Lesson 14 WelderQuals New2

API 510 Preparatory ClassAPI 510 Preparatory Class

Lesson 14Lesson 14

Welder’s QualificationWelder’s Qualification

SECTION IX

Welder’s Qualifications / Essential Variables

We will discuss all of the welder’s essential variables listed in QW-353 for the SMAW process. Please turn to page 52 of Section IX.

QW-353 Shielded Metal-Arc Welding (SMAW)

Essential Variables

Paragraph

QW 402

Joints .4

QW 403

Base Metals .16

.18

QW 404

Filler Metals .15

.30

QW 405

Positions .1

.3

Brief of Variables

Deletion of Backing

Change Pipe Diameter

Change in P Number

Change in F Number

Change in weld t deposited

Addition of a position

Change from vertical Up to Down or Down to UP progression


Welder Essential Variables

The first essential variable listed is – Backing (Removal of).

If a welder is qualified using any type of backing, and asked to perform an open root weld he must retest without backing to be qualified to perform the welding.

The Code definition of backing is welding with a backing bar or retainer, welding double sided welds where the weld metal of the first pass is used after gouging/grinding as weld metal backing for the balance of the weld. Fillet and partial penetration welds are also considered welding with backing.



The next inline is a change in Pipe Diameter qualified. As pipe diameters become smaller the difficulty for a welder is increased resulting in a higher skill level requirement.

So this translates to a change in diameter to one smaller than qualified by the welder’s pipe coupon on a previous test with this process.

The ranges of pipe diameters qualified are given in Section IX, turn to page 143 in Section IX.

QW-452.3 GROOVE-WELD DIAMETER LIMITS

As we can see:

1. Under 1 inch (25mm) qualifies the diameter down to the size welded to unlimited diameter, because it is only easier for the welder as the diameter of the Pipe welded increases.

2. From 1 inch (25mm) to 2-7/8 inch (73mm) qualifies 1 inch to unlimited.

3. Over 2-7/8 inch (73mm) qualifies 2-7/8 inch to unlimited.


Quiz

1. If a welder qualified on a NPS 6 inch pipe coupon the range of diameter qualifications in production with the WPS he tested to will be _________.

2. If tested with a NPS 2 inch coupon what is his minimum and maximum diameter range is ________.


Quiz

1. If a welder qualified on a NPS 6 inch pipe coupon the range of diameter qualifications in production with the WPS he tested to will be 2-7/8” to unlimited.

2. If tested with a NPS 2 inch coupon what is his minimum and maximum diameter range is 1” to unlimited.

QW-353 Welder Essential Variables

P-Numbers. P-Numbers serve to group metals by mechanical and chemical properties. So it is reasonable to think that not all metals can be welded using the same technique, or have the same level of difficulty for welders.

There are three basic P-No. groupings for welder qualifications. If a welder changes to a P-No. group that he/she has not qualified for then a retest is required. We will have a more thorough lesson on Alternate Base Metals later in this course.

QW-432 F Numbers

We have now arrived at the Filler Metal Number or F- Number. F- Numbers are a grouping of electrodes and filler metals that weld in a similar way and in general present more or less difficulty for a welder. In other words some F-Number filler metals require different skills than others and must be qualified individually in most cases.

QW-432 F Numbers

The table of F Numbers coming up is read in the following way…• EXX18 stands for all SMAW electrodes ending in 18 such as E-7018, E-7018-A1, 8018-B1 etc..

So all of the above are F-Number 4• EXX10 would be E-6010 with an F-Number of 3• The XX is the tensile strength 70,000 PSI ect.

Turn now to Page 132 of Section IX

QW-433 Alternate F-Numbers for Welder Performance Qualifications

Changing the F Number for a welder may affect his ability to weld and require requalification. There are some provisions for using lower F-Numbers when qualifying with numbers 2 to 4 but, there are restrictions on those qualifications.

Turn now to Page 137 of Section IX


Examples

1. Using the table QW-433, if a welder qualifies without backing with an electrode assigned to F-Number 4. What F-Numbers can he use with backing in a production weld?

2. What F Numbers can he weld without backing?


Solution

1. He can weld F-Numbers 1 through 4 with backing. Going right across the row titled “Qualified With” to F-Number 4 without backing then down to each x in the boxes, then left to read the “Qualified For” Column we find F Numbers 1, 2, 3 and 4 with backing.

2. Also the “Qualified For” F Number 4 without backing is included which makes sense as he performed that weld for his test.


Notice that the large table only addresses F-Numbers 1 through 5. The rest of the F-Numbers are in a small table along with notes beneath the large table. Let’s have a look at those.

QW-433 Alternate F-Numbers for Welders

QW-452.1 (b) Thickness Of Weld Metal Deposit

The fifth essential variable listed is change in thickness of Weld deposit.

A welder is restricted by the amount of weld metal he deposits during his performance qualification test with a particular, welding process, electrode/filler metal F-number in a P-Number base metal combination. We will now have a look at those rules.

Turn to Page 142 of Section IX


The column ‘Thickness t, of weld metal in the coupon’ refers to the amount of weld metal from a process or a filler metal. Perhaps a bit of E-6010 and the rest E-7018. Perhaps GTAW root and SMAW fill passes and cap.


Example

Assume one welding process, SMAW and one electrode E-7018 using a P-No.1 pipe.

A coupon thickness of 3/8 inch was welded using E-7018. In the column on the right titled ‘Thickness of weld metal qualified’ we see 2t, so 2 x 3/8” = 3/4” this is the maximum amount of E-7018 (F-No. 4) , that the welder can deposit in production.


Suppose now the coupon is 1/2” thick and a welder welds it with 100% E-7018 using 3 weld layers, we see that welder’s limit of deposited weld metal with an F-No.4 is the maximum to be welded.


Another combination in the 1/2” coupon.

1/8” of E-6010 (F-No.3) and 3/8” of E-7018. By the first column 2 x 1/8” = 1/4” of E-6010 (F-No.3) and 2 x 3/8” = 3/4” of 7018 (F-No.4). The welder can deposit up to 1/4” of any F-No.3 and 3/4” of any F-No.4 with any production WPS he is otherwise fully qualified for, meaning position, diameter, P-No., backing, progression etc.


Quiz

How can we qualify a welder for unlimited thickness with both F-No.3 and 4 in a single coupon? If he or she welds a coupon that is at least ___ thick and deposits at least___” of E-6010 and at least ___” of E-7018 using a minimum of ____ layers of each filler metal.

* Hint See Note 1 of table QW-452.1(b)


Solution

If he or she welds a coupon that is at least 1” thick and deposits at least 1/2” of E-6010 and at least 1/2” of E-7018 using a minimum of three weld layers for each filler metal.

The welder can deposit unlimited t with any F-No.3 and/or F-No.4 with any production WPS he is otherwise fully qualified for such as, position, P-No., backing, diameter, progression etc.

QW-353 Welder Essential Variables

The next essential variable listed is Position.Consider the welding positions versus the welder test positions for a moment. We will use pipe test coupons. Positions for pipe tests are designated by an alphanumeric such as 1G, 1 designates the coupon orientation, in this example the pipe is on the horizontal and is rotated/rolled beneath the welder and is considered to be flat welding. The G means a groove butt weld. The others are 2G, 5G and, 6G.

Turn to Page 148 QW-461.4 in Section IX.

QW-461.4 Groove Welds in Pipe – Test Positions

The more difficult the test position, the more positions a welder can perform. The four positions for welding are Flat, Horizontal, Vertical and Overhead.

These are referred to as:

F,H,V,O


There are corresponding pipe and plate test positions that qualify a welder for F,V,H, and O. We will use pipe in the examples.

1G qualifies F (Rotated)

2G qualifies H

5G qualifies F, V, and O

6G qualifies F, V, H and, O (this yields all positions)


Section IX allows combining test positions to produce an all position welder. Therefore if a welder tests in 2G and 5G he/she was tested for all positions.

2G covers H and 5G covers F, V, and O

Which is equal to 6G that qualifies F, V, H and, O. Either of these two yields an all positions welder.

QW-469.1 Performance Qualifications - Position and

Diameter Limitations

All of this information is compiled into one table.

In this way you can go straight to a one page table and review a Welder Performance Qualification (WPQ) for position and diameter qualifications.

Turn to Page 151 Section IX

Notice the entry on the top row right Position and Type Weld Qualified. [Note (1) ]Below that GrooveBelow Groove exists two sub-headingsPlate and Pipe Over 24 inches and Pipe less than or equal to 24 inches. Ignoring Fillets because any welder qualified for groove 1G is qualified for the same fillet 1F.

To the left we have Qualification Test

Which has the sub-headings Weld and Position

We will use the Pipe-Groove [ Note (3)] row. Starting at the top of the table in the Qualification Test column move down and stop at the 1G entry below. To the right we see the entries F F F ignore fillets.

Move up at the first F and find Plate and Pipe Over 24 in. O.D. is qualified

Move up from the second F and find Pipe less than or equal to 24 in. O.D. is qualified. See [ Note (3)]

Pipe less than or equal to 24 in. O.D. is qualified. See [ Note (3)]

Note (3) See diameter restrictions in QW-452.3, QW-452.4, and QW-452.6

Notice that while the welder can weld on pipe in the “position qualified” he or she is still restricted by the diameters given in the table below on,Pipe less than or equal to 24 in. O.D..


The last essential variable listed is Progression.

This is as simple as it gets.If a welder welds Vertically Up (Uphill) during a particular test he is only qualified for Vertically Up.

Should the welder be required to weld Vertically Down (Downhill) he will be required to weld a test coupon (keeping other variables the same) welding Vertically Down.

The reverse is also true, qualify Downhill and you must weld another coupon to qualify Uphill.

QW-353 (SMAW) Welder Essential Variables

Quiz

A welder performs a test on a NPS 4” (4.5”) pipe coupon in the 6G position. The coupon is Schedule 160 and has a wall T of 0.531”. The welder will use SMAW with E-6010 for the root pass for a total weld deposit t of .125” (1/8”). The balance of the weld deposit t (.406”) will be performed using 3 weld layers of E-7018 filler metal. Obviously no backing will be used. All welding will be uphill during the test. What are his qualifications as listed in table QW-353?

(SMAW) Welder Essential Variables

Continued

The test qualifies ___ positions with a minimum diameter of ______ and a maximum of _______. The test also qualifies the welder to deposit ___ inches of F- No. 3 and ____inches of F-No.4.

The welder will also be qualified to weld _____or _______backing. The thickest weld he can make using this combination in production is__________. The welder’s production welds must made using _______ progression.

(SMAW) Welder Essential Variables

Solutions

The test qualifies all positions with a minimum diameter of 2-7/8” and a maximum of unlimited. The test also qualifies the welder to deposit .250” inches of F- No. 3 and .812” inches of F-No.4.

The welder will also be qualified to weld with or without backing. The thickest weld he can make using this combination in production is .250 +.812 or 1.062”. The welder’s production welds must be made using uphill progression.



The next series of slides address the alternate base materials for welder qualifications. As you will see a welder can test for example on a P-No. 1 base material with a selected F-No. filler metal and, under the rules of Section IX he can weld many other P-Numbers using the F-No. used for the test, maintaining all the other essential variables for the welder, position, diameter, etc.

SECTION IXQW 423 – Turn to Page 131

Alternate Base Materials for Welder Qualification

Versus Base Metal Qualified

QW-423 Alternate Base Metals for Welder Qualification

Base metals used for welder qualification may be substituted for the metal specified in the WPS in accordance with the following in-text table.

When a base metal in the left column is used for welder qualification, the welder is qualified to weld all combinations of base metals in the right column. Including unassigned metals of similar composition to these metals.

Warning

Base Metal (s) Used forWelder Qualification

P-No. 1 through P-No. 11, P-No. 34, or P-No. 41 throughP-No. 47

P-No. 21 through P-No. 25

P-No. 51 through P-No. 53 or P-No. 61 through P-No. 62

Base Metal (s) forwhich the Welder is Qualified

P-No. 1 through P-No. 11, P-No. 34, or P-No. 41 throughP-No. 47

P-No. 21 through P-No. 25

P-No. 51 through P-No. 53 or P-No. 61 through P-No. 62

QW-423 Alternate Base Metals for Welder Qualification

So, all we need to do is qualify a welder to weld any P-No. from the list and he can weld all of the others. This would be great!

There is however a problem with this theory. Welders are also limited by the Filler Metal Number (F-No.) used during a test.

If a welder qualifies on any P-Number from P 1 through P 11, P 34 or P 41 through P47 he/she is qualified to weld any of those metals together. Be warned this is further limited by the F-number (s)!

If a welder qualifies on P 21 to P 25 he/she is qualified to weld any of these metals together or any combination of these aluminum alloys together!

If a welder qualifies on P 51 to P 53 or P 61 to 62 he/she is qualified to weld any of these metals together or in any combination of Titanium or Zirconium alloy!

In theory a welder could be qualified for all the listed base materials by welding just three (3) coupons. Remember our lesson on Filler Metal Numbers (F-Numbers). This is where the welders limitations become very important.

One of the essential variables for a welder is the F- Number of the electrode he qualifies with during a given test.

Suppose a welder qualifies with SMAW using an F-No.4 electrode the test coupon is a P-No.1 base material.

The welder has qualified to weld P No. 1 to 11, 34 or 41 through 47. So let’s have him weld one of the nickels, a P-No.41. Assume it will be required to make the weld with a filler metal that is designated as a F-No.41 in Section IX. There is a problem , he has not qualified any of those metals with a F-No.41 filler metal. He would have to prove his skill with the F-No.41 filler metal.

He is qualified for SMAW using a F-No.4 electrode not F-No.41. The welder will have to test again on any of those metals using a SMAW electrode designated as a F-No.41, why because the F-Numbers 4 and 41 are considered to require different skill levels to weld. The F-Number is a welders essential variable as well as a procedures.

Welders are limited by all of the following essential variables (skill issues), which are in Section IX for the welding processes listed on page 52.


Essential Variables

Paragraph

QW 402 .4

Joints

QW 403 .16

Base Metals .18

QW 404

Filler Metals .15

.30

QW 405 .1

Positions .3

Brief of Variables

Deletion of Backing

Change Pipe Diameter

Change in P Number

Change in F Number

Change in weld metal t deposited

Addition of a position

Change from vertical Up to Down or Down to UP progression

Simply put the welder must qualify all of his/her essential variables, not just be qualified to weld a particular P-Number. In our example he/she is disqualified for the nickel alloy weld because of the required F-Number qualification being F-No.41 as listed on the WPS/PQR.

A welder is limited by, process, pipe diameter, P- Number, F- Number, weld metal thickness, position, backing and progression.

All of these Essential Variables must meet the requirements of the WPS to be used in the production weld.

Destructive Testing of Welder’s Qualification Coupons

There are three items that must be addressed when performing destructive testing of a welder’s test coupon.

1.The type of the specimens required.

2. How many specimens are required.

3. Where in the test coupon specimens shall be taken from.

These items are listed in Article IV Welding Data of Section IX in a tabular form, 452.1(a) and are accompanied by notes referencing paragraphs found in Article III, of Section IX .The type and number a listed in that paragraph.

Turn now to Page 142 of Section IX.

Notice that the notes underneath the table do the following things:

General Note: Defines the “Thickness of the Weld Metal” and disallows using the reinforcement as part of the thickness deposited.

Note 1. Specifies the number of coupons used for the listed welder pipe groove test positions, and thereby differentiates pipe from plate coupons.

Note 2. Coupons tested by face and root bends. Limits the type of weld bend coupons that can be used when doing combination welder or process tests a single coupon. Combinations outside of this description will require side bends.

Note 3. Allows the substitution of side bends for face and root when the coupon is 3/8” to less than 3/4”.

We will now examine the figures referenced in QW-452.1(a) for removal of Welder’s Performance Coupons.

Turn to Page 173

Next an example of the coupons required for a 2G and 5G test in a single coupon which will qualify a welder for all four of the positions, Flat, Horizontal, Vertical and, Overhead just the same as the single 6G test.

This coupon requires 6 bend specimens instead of the usual 4, taken from the locations indicated in the graphic.

We will now examine the figures referenced in QW-452.1(b) for Welder’s “Thickness of Weld Metal (t) Qualified”.

Turn to Page 142

Notice that the welder must deposit at least 1/2” in a minimum of three layers/passes to be qualified for unlimited thickness in production. All thickness below 1/2” follow the 2 x t rule.

Example:

The welder deposits 3/8” he is qualified to weld up to 3/4” in production welding with the process and filler metal used during his test. Also, as stated previously in addition he will be limited by diameter, progression, backing and, position.

Combination tests are described in notes 1, 2, and, 3.

Example:

Note 1: Two welders deposit 1/2” each, both used three layers in a single 10” Schedule 140, 1” thick coupon with SMAW F-No. 4 electrodes. They will each be qualified to weld unlimited thickness in production with that process and F-No. using the position, progression, backing and, diameter used during the test. They could also have used different F-No.s and/or processes and could have been qualified unlimited thickness based on the test they performed.

Example:

Note 2: Two welders deposit 1/2” each, both used three layers in a single 1” thick coupon with SMAW F-No. 4 electrodes. They will each be qualified to weld unlimited thickness in production with that process and F-No. using the position, progression, backing and, diameter used during the test. They could also have used different F-No. s and/or processes and would have been qualified unlimited thickness base on the test they performed.

Example:

Note 3: Two welders deposit 1/2” each, both used three layers in a single 1” thick coupon with SMAW F-No. 4 electrodes. They will each be qualified to weld unlimited thickness in production with that process and F-No. using the position, progression, backing and, diameter used during the test. They could also have used different F-No. s and/or processes and would have been qualified unlimited thickness base on the test they performed.

Example - Billy Bob Welder’s performance test was made under the following conditions using Big Welding Company’s WPS CW-1010 :

1. P-Number 1 pipe coupon2. Pipe diameter NPS 8” (8.625”)3.Thickness 0.500” 4. 6G test position5. Uphill progression6. F-No.4 (SFA 5.1) 3 layers of weld metal7. Process SMAW Only

Next we fill out the of Welder’s Performance Qualification Form QW-484 (WPQ) for Billy Bob Welder.

Remember, a welder has only Essential Variables and for SMAW they are:

1. P-Number2. F-Number3. Diameter4. Backing, with or without and, without qualifies both for a given F-Number and lower F-Numbers in some instances.5. Vertical Progression (Uphill or Downhill)6. Position7. Weld Metal thickness

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Lesson 14 WelderQuals New2