Calculating parameters in welding is a great way to keep track of work output and facilitate payment and improvements. In welding, mathematics is important to calculate connections for metal frames and angles for joints and welds. Weld inches are also essential, so how do you calculate weld inches?
You calculate weld inches by multiplying the diameter of the pipe by the number of joints or number of meters welded. Weld inches find application in pipe welding, and it helps project managers and supervisors make estimates for productivity and payment.
This article looks into weld length and how you calculate weld inches. I also discuss the purpose of inch diameter and how to measure welding productivity.
What Is the Weld Length?
Welding is all about measurements and calculations, and professional welders understand the importance of mathematics in the welding process. Good mathematical skills in welders enable them to increase their productivity, work on complicated projects, and complete more tasks.
Except for plug and spot welds, each weld has a length component. The weld length may be some portion of the joint or the entire length of the joint. Symbols show weld lengths on design drawings.
When a weld is supposed to span the entire length of the joint, the welding symbol does not need to include the length component. The welding symbol indicates the joint that needs the weld, and the entire length of that joint is welded.
The designer places the required length to the right of the weld symbol—to show that they do not require the weld length to extend the complete joint length—and the welding symbol points to the part of the joint that needs the weld.
For fillet welds, the American Welding Society A2.4 says that the drawing does not have to specify the length if the length is full length.
How Do You Calculate Weld Inches?
Weld inches refers to Inch Diameter or Diameter inch (ID or DI) and Inch Meter (IM), and they are taken as units for measuring piping job loads and other functions.
DI of (phi) denotes inch diameter, and it is a measure of the amount of welding labor required—quantum of the job—for Welding, Radiography, MT, TOFD, DPI, TFM, AUT, PAUT tests. NDT agency also uses it as units for payment purposes.
IM usually defines the quantum insulation (besides Meter cube), Piping Erection jobs, and it serves as a payment purpose with Main/Sub-Constructors of Construction. The formulas to calculate them are:
- IM = Pipe Diameter (in inches) x Number of Meters
If the pipe diameter is 10 inches and there are 30 meters, the IM = 300 Inch-meter.
- DI = Pipe Diameter (in inches) x Number of joints
If the pipe diameter is 10 inches and there are five joints, the DI = 50 Dia-Inch
SpoolFab is a software that can calculate Diameter Inch automatically. It allows you to customize the calculation according to your company’s preferred method for excluding and allowing for differences in pipe wall thickness and materials.
Only shop welds are included on fabrication drawings, and only field welds (except those marked with Charge Code = no charge) are included on installation drawings. The app also excludes hidden welds from the calculation of diameter inches.
The diameter of the pipe is the same as the number of welds per hour, and you can charge an hourly rate of pipeline joints. One hundred forty (140) inches of weld per hour is what an average welder can complete.
What Is the Purpose of Inch Diameter?
Inch diameter helps both welders and supervisors in many ways, including:
- Planning human resources for a given number of joints per pipe DI within a specific time frame.
- Helping the Planning Engineer to estimate a completion target for the job.
- To find out the piping erection load and monitor the progress of the piping work.
- Calculating the cost of welders per day
- Helping the Estimation Engineer to quote rates for the job.
Knowing the inch diameter makes welding jobs more manageable, and you should get familiar with it.
How to Measure Welding Productivity?
Manufacturing managers, welders, accountants, and shop supervisors all care about calculating or measuring productivity. Without the proper knowledge to assess productivity, it might be challenging to track how it affects profitability, and it affects it a great deal.
Productivity in the construction industry comprises the performance of the production process: equipment, materials, and workforce. An equation mostly used to assess productivity in this industry is Productivity = Man hours (MH) ÷ Output Quantity.
Besides this formula, here are other ways to measure productivity in welding:
- Measuring the deposition rate productivity works best for heavy welding applications like multi-pass welds.
- Travel speed is a better measuring stick for single-pass, autogenous, or sheet metal applications, and it is also the first category for improving welding productivity. Wire diameter and wire feed speed are some variables of travel speed to consider.
- The operating factor or arc-on-time is another category to measure welding productivity. Data from some studies show some welders were only welding for 20 to 35 percent of the time, using semiautomatic or manual welding modes.
- The presence or absence of standardized welding procedures is also a measure of productivity. If all welders on the team work according to their whims, there will be no consistency in the company produces.
- Filler wire used—wire length or weight.
- The units of production per day or week, or quarter, based on the manufacturing volumes.
- Rework, or scrap rates, also indicate productivity. The more time spent scrapping and reworking, welds diminish the time spent producing new works.
You can improve welding productivity by reducing the amount of rework welding and over-welding, ensuring procedure compliance, supporting personnel who need training.
You can also take steps to minimize the number of non-welding tasks done by welders (like cleaning and heating) that don’t add value to the product. Doing this allows them to focus on the more productive operations of welding
No investment is too significant to improve productivity because great productivity encourages efficiency, high-quality products, and increases the company’s profitability.
