1104 WPQ Records Issued

✆ (404) 860-1288 Get a Quote How It Works

API

Standard 1104

Pipeline welding code

All

Positions

Fixed pipe, all orientations

WPQ

Documentation

Official record issued

AWS

CWI Inspected

Every coupon

✓ API Standard 1104 ✓ 49 CFR Part 192 / Part 195 ✓ Transmission & Gathering Lines ✓ Uphill & Downhill Progression ✓ Nationwide Mail-In Service

Pipeline welder in full PPE welding large diameter steel pipe outdoors during cross-country pipeline construction — API 1104 governs pipeline welder qualification for transmission lines, gathering systems, and distribution mains.

What Is API 1104 and Who Needs This Qualification?

API Standard 1104, published by the American Petroleum Institute, is the governing welding standard for pipeline construction in the United States and internationally. It covers welding of cross-country transmission pipelines, gathering systems, distribution mains, compressor stations, pump stations, and associated facilities. If steel pipe carries natural gas, crude oil, refined petroleum products, or water under pressure in a pipeline environment, API 1104 is almost certainly the applicable standard.

Any welder who performs production welds on pipeline construction covered by API 1104 must hold a current qualification under that standard. This applies to:

Cross-country natural gas and liquid petroleum transmission line welders
Gathering system and midstream pipeline construction crews
Distribution main and service line welders working under utility operators
Compressor station and pump station piping welders
Maintenance and repair welders working on existing pipeline infrastructure
Tank farm and terminal piping welders where the operator specifies API 1104

Regulatory Requirement: In the United States, pipeline construction subject to 49 CFR Part 192 (natural gas) or 49 CFR Part 195 (hazardous liquids) is regulated by the Pipeline and Hazardous Materials Safety Administration (PHMSA). These regulations require welding to be performed per a qualified welding procedure and by qualified welders — API 1104 is the industry standard that satisfies this requirement. Non-compliance is not an option.

API 1104 vs. AWS D1.1: Know the Difference

These are two different codes for two different industries. Using the wrong qualification is a compliance failure, not a technicality. Here is how they compare:

Factor	API 1104	AWS D1.1
Primary Application	Pipeline construction & maintenance	Structural steel fabrication
Governing Body	American Petroleum Institute	American Welding Society
Test Coupon Type	Pipe only	Plate or pipe
Plate Test Covers Pipe?	No	Partially
Progression (Up/Down)	Both — must qualify each	Position-based coverage
Downhill Progression Covered?	Only if specifically qualified	N/A — not a separate variable
Nick-Break Test	Yes — common for thin wall	Not standard
Regulatory Backing	49 CFR 192/195 (PHMSA)	Building/bridge codes
Cross-Qualification	Does not satisfy D1.1	Does not satisfy API 1104

Important: If your project specs call for API 1104, an AWS D1.1 qualification card will not satisfy the requirement. Pipeline operators and their inspectors know the difference. Get the right qualification.

API 1104 Section 6 — Qualification Structure

Section 6 of API 1104 covers welder qualification entirely. Understanding its structure is critical to knowing what you need to test and what your qualification covers.

6.1 — General

Establishes that each company must maintain a current record of each qualified welder and the procedures they are qualified to use. Qualification is employer-specific — a welder qualified under Company A's procedures must requalify when moving to Company B unless specific arrangement is made.

6.2 — Qualification Variables

Defines essential variables that trigger requalification when changed: welding process, pipe diameter group, wall thickness group, filler metal class, joint design, position, and welding progression direction. Downhill and uphill are treated as separate essential variables — qualifying one does not cover the other.

6.3 — Qualification Tests

Specifies the test coupon configuration, number of specimens required, and test methods. The test must be performed in accordance with an approved welding procedure specification. WeldCertTest evaluates all coupons per this section using visual examination, guided bend testing, and nick-break testing as applicable.

6.4 — Acceptance Criteria

Sets visual and mechanical acceptance criteria. Visual inspection checks for cracks, incomplete fusion, surface porosity, undercut, and weld profile compliance. Bend specimens must show no cracks or other defects exceeding 3 mm (1/8 inch). Nick-break surfaces must show complete fusion, no cracks, and porosity within specified limits.

6.5 — Records & Continuity

Requires the company to maintain qualification records for each welder. Qualification expires if the welder has not used the qualified process for six consecutive months. The record must show continuous use. When qualification expires, a new test coupon is required — there is no grace period or shortened path back.

6.6 — Automatic Welding

Addresses qualification of automatic and semiautomatic welding operators — a separate qualification path from manual welder qualification. If your project involves mechanized or automated welding systems, different qualification requirements apply. Contact us to discuss your specific application.

API 1104 Position Coverage — What Your Test Qualifies

Position coverage under API 1104 is determined by the orientation of the pipe axis during the qualification test. Testing on the most challenging position gives the broadest coverage for field work.

Test Position	Pipe Axis	D1.1 Equivalent	Positions Covered	Best For
Axis Horizontal, Fixed	Horizontal — pipe cannot rotate	5G / 6G (without incline)	All positions	Cross-country pipeline, all field work
Axis Inclined, Fixed (45°)	45° incline — comparable to 6G	6G	All positions	Broadest single qualification available
Axis Vertical	Vertical — pipe end up	2G	Horizontal only	Limited — horizontal position production welds
Axis Horizontal, Rotating	Horizontal — pipe rotates (flat position)	1G	Flat (1G) only	Shop rotator work only — not for field

Field Recommendation: For pipeline construction crews doing any field work, qualify on the horizontal fixed (5G equivalent) or 45° inclined (6G equivalent) position. This covers all field positions. A rotating or vertical-axis test significantly limits where you can weld in production.

Pipe Diameter Coverage Groups

API 1104 groups pipe by outside diameter. Your test coupon OD determines the range of pipe you are qualified to weld in production.

Test Coupon OD	Production OD Qualified	Notes
Under 2⅜ inch	Up to test OD only	Very limited — small distribution pipe
2⅜ inch to 4½ inch	Up to 4½ inch OD	Small gathering and distribution lines
Over 4½ inch to 12¾ inch	Over 4½ inch up to 12¾ inch	Medium diameter transmission and distribution
Over 12¾ inch	Unlimited OD	Full coverage — recommended for transmission line welders

Common Processes and Electrodes — API 1104 Pipeline Welding

The welding process and filler metal are essential variables under API 1104. Qualifying with one process does not cover another. Here are the most common combinations used in pipeline qualification testing.

SMAW — Stick (Downhill)

The dominant process for cross-country pipeline construction. Cellulosic electrodes — E6010 for stringer and hot passes, E7010 for fill and cap — are the backbone of transmission line welding. Fast deposition, excellent penetration, field-rugged. Downhill progression is standard. Must be specifically qualified downhill.

Common electrodes: E6010, E7010-P1, E8010-P1

SMAW — Stick (Uphill)

Low-hydrogen electrodes uphill are used in higher-strength pipe applications, sour gas service (H₂S environments), and some repair scenarios where toughness requirements exceed what cellulosic electrodes deliver. E7018 and E8018 are common. Must be qualified uphill — does not carry over from downhill qualification.

Common electrodes: E7018, E8018-C3, E9018-G

GMAW / FCAW

Self-shielded FCAW and solid wire GMAW are used in certain pipeline applications, particularly shop fabrication of fittings and offshore pipeline work. Dual-shield FCAW (gas-shielded flux core) offers high deposition rates for large diameter wall. Each process must be separately qualified under API 1104.

Common wires: E71T-8 (self-shielded), ER70S-6 (GMAW), E71T-1 (FCAW-G)

GTAW — TIG Root Pass

TIG root passes are common in process piping tied to pipeline systems — compressor stations, meter sets, and high-pressure fittings where a perfect root is required. Often combined with SMAW fill and cap (GTAW+SMAW combination procedure). Each process in the combination must be qualified.

Common filler: ER70S-2, ER70S-6

Progression Is a Separate Variable: Under API 1104, welding progression (uphill vs. downhill) is an essential variable. A welder qualified downhill with E6010 is not qualified uphill, even with the same electrode. If your work requires both, you need both qualifications. Call us to discuss qualifying for multiple procedures in a single testing session.

How WeldCertTest Tests Your API 1104 Pipeline Coupon

Every API 1104 test coupon we receive goes through a documented examination sequence performed by our Certified Welding Inspector. Here is exactly what happens when your coupon arrives.

Receiving and Documentation — Your coupon is logged in, welder identification is confirmed, and the pipe OD, wall thickness, and reported welding process are recorded. The coupon is marked for traceability through the examination process.
Visual Examination (Section 9.3 / Section 6.4) — The CWI performs visual inspection of the weld crown, root face (if accessible), and weld profile. We check for cracks, incomplete fusion, incomplete penetration, surface porosity, undercut exceeding API 1104 limits, and any burn-through. Visual results are documented before any mechanical specimens are cut.
Specimen Cutting — Test specimens are cut from the required locations around the pipe circumference. Specimen quantity and location follow API 1104 Section 6.3 requirements based on pipe OD. Larger diameter pipe requires more specimens to represent the full circumferential weld.
Guided Bend Testing — Root and face bend specimens are bent in our guided bend fixture to the required mandrel diameter. The bent specimens are examined for cracks, incomplete fusion, and other defects. Acceptance criteria per Section 6.4 — no cracks or defects exceeding 3 mm (⅛ inch) in any direction.
Nick-Break Testing — For applicable pipe sizes and joint configurations, nick-break specimens are notched and fractured. The fracture surface is examined for porosity, slag inclusions, incomplete fusion, and cracks. API 1104 specifies maximum allowable porosity by size and distribution on the fracture face.
WPQ Documentation — Upon passing, we issue the Welder Performance Qualification record documenting all essential variables, test results, and examiner certification. This is your official qualification document.

Failing the Test: If a coupon fails, we document which specimens failed and the specific rejection reason. This gives you actionable information for your welder — not just a failed result. Many welders correct a specific technique issue and retest successfully. We'll discuss what we saw and what to address before the next test coupon.

Preparing Your API 1104 Test Coupon

Your test coupon must be welded in accordance with your company's approved API 1104 welding procedure specification (WPS). Before shipping:

Confirm your WPS is approved and covers the pipe OD, wall, material, process, and position you are testing
Use the correct electrode or filler wire classification listed on the WPS
Weld in the correct progression direction (uphill or downhill as specified)
Do not grind the weld crown flush — we need to see the as-welded surface for visual inspection
Mark the coupon with welder ID, date welded, position, and process before shipping
Package per our shipping instructions — pipe coupons need proper crating to arrive undamaged

Where API 1104 Qualification Is Required

API 1104 qualification is required wherever the operator or applicable regulations designate it as the governing welding standard. This covers a wide range of pipeline infrastructure types.

Application	Regulatory Requirement	Typical Pipe Size	Notes
Interstate Natural Gas Transmission	49 CFR Part 192 (PHMSA)	12¾" to 48"+ OD	Federal DOT jurisdiction — strict documentation requirements
Intrastate Gas Distribution	State pipeline safety regulations	2" to 24" OD	State-regulated — most states adopt API 1104
Hazardous Liquid Pipelines	49 CFR Part 195 (PHMSA)	4" to 48"+ OD	Crude oil, refined products, CO₂, anhydrous ammonia
Crude Oil Gathering Systems	Operator spec / 49 CFR Part 195	2" to 20" OD	Midstream operators typically require API 1104
Natural Gas Gathering	49 CFR Part 192 (regulated); operator spec (unregulated)	2" to 20" OD	Regulation depends on location class and pressure
Compressor Station Piping	49 CFR Part 192 / operator spec	Varies	Often includes both API 1104 and ASME B31.8 requirements
Offshore Pipeline	API 1104 + BSEE regulations	4" to 36"+ OD	Bureau of Safety and Environmental Enforcement oversight
Pipeline Repair Welding	ASME B31.4 / B31.8 / 49 CFR	Existing pipe OD	In-service repair qualifications have additional requirements

Not Sure Which Standard Applies? If your project specs reference API 1104, that is your standard. If you're unsure whether your work falls under 49 CFR Part 192, Part 195, or a state equivalent, check with your project engineer or call the pipeline operator's welding engineer. Do not assume — the wrong qualification is a field rejection waiting to happen. Call us at (404) 860-1288 to discuss your specific project requirements.

API 1104 Essential Variables — When You Must Requalify

An essential variable is any change that, when made, invalidates your existing qualification. Any of the following changes requires a new test coupon and new qualification under API 1104 Section 6.2.

Welding Process

Changing from SMAW to FCAW, GMAW to GTAW, or any other process change requires requalification. Combined process qualifications must be tested as a combination.

Pipe OD Group

Moving to a smaller OD group than your qualification covers requires a new test. Testing on the largest group (over 12¾ inch) gives unlimited coverage going forward.

Wall Thickness

Production wall thickness exceeding the range covered by your test coupon requires requalification. Test on heavier wall to cover the broadest range.

Filler Metal Class

Changing electrode or filler metal classification requires requalification. Switching from E6010 to E7010, or from SMAW to FCAW wire, are separate essential variables.

Progression Direction

Downhill and uphill are separate essential variables. A downhill qualification does not cover uphill welding and vice versa. This is one of the most commonly overlooked qualification gaps.

Position

A rotating (1G) or vertical (2G) axis qualification does not cover the horizontal fixed position (5G/6G equivalent). Test on horizontal fixed to cover all field positions.

Joint Design

A significant change in joint design — such as adding or removing backing — may constitute an essential variable change depending on the specific modification.

Base Metal Group

API 1104 groups base metals. Moving to a different group or a higher strength grade than covered by your qualification may require requalification depending on the specific change.

API 1104 Welder Qualification — Frequently Asked Questions

Does API 1104 allow mail-in welder qualification testing?

Yes. API 1104 Section 6 governs welder qualification and does not require the examiner to witness the welding act itself. The standard requires that the test coupon be welded in accordance with the approved procedure and evaluated by a qualified examiner. The welder produces the test coupon at their facility and ships it to WeldCertTest for CWI visual inspection and accredited guided bend or nick-break testing. We issue the official WPQ documentation upon passing.

What positions does API 1104 welder qualification cover?

API 1104 Section 6.2 defines qualification positions based on pipe axis orientation. A welder qualified on a pipe with its axis horizontal and fixed (comparable to the 5G/6G position) is qualified to weld pipe in all positions. A qualification on pipe with its axis vertical covers only the horizontal position. Most pipeline contractors require the all-position qualification because field conditions vary continuously as welders work around large diameter pipe.

How is API 1104 different from AWS D1.1 for welder qualification?

API 1104 is specifically written for pipeline construction — cross-country transmission lines, distribution mains, gathering systems, and tank farm piping. AWS D1.1 governs structural steel welding — buildings, bridges, heavy equipment. The codes have different test specimen requirements, different acceptance criteria, and different coverage rules. An API 1104 qualification does not satisfy a D1.1 requirement and vice versa. If your work involves both pipeline and structural, you need separate qualifications under each code.

What are essential variables under API 1104 that require requalification?

Under API 1104 Section 6.2, essential variables that trigger requalification include: change in welding process, change in pipe outside diameter group or wall thickness group beyond qualified range, change in base material group, change in filler metal classification, change from one joint design to a significantly different one, change in position qualification coverage, and change in welding progression direction. Downhill and uphill are separate essential variables — qualifying one does not cover the other.

What is the difference between uphill and downhill progression in API 1104?

In pipeline welding, progression refers to the direction the welder travels while depositing each pass. Downhill (vertical down) is the dominant technique in cross-country pipeline construction because it is fast and suits cellulosic electrodes like E6010 and E7010. Uphill is used in some applications and produces a slower, more controlled puddle. API 1104 treats these as separate essential variables — qualifying downhill does not qualify uphill, and vice versa. You must specify which progression your approved welding procedure uses and qualify accordingly.

What pipe diameter and wall thickness ranges are covered by an API 1104 qualification?

API 1104 Section 6.2.2 groups pipe by outside diameter. Qualifying on pipe in the largest OD group (over 12.750 inch OD) qualifies the welder for all smaller diameter pipe. Qualifying on a smaller diameter group limits the welder to that group and smaller. Wall thickness qualification follows a similar stepped coverage approach — the test coupon wall thickness determines the maximum production wall thickness the welder is qualified to weld. Testing on the largest practical diameter and wall thickness gives the broadest coverage.

How long is an API 1104 welder qualification valid?

API 1104 Section 6.5 states that a welder qualification remains in effect indefinitely provided the welder remains employed by the company and continues to use the qualified process. If the welder has not welded with the qualified process for six months or more, the qualification expires for that process. The company is responsible for maintaining welder continuity records. If a qualification expires, the welder must requalify by completing a new test coupon meeting all current code requirements.

What testing is required to pass an API 1104 welder qualification?

API 1104 Section 6.4 requires the test coupon to pass visual examination and either guided bend testing or nick-break testing, depending on wall thickness. For thin wall pipe, nick-break specimens are commonly used. For heavier wall, guided bend root and face specimens are required. Visual examination checks for cracks, incomplete fusion, surface porosity, undercutting, and weld profile. The bend or nick-break specimens evaluate internal soundness, fusion, and penetration. WeldCertTest performs both visual and mechanical testing with documented results.

Can I qualify for API 1104 using a butt weld on plate instead of pipe?

No. API 1104 qualification is specific to pipe. The standard does not recognize plate test coupons as equivalent to pipe qualification. This is different from AWS D1.1, which allows plate tests to qualify welders for certain pipe applications. Under API 1104, the test coupon must be a pipe joint. This means all API 1104 qualification testing at WeldCertTest involves pipe coupons shipped to our facility.

What documentation is issued after passing an API 1104 welder qualification?

WeldCertTest issues a Welder Performance Qualification (WPQ) record documenting: welder identification, date of qualification, welding process, electrode or filler metal classification, pipe OD and wall thickness, joint design, position qualified, progression direction, and test results including visual and mechanical examination outcomes. The WPQ is signed by the CWI examiner and constitutes the official record of qualification. Your employer uses this document to demonstrate compliance to pipeline operators, inspectors, and jurisdictional authorities.

API 1104 Pipeline Welding — Key Terms

Understanding the terminology in API 1104 prevents qualification gaps and field rejections.

API 1104: American Petroleum Institute Standard 1104, Welding of Pipelines and Related Facilities. The primary welding standard for pipeline construction in the United States, referenced by 49 CFR Parts 192 and 195.
Essential Variable: A characteristic of the welding procedure or qualification that, when changed, invalidates the existing qualification and requires a new test coupon and new WPQ. Defined in API 1104 Section 6.2.
WPQ (Welder Performance Qualification): The official record documenting that a welder has successfully completed a qualification test under a specific welding procedure. Required to be maintained by the employer and presented to pipeline operators and inspectors.
WPS (Welding Procedure Specification): The written document that specifies the welding variables for a given application. Welders must test using an approved WPS. The WPS must be separately qualified under API 1104 Section 5 before it can be used for welder qualification testing.
Cellulosic Electrode: A high-cellulose SMAW electrode (E6010, E7010) characterized by deep penetration, fast freezing slag, and suitability for downhill progression. The dominant electrode type in cross-country pipeline construction. Produces a more fluid puddle than low-hydrogen electrodes.
Nick-Break Test: A destructive test method used in API 1104 qualification where a weld specimen is notched at the weld centerline and fractured. The fracture surface is examined for porosity, incomplete fusion, slag inclusions, and cracks. Common for thin wall pipe qualification.
Downhill Progression: Welding from the top of the pipe downward on each side — the welder travels in the direction of gravity. Standard for cross-country pipeline SMAW with cellulosic electrodes. Must be specifically qualified — not covered by uphill qualification.
49 CFR Part 192: Federal safety standards for transportation of natural gas and other gas by pipeline, issued by PHMSA. References API 1104 as the applicable welding standard for most pipeline welding operations under its jurisdiction.
PHMSA: Pipeline and Hazardous Materials Safety Administration — the U.S. DOT agency that regulates pipeline safety under 49 CFR Parts 192 and 195. PHMSA jurisdiction covers interstate natural gas and hazardous liquid pipeline systems.

Ready to Qualify Your Pipeline Welders?

Mail your test coupon. We handle CWI inspection, accredited bend and nick-break testing, and issue the official WPQ. Pipeline contractors nationwide trust WeldCertTest.

Get a Quote (404) 860-1288