CWB Test Procedures Flashcards
What does CWB stand for, and what role do they have for weld certification?
CWB = Canadian Welding Bureau
They are an organization that certifies and registers qualified companies and welders for specific weld procedure
What does it mean to have “S Classification” for CWB?
This refers to the welders ability to weld from one side with backing.
How thick should the plates and backing bar be for CWB purposes?
Plate: 3/8” (10mm)
Backing bar: 1/4” (6.4mm)
What is a general rule when it comes to placement and size of each bead?
Always achieve penetration in the narrowest portion of the joint
How far should your stop/starts be placed on CWB tests?
1 1/2” (38mm)
What is does PQR stand for, and what is its purpose?
PQR = Procedure Qualification Record
A WPS is backed by a PQR. It is a record of a weld test that is completed using the variables listed in the WPS and has been throughly tested to ensure it consistently yields good welds.
Note: The CWB has many prequalified welding procedures and those do not require a PQR
What does WPDS stand for, and what is its purpose?
WPDS = Welding Procedure Data Sheet
The CWB uses a WPDS in conjunction with a WPS which details the welding parameters and ranges for a weld.
While CWB testing, how much plate are you to discard on the ends?
3/4” (19mm)
What is the maximum fillet weld size for CWB testing?
5/16” (8mm) max
What is a guided bend test?
It’s meant to check soundness and ductility. A guided bend test uses a jig assembly to bend a weld coupon to a certain radius
What size are the guided bend tests prepared to?
1 1/2” (38mm)
How many face and root bends are there in CSA Standard W47.1?
Two root bends
One face bend
When are you to do a side bend in CWB testing?
When the thickness of the material is more than 3/8” (10mm)
How large should your root gap be for CWB 1GF testing?
1/2” (13mm)
How large should your root gap be for a 2G with backing?
5/16” (8mm)
How large should your root gap be on a 3GF for CWB?
1/2” (13mm)
What are some advantages of backing material?
- Higher heats that promote full fusion
- Fast welding speeds, resulting in reduced distortion
- Shapes the root contour bead
- Easier to fit and align
How should you prepare 3/8” (10mm) plate for a 1GF, 2 with backing, or 3GF?
One edge is to be beveled to 30 degrees and left with a feather edge. The other side is to be prepared to a square edge.
What size can you make your tacks for SMAW groove weld purposes?
1/4” - 3/8” (6.4mm - 10mm)
Which electrode do you use for CWB SMAW groove testing?
E4918 (E7018)
When doing guided bend tests, what should you do with the backing bar after the weld is completed?
Before the coupon can be bent the backing bar must be removed to be flush with the parent material. Grinding marks should be transverse to the weld being tested.
Any weld that is not prepared this way has a risk of notch effect and leading to failure of the specimen.
What is the tolerance for a crack or open defect on a bent coupon?
More than 1/8” (3.2mm) in length, measured in any direction on the convex surface of the bent coupon is a failure.
