How To Connect Different Types Of Waste Pipe (Video)

Compression fittings are versatile and reliable solutions for connecting waste pipes made from different materials, making them particularly useful in renovations or repairs involving mismatched systems. Here’s a guide to using compression fittings and some tips to ensure a secure connection.

Why Use Compression Fittings?

Most modern PVC waste systems use either solvent weld or push fit joints, but these cannot be mixed due to differences in plastic types. Additionally, older homes may have waste pipes made from unknown materials, metal, or even lead or copper. This is where compression fittings excel, as they are compatible with:

• All types of plastic waste pipes
• Metal waste pipes (e.g., copper or lead)

Compression fittings are available in 32mm and 40mm sizes, making them suitable for a variety of domestic waste systems.

How a Compression Fitting Works

Each compression fitting consists of three key components:

1. Compression Nut: Used to tighten and secure the fitting.
2. Plastic Washer: Helps position the pipe within the fitting.
3. Rubber Seal Washer: Creates a watertight connection by compressing against the pipe.

Step-by-Step Guide to Making a Joint Using Compression Fittings

1. Prepare the Pipe

   • Ensure the pipe ends are clean and free of debris.
   • Cut the pipe squarely using a pipe cutter or hacksaw, and remove any burrs with sandpaper or a deburring tool.

2. Assemble the Fitting

   • Slide the components onto the pipe in the following order:
     1. Compression Nut
     2. Plastic Washer
     3. Rubber Seal Washer (ensure the convex side faces the fitting).
   • Push the pipe into the fitting until it meets the internal stop.

3. Tighten the Fitting

   • Slide the components back into the fitting and hand-tighten the compression nut.
   • Use an adjustable wrench to tighten further, but avoid over-tightening, as this could damage the washer or pipe.
   • You’ll feel the washer start to “bite” into the pipe, ensuring a secure seal.

4. Test the Connection

   • Run water through the system and check for leaks. Tighten slightly more if necessary.

Tips for Using Compression Fittings

• Versatility: Compression fittings are ideal for joining pipes of different materials, including PVC, ABS, copper, and lead.
• Reusable: These fittings can be easily disassembled and reused, making them perfect for temporary connections or future adjustments.
• Proper Alignment: Ensure pipes are straight and fully inserted into the fitting to avoid leaks.
• Avoid Cross-Threading: When tightening the nut, ensure it threads smoothly to prevent damage.
• Use Silicone Lubricant: Applying a small amount of silicone lubricant to the rubber washer can help achieve a smoother seal.

Applications of Compression Fittings

• Repairs in older properties with unknown or mixed materials.
• Joining solvent weld and push fit systems where direct connections aren’t possible.
• Temporary plumbing setups that may require future adjustments.

Compression fittings provide a simple, effective way to connect various types of waste pipes, ensuring a leak-free and versatile plumbing solution. Whether you’re dealing with modern plastics or older metal pipes, these fittings are a must-have in your toolkit.

Please watch the video below for more details.