William Galvery

Welding Essentials


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Preparation Terminology

       What are the principal parts of V-and U-groove joint preparations?

      •Depth of bevel

      •Size of root face

      •Root opening

      •Groove angle

      •Bevel angle

      See Figure 4–3.

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      Edge Shape Combinations

       What are the most common combinations of joint preparations for butt joints?

      See Figure 4–4.

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       What common preparations are used on corner joints?

      See Figure 4–5.

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       What weld preparations are used on T-joints?

      See Figure 4–6.

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       What are the weld preparations for edge joints?

      See Figure 4–7.

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       What are the weld preparations for lap joints?

      See Figure 4–8.

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      Selection of Joint Preparation

       What determines which joint preparation geometry to use?

      The factors are:

      •Kind of joint loads (tension, compression, shear, or torsion).

      •Level of joint loading.

      •Static or dynamic loading.

      •Thickness and type of the metals joined.

      •Welding position.

      •One side/both sides access to the weld.

      •Skills of welders.

      •Trade-offs between joint preparation costs/filler metal costs/welding labor costs; each joint and geometry carries its own combination of total cost.

       What is an excellent source of weld joint design and preparation information for steel?

      The Structural Welding Code—Steel, ANSI/AWS D 1.1 is a document with over 50 detailed drawings for pre-qualified joint designs using SMAW, GMAW, and FCAW for steel plate. Joints for submerged arc welding (SAW) are also included. There is additional information for joining tubing, weld testing, and inspection. The document is available from the AWS.

      Joint Preparation

       What are the most common weld preparations?

      See Figure 4–9.

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      Parts of the Weld

       What are the terms used to describe the parts of a groove weld?

      •Effective throat or size of weld

      •Face

      •Toe

      •Face Reinforcement

      •Root Reinforcement

      See Figure 4–10.

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       What are the terms used to describe the parts of a fillet weld?

      •Leg or size of weld

      •Face

      •Toe

      •Convexity

      •Root penetration

      •Fusion zone

      •Leg of a fillet weld

      •Root of the weld

      •Actual throat and theoretical throat

      See Figure 4–11.

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       CONVEX FILLET WELD

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       CONCAVE FILLET WELD

      Figure 4–11BParts of a concave fillet weld

      Welding Positions

       How are welding positions plate designated?

      They are divided by the position of the axis of the weld with respect to the horizontal and whether they are made on plate or pipe. They are used to designate positions for testing of welders and the application of a specific process. See Figure 4–12.

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       What are the welding positions for pipe?

      See Figure 4–13. Note the difference between welding positions A , and C: In position A, (1G) the pipe may be rotated about its longitudinal axis to provide access to any part of the weld joint allowing the welder the opportunity to weld the entire pipe in the flat (1G) position; in position C, (5G) the pipe is fixed and cannot rotate forcing the welder to weld upward or downward vertically, flat on the top and overhead on the bottom; position