Edmonton Valve & Fitting Blog

Weekly posts for northern and central Alberta engineers, plant operators, and buyers.

5 Ways Tubing Beats Piping in Small-Bore Applications

by Katie Dennis, on Wed, Jul 17, 2013 @ 10:07 AM

Tubing is simpler, lighter, easier to install, and has fewer potential leak points; it also costs less when you factor in tools, labour, and maintenance

 

swagelok tubing

Compared to a piping system of comparable strength, tubing systems need fewer connections, have better strength to weight ratio, are leak-tight, and are easier to maintain.

See below for an example and download the Small Bore Tubing Solutions PDF »

Historically, piping was the way to get fluid from Point A to Point B for any system more than an inch in diameter. It's even written into a lot of specifications. But once you've tried tubing for small-bore applications, it's hard to go back. Tubing is simpler, safer, and faster.

Comparing tools, labour, maintenance needed

Consider the tools needed for building a typical threaded piping project: Pipe stands, dies, cutting oils, sealants, and PTFE tape or sealant. Then there is assembly, testing, disassembly, rework, and reassembly. For a welding job, you need a qualified welder and welding equipment. Depending on the job, you may need weld permits, air tests, firebox, tacking, weld quenching, finish welding, purging, passivation, and inspections.

To make the same system out of tubing is much less complex. Aside from the tubing and fittings, you need only a tube bender, a deburring tool and a wrench. On a big job, a hydraulic swaging unit might come in handy instead of the wrench. With a little instruction, anyone in the plant can assemble and install Swagelok tube fittings correctly the first time, and we do offer classes if you are looking for extra support and training.

Piping system example

Let's look at a sample installation. In the first illustration, you can see several drawbacks. The tightening of the pipe into the elbows depends on the strength of the installer. The elbows may end up being over tightened, which can damage the threads and cause leakage. Or they could be under tightened in order to line up properly and, again, result in leakage.

swagelok tubing

Additionally, this system has eleven potential leak points. Once a piping system is installed, removal of any component requires sequential disassembly. That, in turn, may cause movement of other threaded connections and cause leaks. As environmental regulations continue to get stricter, leaks become more than just nuisances and maintenance items. They can mean fines and downtime while they are being fixed.

The same system, with tubing

Now let's look at the same system made with tubing. First you'll notice the simplicity. All you need is a single length of tubing and two tube fittings. As with pipe, the tubing must be cut and deburred. However, to reach from Point A to Point B, the tubing is simply bent. No extra fittings are required. A bend in the tubing creates less turbulence and pressure drop than a pipe elbow.

To connect the fittings, they are pulled up a one and a quarter turns manually or with the hydraulic swaging unit to create a leak-tight seal. There are only four potential leak points. Tube fittings also allow easy access to system components without sequential disassembly. 

swagelok tubing

Built with tubing, this installation is also much lighter than pipe. There is less weight to store, lift and install.

Our example uses 90-degree bends, but the advantage of tubing only grows when offsets and odd angles come into play. The tube can be bent exactly as needed, saving space and improving flow.

By itself, tubing costs more than the equivalent amount of pipe. But when you add the cost of tools and labor, then factor in how much maintenance each system needs, tubing comes out ahead. In most applications when our customers have deviated from pipe and replaced with tubing they never go back to pipe applications. 

So if you are still using pipe, why not take a look at the advantages of tubing?

Topics:TubingFittings

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