American Welding Society (AWS) D1. 1: The minimum distance between welds should be at least four times the thickness of the thinner part joined, but not less than 1 inch (25 mm).
The minimum distance between these two joints should be the one-time diameter of the pipe. So, if your pipe is 4″ NPS the distance should be 4″. If this is not possible, it should not be less than 1½”.
The gap may be as tight as 1/16 in. or up to 5/32 in. SMAW typically requires a tighter gap, while GMAW is more forgiving and allows a larger gap. The root gap should be large enough to allow the molten weld pool to fill it, but small enough so that the weld puddle doesn't fall through.
It should be remembered that welding over weld metal is actually a very common occurrence. Multi-pass welds after all are manufactured by welding over weld metal! There are also many accepted procedures in which welds overlap.
Weld from the bottom up.
Like building a house, you cannot start the bricks at the top. Weld metal is a liquid. When it goes in it needs support, that is why we need to always start at the bottom.
The overlap is a protrusion that occurs beyond the weld toe. Although overlap is more of a weld discontinuity, it's still classified as a defect. Mostly, overlap occurs in butt and fillet welds. When an overlap occurs, it means that the metal is not completely fused.
The distance between two weld joints should be 4 times the pipe wall thickness or one time the diameter of pipe but never closer than 1.5 inch. This is supposedly to prevent the overlap of HAZ of two joints.
In 20 to 22-gage sheet metal, your fit-up gap for MIG butt welding should be no less than the thickness of an unworn dime, but it doesn't hurt to be stingy with your money and generous with your fit-up gap.
In the as-welded condition, the distance between the edge of the base metal and the toe of the weld may be less than 1/16 in. (2 mm), provided the weld size is clearly verifiable.
2 Root openings (gap) between parts to be fillet welded shall not exceed 3/16 in., except in cases involving plates 3 in. or greater in thickness.
The rule of thumb assumes a double-sided fillet weld. Both legs of the fillet weld are of identical size. The weld is made for the entire length of the joint. The weld cannot be intermittent or less than full length.
Leg– The distance from the joint root to the toe of the weld.
On the other hand, the minimum edge distance (cmin) is defined as the minimum distance from the center of an anchor to a free-edge of the base material based on testing requirements of ACI 355.2/355.4.
Explanation: Minimum edge distance and end distance from centre of any hole to nearest edge of plate shall not be (i) less than 1.7 x hole diameter, in case of sheared or hand flame cut edge, (ii) less than 1.5 x hole diameter, in case of rolled, machine flame cut.
Minimum edge distance (distance between centre of the bolt hole to the plate edge) shall not be less than 1.25 times the nominal bolt diameter.
Arc weld gap distances are vitally important for the process of welding, not just for arc tig welding. It is important to consider the functions of each arc gap size before choosing what to use on any given job.
A general rule of thumb is you need 1 amp of power for every 0.001 inches of steel. Stainless needs 10-15 percent less current, and aluminum needs around 25 percent more. So, how many amps does it take to weld 3/8 steel? For 1/8-inch mild steel, which is 0.125-inch thick, 125 amps would be a good place to start.
Therefore, if you are a short distance from an arc, even a very short exposure to the arc flash can result in injury. As a result, personnel must be subject to adequate protection if they're closer than 10 metres from an arc flash. For example, you must be behind a Welding Curtain or wearing personal eye protection.
Weld sizes have an undersize tolerance allowable over about 10% of their length but in general the weld is considered a minimum.
The theoretical throat is the perpendicular distance between the root of the weld and the hypotenuse joining the two ends of the length. It is the shortest distance from the root to the face. Root: The parts to be joined that are nearest together. Root gap: It is the distance between the parts to be joined.
When it comes to welding, this other compound typically comes in the form of a metal such as iron oxide or aluminum oxide. These compounds can decrease the strength of a weld joint over time as they become wedged in between the base and filler metals.
The metallurgical, physical and chemical changes caused by the welding process affect the corrosion resistance of the weld. This leads to both the heat affected zone (HAZ) and the weld metal corroding faster or slower than the base metal.
If you do grind a perfect weld, yes it will make it weaker. If you just want to smooth it a little to make it look nicer, it will weaken it a little bit but should still have structural integrity.
EDGE DISTANCE: CRITICAL EDGE DISTANCE (Ccr or Cac) The least edge distance at which the allowable load capacity of an anchor is applicable without reductions.