A bending spring is a flexible metal spring used to provide the rigidity inside PVC conduit pipes necessary to bend them without distorting their original shape.
Bending springs is a fabrication procedure used to give springs new configurations. A wide range of industries, from the automotive to the building trades, rely on bent pipes. They are also employed in the design of instruments, automobile components, hydraulic systems, and pipes.
Pipe bending springs are metal springs used to steady the tube while bent by hand. They help the metal maintain its internal and external structure while being bent. As a result, the tubes are protected from stress and strain without distorting or creasing. Pipes with a diameter between 15mm and 25mm are the most common target for bending.
An efficient spring would be both sturdy and malleable. Therefore, you should only buy metal products and springs from reputable producers. Then, a complete and comprehensive guide on pipe bending springs is here.
Different types of internal and external springs are used for bending pipes. External pipe bending springs are more effective with smaller tubes, whereas internal springs can be used for bigger ones (15mm or less). When bending pipes with a spring, it's best to aim for a limit bend radius four times the tube's outside diameter.
Internal springs are flattened steel springs with a tapered end (to fit in the pipe) and an eye at the other. Because of the internal spring, the pipe wall does not collapse inwards as it's bent. Copper tubing with an exterior diameter between 12 and 22 mm often utilizes an internal bending spring (bigger springs are accessible but aren't recommended). Each size of pipe requires its unique spring to be bent.
Copper pipes with narrower inside diameters require external springs (6-10 mm external diameter). Again, they are formed from flattened steel, but this time with a "funnel" at every end to facilitate the insertion of the copper pipe into the spring's axis. Since the spring is around the pipe, it keeps the pipe's wall from bulging outward as it's bent. Each pipe size needs a corresponding spring, just like the exterior ones.
Unlike other tube-bending tools, these springs are quite simple in design. However, there are two distinguishing qualities about them.
Tapered end - it's used for internal bending, and its pointed end is inserted into the tube. Therefore, it needs to be diminutive to enter the tube. The pipe is inserted into the tapered end for external bending. As a result, there must be more room at the end for the pipe.
Ring end - Most springs used for bending pipes inside have a ring end, the tube section where the wire or string is fastened so that you can retrieve the spring after the tube has been deformed; for bending pipes on the outside, a ring end is unnecessary for the spring.
Finding the copper pipe you intend to bend before employing a pipe-bending spring is essential. When bending copper, longer tubes provide more leverage than smaller sections.
If the copper was sliced using a cutting tool, your bend might have a slight inward curve. In such a circumstance, you must debur the copper pipe edge. Uniform bending is made much easier with deburring.
You can employ a hacksaw to remove the tip of the tube or a reamer to make it bigger. Once the pipe is widened enough, you should feed the spring-tapered side into the bender first.
After the spring has been fully bent, it can be removed from the tube with less effort if it is oiled first. A good lube, you can even use olive oil on water pipes that carry drinking water. Do not forget to leave a piece of the spring from the outer tube so that you can retrieve it later.
The last step is to bend the copper tube against your knee and then retrieve it. Please do not pull back with too much force, as copper is a soft metal. You risk creasing the metal if you don't treat it with care.
The spring can be more easily retrieved if the tube is slightly overbent beyond the desired angle. Because of this, you may extract the spring using a tommy bar or screwdriver.
When looking for a pipe-bending spring manufacturer, there are several things to think about as mentioned here. There are metal suppliers with a wide variety of pipe bending springs, torsion springs, garage door springs, coil springs, extension springs, and more.