How to Bend an ABS Pipe

What You'll Need
Filling Medium (Sand, Salt or Metal Coil)
Hairdryer or Flameless Hot Gas Torch
Suitable Plywood Jigs

One of the prime advantages of using ABS pipes is the plastics’ ability to reform its shape. These plastic pressure pipes are commonly used for both underground and above ground conveyance of waste water, drinking water, food stuff, gases, slurries and compressed air. ABS pipes can be bent within a longer radius to suit household needs. Follow these steps to bend an ABS pipe yourself instead of hiring a professional to do the job for you, thus saving excess costs.

Step 1- Take Measurements 

Take measurements to estimate the angle you might want the pipe to bend to. Plastic pipes are able to deform without breaking due to their ability to absorb stress. However, their ability to absorb stress is dependent on the force applied, which means that pipes can’t bend beyond a certain angle. Therefore, for more angular bends larger pipes should be used where as smaller pipes suffice smaller bends.

Step 2- Choose a Suitable Plywood Jig

After determining the approximate angle you want to bend your pipe to, choose plywood jigs easily available in the market with that angle. Plywood jigs provide the same angle you want your pipe to bend to and can be used as a benchmark to ensure you do not exceed that extent during bending.

Step 3- Fill the Pipe with Sand

Use an appropriate filling medium that suits your need to fill in the pipe, such as sand, that ensures an even distribution of heat and provides the pipe with an internal medium that prevents it from collapsing when bent. Enclose the pipe from both ends to prevent air pockets that prevent or hinder an even distribution of heat during the heating stage. 

Step 4- Apply Heat and Bend Simultaneously

Heating the pipe can be tricky because plastic can easily melt if even slightly over-heated and ABS has a melting point around 175 F, which is easily reachable. Therefore, only appropriate amount of heat should be provided evenly to the entire pipe. For heating purpose you can use a hairdryer or a flameless hot gas torch. Heat the pipe evenly while simultaneously applying gentle pressure to bend it. The best way to recognize the maximum temperature your pipe can sustain is to use a spare small piece of pipe as sample and heat it while adjusting the heat-knob on hair dryer or flame torch. This will give you an idea of how long it takes the pipe to soften and the appropriate knob position to stick to. Use the help of the plywood jig while bending to ensure that you do not exceed the angle that you intend to reach. Make sure that you apply pressure at the right places so that the bend is produced at the point where you intend it to.

Step 5- Remove Sand and Rinse

Adjust the pipe into the fitting to determine whether you have reached the right angle. Repeat the process of heating the pipe if adjustments in the bend are required. Try to bend the pipe with minimum heating as re-heating the pipe again and again distort its shape and leave it brittle. Open the pipe and let the sand flush out once you reach the required angle. Rinse the pipe with warm water to remove any traces of sand so it is clean.