In my last article, we outlined the traditional reasons why people use welded pipe in applications, explained some of the difference between pipe and tubing, and briefly discussed tubing as it relates to safe installation and system operation. This week we will compare the cost of welded pipe versus tube systems.
Comparing Costs
When comparing welded pipe systems to tubing systems, it is important to develop a total installed costs for each option, including materials, labor, expendables, safety, environmental and other costs.
Material Costs
The cost of materials tube fittings and tubing are significantly higher than pipe fittings and pipe, especially in larger sizes. Comparing the bills-of-material for pipe and tube systems is not a simple one-to-one comparison. By bending tubing, the number of fittings to build a system can be significantly reduced. Tube benders can bend both small and large tubing to precise angles, eliminating the need route systems to the constraints of standard fitting angles. Not only does this affect the number of fittings, bending can also reduce the amount of tubing used to build the system.
Labor Costs
Material costs are offset through a reduction in labor hours, lower hourly labor costs, reductions in the number of fittings, and lower set up and site costs. Making tube fitting connections takes much less time than welding. Considering additional labor required for welding for fire watch, welder assistants, scaffloding and equipment setup. In addition, because are easy to installed, lower-paid unskilled laborers can be trained make leak-tight connections. Welders often recieve 50% higher hourly rate than other labor. Considering all of these factors using tube fittings can reduce labor costs by more than 75%.
Other Costs
In addition to the hourly wages for the welders, there are significant expenses incurred in establishing a weld site, preparing pipe and fitting for welding, maintaining safety and quality assurance. Some examples are:
- Obtaining fire permit for hot work
- Erecting scaffolding and provide ventilation
- “Sniffing” area, gas free, and weather protect
- Blanking flanges and nozzles
- Establishing fire watch
- Building fire box or tarps
- Draining, flushing, and drying lines
- Supply Weld consumables (purge gas and filler rod)
- Inspecting welds using weld X-ray or other non-destructive testing (NDT)
- Reworking damaged or misaligned spools
- Performing system soak, flush, or passivation
- Disposing HAZMAT materials
- Maintaining and monitoring flanges for leakage
Lost Revenue and the Welder Shortage
One of the things that keeps managers awake at night is delays are project delays. In many areas of the world and even in the United States, finding qualified welders can be challenging. The problem is so widespread, even Jay Leno has been talking about the shortage. The shortage can lead to production and project delays that cost thousand and even millions in lost revenue. Everybody knows that it take months to train a welder and years to gain the experience to make reliable welds in a wide range of situations. It only takes a few hours to train laborers to make leak-tight connections. This makes it easy to scale-up capablity as needed to meet deadlines.
Reducing Maintenance Costs
Tube systems can reduce maintenance costs. Tube fitting are remakable. They can be disassemble and reassemble many times. This makes tube system modifications and maintenance much easier than welded pipe systems. Cost savings have allow systems to use tubing and fittings to replace carbon steel with stainless steel fittings and tubing. Using stainless steel fittings and tubing can also reduce corrosion and improve system cleanliness.
Comments
Switching from welded systems to systems using tube fitting and tubing can reduce both system installation and maintenance costs, improve installation safety.
As usual, we welcome your comments and suggestions.