Tube bending is an essential day-to-day operation in all kinds of industrial facilities. Despite its importance, tubing systems are often constructed by trial and error with little or no planning, which inevitably leads to wasted time and material and can even affect their efficiency and safety.
Fortunately, it doesn’t take any special training or complicated math to design and build a tubing system that’s optimized for the space. However, there are some important considerations when doing any kind of tube bending:
These all need to be incorporated into the design before you start.
In this post, we discuss some best practices when planning out a tubing system layout, including how to determine the distance between bends.
Before you start any tube bending, it’s important to plan how the system will be routed. Don’t skip this step—a little planning up front can save a lot of time, effort, and money.
Create a diagram laying out all the required directional changes, taking into account any obstacles in the space and any components that need to be installed. These will be accomplished either with bends or by connecting separate lengths of tubing with fittings, depending on the situation. The system should be as simple as possible while avoiding obstacles and remaining accessible for maintenance. A logical, efficient layout will make the system easier to maintain and minimize the risk of potential problems.
Planning out an efficient design up front doesn’t just reduce material costs and produce a more attractive design—it can improve the system’s performance and lifespan. Too many multi-radius bends produce turbulent flow, which can disrupt flow and produce vibrations that can lead to premature failure.
When planning the layout of a tubing system, there are several factors to consider. Here are some best practices to keep in mind:
The Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry Suggested Spacing for Supports
Tubing Diameter |
Tubing Diameter |
Distance between Clamps (ft.) |
Distance between Clamps (m) |
3/16 to 3/8 |
4 to 10 |
3 |
0.9 |
1/2 to 7/8 |
15 to 22 |
5 |
1.5 |
1 to 1 1/4 |
25 to 30 |
7 |
2.1 |
Maximum Horizontal Pipe Hanger and Support Spacing
Nominal Pipe or Tube Size (in) |
Nominal Pipe or Tube Size (mm) |
Standard Wt. Steel Pipe |
Copper Tube |
||||||
Water Service (ft) |
Water Service (m) |
Vapor Service (ft) |
Vapor Service (m) |
Water Service (ft) |
Water Service (m) |
Vapor Service (ft) |
Vapor Service (m) |
||
1/4 |
6 |
7 |
2.1 |
8 |
2.4 |
5 |
1.5 |
5 |
1.5 |
3/8 |
10 |
7 |
2.1 |
8 |
2.4 |
5 |
1.5 |
6 |
1.8 |
1/2 |
15 |
7 |
2.1 |
8 |
2.4 |
5 |
1.5 |
6 |
1.8 |
3/4 |
20 |
7 |
2.1 |
9 |
2.7 |
5 |
1.5 |
7 |
2.1 |
1 |
25 |
7 |
2.1 |
9 |
2.7 |
6 |
1.8 |
8 |
2.4 |
1 1/4 |
32 |
7 |
2.1 |
9 |
2.7 |
7 |
2.1 |
9 |
2.7 |
1 1/2 |
40 |
9 |
2.7 |
12 |
3.6 |
8 |
2.4 |
10 |
3.0 |
2 |
50 |
10 |
3.0 |
13 |
3.9 |
8 |
2.4 |
11 |
3.3 |
For more recommendations for tubing support, download Swagelok’s Tube Fitter's Manual. If you run into any issues during planning, contacting an expert may be your best option
Another critical factor when tube bending is the distance between bends or the amount of straight tube between bends. Why is the distance between bends important? Tube benders require a straight section of tube to clamp the workpiece securely during the bending operation. There must be a sufficient amount of tubing material for the tool to grip to prevent the tube from slipping during the operation. Having adequate distance between bends also allows bending with lower pressure, prolonging tool life.
Creating offset bends is a common operation in tube bending. Distance between bends is important here to ensure the offset provides the clearance needed to avoid an obstacle.
To determine the required distance between offset bends, first, use the offset angle (E) to determine the offset bend allowance (A) using the table below. Then, multiply the offset dimension (O) by the offset bend allowance (A) to get the offset distance (L).
L = O × A
Offset Bend Angle (E) |
Offset Bend Allowance (A) |
22.5° |
2.613 |
30° |
2.000 |
45° |
1.414 |
60° |
1.154 |
There’s a lot that goes into good tube bending—distance between bends is just one example of the factors you need to account for when planning and installing a tubing system. Edmonton Valve & Fitting supplies both tube benders and high-quality tubing to help you get the perfect bend every time. Need help achieving accurate bend angles or identifying defects? Our Swagelok-certified tube bending training can help your team perfect their technique and design, install, and maintain even the most complex tubing systems.