고급용접기호 1편 Advanced WeldingSymbols

Weld All Around

The specification to weld all around requires that the weld be made to encapsulate the entire joint. In the case of a circular joint, the weld all around symbol is not required. The weld all around symbol consists of a circle that is placed over the intersection where the end of the reference line meets the arrow. Examples of weld all around welds and welding symbols are shown in Figures 10-3 and 10-4.

 

 

Field Weld

A field weld is defined by the American Welding Society (AWS) as “[a] weld made at a location other than a shop or the place of initial construction.”1 The field weld symbol consists of a flag that is placed at the intersection where the end of the reference line meets the arrow (see Figure 10-5).

Weld Length

Each weld, with the exception of spot and plug welds, has a length component. The weld length may be the entire length of the joint or some portion thereof. There are several different methods for providing the weld length information on a drawing. When the weld is to be the entire length of the joint, the length component is not required on the welding symbol. The welding symbol points to the joint requiring the weld, and the weld is made the entire length of that particular joint, as shown in Figure 10-6. If a weld is required to make a change in direction, an additional welding symbol or a multi-arrow symbol should be used. When the weld length is not required to extend the complete length of the joint, it can be defined by placing the required length to the right of the weld symbol. The welding symbol then points to the area of the joint requiring the weld. It may replace the standard length dimension, as shown in Figure 10-7.

 

Placing section lines in the area where the weld is to be placed can also be used in combination with standard dimensions and welding symbols to identify the required weld length and weld location. See Figure 10-8.

 

 

Intermittent Welds

An intermittent weld, also called a skip weld, consists of a series of welds placed on a joint, with unwelded spaces between each of the welds. The individual weld segments in an intermittent weld have a length and pitch component. The weld length is the linear distance of each weld segment. The length is shown in the welding symbol to the right of the weld symbol. The pitch is the center-to-center distance of each of the weld segments. It is shown to the right of the length on the welding symbol, with a dash between the two. This concept is shown in Figure 10-9. When intermittent welds are placed on both sides of a joint, they can be either directly opposite each other, known as a chain intermittent weld, or they can be offset, known as a staggered intermittent weld. The chain intermittent weld is shown in Figure 10-10. The staggered intermittent weld is shown in Figure 10-11.

 

 

Weld Contour Symbols

The contour of a weld refers to the shape of its face. A weld with a convex contour has a face that protrudes out in a convex shape from its toes; a weld with a concave contour has a face that is concave (sinks in from its toes); and a weld with a flush contour has a face that is flush with the base metal, or is flat from one toe to the other. When required, the contour symbol is added to a welding symbol so that it is oriented to mimic the required contour of the weld (see Figure 10-12). When a contour symbol is not added to the welding symbol, standard welding and shop practices should be followed.

 

Finish Symbols

Placing a finish symbol adjacent to the contour symbol specifies the method of making the contour. The finish symbols are made up of letters. The letters and their corresponding methods are listed below.

 

U = unspecified → This means that any appropriate method may be used.

G = grinding

M = machining

C = chipping

R =rolling

H =hammering

P =planishing

 

See Figure 10-13 for an example of a finish Symbol.