How to Install PVC Pipe Under Kitchen Sink?

PVC plumbing pipes are better than galvanized and cast iron pipes in any and all given situations.

The pipes made of plastic polyvinyl chloride are generally used in drains, vents, and sinks.

They are lightweight, easy to install, and durable, making them an ideal choice for installation in the bathroom and kitchen.

Kitchen sinks generally have P-trap PVC pipes that have an S-shaped joint installed below the sink.

The particular design of the pipe prevents the backward flow of water. The pipe is connected to the drain pipe under the sink where water flows out.

In this blog post, you will learn how to install a PVC pipe under the kitchen sink.

Understanding the Basics

Types of Plumbing Pipes

When installing PVC pipes under your kitchen sink, it’s crucial to be familiar with the various kinds of plumbing pipes available. The two most common types of plastic pipes you may encounter are PVC and ABS.

Both of these materials have their advantages and disadvantages:

  • PVC (Polyvinyl Chloride): A popular choice for residential plumbing, PVC is known for its durability, affordability, and ease of installation. It’s also resistant to most chemicals and corrosion.
  • ABS (Acrylonitrile Butadiene Styrene): Similar to PVC, ABS is another type of plastic piping that’s commonly used. Although not as flexible as PVC, ABS tends to be more rigid and impact-resistant.

In addition to plastic pipes, older homes may still have metal pipes in their plumbing systems. However, these are not as common today due to their higher costs and susceptibility to corrosion.

Components of the Sink Drain

Understanding the basic components of the kitchen sink drain is essential to successfully installing PVC pipes under your sink. Here’s a brief overview of the key components you’ll need to familiarize yourself with:

  1. Sink Strainer / Basket Strainer: This is the piece that fits into the drain hole of the sink to catch food particles and prevent them from entering the drain. It also connects to the tailpiece for proper water flow.
  2. Tailpiece: The straight pipe that’s attached directly to the sink strainer. It extends vertically down from the sink and connects to the P-trap below.
  3. P-trap: The U-shaped portion of the drain pipe that traps water to prevent sewer gases from entering your home. It connects the tailpiece to the trap arm.
  4. Trap Arm: This is the horizontal pipe that connects the P-trap to the waste pipe in your home’s plumbing systems.
  5. Sink Trap: An alternative term for the P-trap. It serves the same purpose in preventing sewer gases from entering your home.

With a good understanding of the types of plumbing pipes and the basic components of a sink drain, you’ll be well-prepared to tackle the installation of PVC pipes under your kitchen sink.

Keep in mind the importance of assembling and connecting these components correctly to ensure a leak-free plumbing system.

Steps to Replace a PVC Pipe in the Kitchen

Tools Required

  • A PVC pipe
  • Sink connectors and drain traps
  • Adjustable wrench
  • A medium-size pipe wrench
  • Pipe cleaner
  • Bucket

Step 1. Measure the Size of the Drain Pipe

You must measure the size of the drain pipe to which you will connect the PVC pipe under the kitchen sink.

Taking exact measurements is important as even a small difference in size can result in a leakage.

Also, you should measure the size of the sink under the kitchen sink.

You must take accurate measurements using a measuring or plumber’s tape to know about the height between the sink and the drain hole.

The pipes must be of the same diameter as the ones you are replacing. The drain line that connects to the kitchen sink is not of a standard size.

The drain pipes in the kitchen are typically about 1 ½ inches in diameter.

The pipes in the kitchen are generally larger than the drain pipes in the bathroom.

The drain pipe in the kitchen is larger to prevent clogs that can occur due to food particles and grime getting stuck in the pipe.

If you are replacing a drain pipe, you should take a sample drain pipe to the hardware store. This will ensure that you buy the right size PVC pipe for the kitchen sink.

Step 2. Prepare for Installation of a New Pipe

You should prepare for the installation of the new pipe by placing a bucket under the sink.

You should also inform everyone that you will be replacing the sink pipe so that they don’t accidentally flood the area.

Remove the kitchen drain pipes one at a time. A recommended tip for easily removing the pipe is to cut the pipes right below the drain pipe.

The P-trap pipe can be easily removed without the use of a specialized tool.

To prevent the faucet from being used accidentally during the installation of the drainpipe, you should consider placing a bucket under the curved part of the pipe.

Step 3. Install the P-pipe

Wrap a plumber or Teflon tape around the threads of the drain pipe that you want to install under the kitchen sink.

You should then go ahead and fit the pipe into the sink drain. Use a slip nut for attaching the pipe under the sink.

Next, you should install the PVC pipe into the drain. Thread the pipe until you feel that it is secure. But avoid over-tightening the pipe.

You have to install two tailpipes for double drain sinks joined with a T-section.

Step 4. Connect the Tailpipe to P-Trap

The next step is to fit the sink trap on the tailpipe. You may have to use a sharpie for drawing a line onto the tailpipe in case space is not enough to fit the pipe.

Use a hacksaw for cutting the pipe so that it fits properly. Test the tailpipe before attaching it to the P-trap. You should go ahead and attach the pipe if it fits.

Step 5. Attach P-Trap to the Sink

The next step is to attach the P-trap to the sink. You should start by placing the washers into the slip nuts.

Make sure that you place washers in the slip nuts at the ends of the T-trap. The threads on the slip nuts must be facing the outside.

You must now tighten the T-traps by starting from the tailpipe and towards the main drain line. Avoid over-tightening of the threads.

This is important to prevent a crack in the plastic threads that can result in a leak. It is important to make sure that the pipes can be easily removed for cleaning when clogged.

Step 6: Test for Leaks

Once you have installed the PVC pipe under the kitchen sink, you should test it by turning on the sink faucet.

Consider filling the sink with water with the drain closed and then open the drain to let the water out with pressure.

Check the connections of the slip nuts for leakages as the water flows down the drain. In case you find a leakage at any of the joints, you must use a channel lock plier to gently tighten the slip nut.

But you should avoid over-tightening of the slip nuts as they can crack.

How to Select the Right PVC Pipe for the Kitchen Sink?

PVC pipes are available in different sizes and types that make them suitable for installation in most settings.

The pipes are better than the old cast iron pipes that were used in older buildings. Unlike the case with cast iron pipes, you don’t need to hot-solder the PVC pipe. Moreover, the pipe is also resistant to alkaline water.

When you head out to the store to buy a PVC pipe, you will find two different types of pipes including type 40 and type 80.

Type 40 pipes are cheaper that are suitable for residential settings. In contrast, type 80 pipes are suitable for industrial settings that are slightly more costly having a thicker wall.

However, the outside diameter of both the pipes is the same.

The two different PVC pipe standards have been developed by the American Society for Testing and materials.

The classification makes it easy to select the right type of pipes for a particular setting.

While the type 80 pipe is suitable for an industrial setting, you can also install it in your home kitchen if you can afford it.

Understanding the difference between the two pipes will let you know whether it is worth paying extra for a commercial PVC pipe.

Water Pressure

The water pressure rating of type 80 PVC pipes has a higher water pressure rating as compared to type 40 pipes.

The pipes have a thicker outer wall so they can withstand relatively higher pressure.

The water pressure of a pipe is measured in pounds per square inch (PSI). Type 80 pipes have a water pressure limit of about 630 PSI as compared to 450 PSI for type 80 pipes.

As a result, the pipes can better withstand alkaline water that runs down the kitchen sink.

Also read: What Causes Low Water Pressure in Kitchen Sink?

Pipe Thickness

Type 80 PVC pipe has a thicker outside wall as compared to the type 40 pipe.

Generally, type 80 pipe has a diameter of about 0.133 inches while type 40 has a diameter of about 0.179-inches.

An important point to remember is that the outside diameter of both the pipes is the same. So, the increased thickness of the type 80 pipe is from the inside.

While a thicker pipe can withstand more water pressure, it will have a lower flow rate even though the diameter of the pipe is the same.

Since the outside diameter of the type 80 pipe is the same as the type 40 PVC pipe, you can fit them together if necessary.

Color

Type 40 PVC pipe color is different from the type 80 pipe. The color of type 40 is typically white while the type 80 pipe is available in a grey color.

But in some stores, the colors may be different so it is important to ask about the type of the pipe before purchasing.

So, what type of pipe should you use for the kitchen sink?

Type 40 pipe will be suitable for home kitchens. The pipe is capable of a higher water flow rate that will be more than adequate for most home requirements.

You will save yourself money when you buy the type 40 PVC pipe for your home. The alternative type 80 pipe is suitable for use in industrial settings.

The pipes can withstand toxic water without developing any cracks.

But since the water flow rate of type 80 pipes is lower than the alternative, it is not suitable for use in residential settings.

When to Call a Professional Plumber

While installing PVC pipes under your kitchen sink may seem like a straightforward DIY project, certain situations may require assistance from a professional plumber.

Knowing when to call for help can save you time, effort, and potential damage to your plumbing system. Here are a few scenarios where seeking professional help is recommended instead of attempting the repair yourself:

  • Complex pipe layouts: If your kitchen sink has a complex pipe layout that is difficult to navigate or understand, it’s better to call a plumber with the necessary skill and experience to handle such situations.
  • Persistent leaks: If you’ve tried the DIY approach but still have persistent leaks or recurring issues, it’s time to consult a professional. They can identify and fix the problem quickly and efficiently.
  • Major pipe damage: In cases where your pipes are significantly damaged or corroded, simply replacing the PVC pipe may not be enough. A plumber can assess the situation and suggest the best course of action to repair or replace the affected sections.
  • Inadequate tools or experience: If you don’t possess the required tools or skill set to replace pipes under your kitchen sink, you might end up causing more harm than good. A plumber has access to the necessary tools and knowledge to complete the task efficiently.

To recap, consider calling a professional plumber if you encounter complex pipe layouts, persistent leaks, major pipe damage, or lack the necessary tools and experience.

Remember, it’s better to invest in professional help to avoid further complications and possibly costly repairs down the road.

Frequently Asked Questions

What are the steps for installing a PVC drain pipe for my kitchen sink?

  1. Turn off the water supply
  2. Remove the existing plumbing
  3. Measure and cut the new PVC pipes
  4. Assemble the pipe components
  5. Connect the new PVC pipe to the sink drain
  6. Secure and tighten the connections
  7. Turn the water supply back on and check for leaks

How do I connect a new PVC drain pipe to the existing plumbing under my kitchen sink?

To connect a new PVC pipe to your existing plumbing, you’ll need a compatible adapter. This allows you to connect the new PVC pipe to the old pipe material. Make sure to clean the pipes where they will be joined, apply a PVC primer, followed by PVC cement to create a secure connection.

Can you guide me through replacing old plumbing with a PVC pipe under the kitchen sink?

  1. Turn off the water supply
  2. Use a container to catch water from the drain pipes
  3. Identify the drain trap and remove it by loosening the nuts
  4. Cut the old pipes below the drain trap
  5. Unscrew the drain components and remove the old pipes
  6. Measure, cut, and assemble the new PVC pipes
  7. Reattach the drain trap and tighten all connections
  8. Turn the water supply back on and check for leaks

What is the proper way to seal PVC connections under a kitchen sink to prevent leaks?

To seal PVC connections, you should use pipe thread sealant on threaded connections and PVC cement for solvent-welded connections. Apply a thin layer of sealant on the threads of the male fitting, screw the connection pieces together, then wipe off excess sealant.

For solvent-welded connections, use PVC primer followed by PVC cement for a secure, leak-free bond.

What tools and materials are needed for installing a PVC pipe under a kitchen sink?

  • Pipe cutter
  • PVC pipes
  • PVC fittings (elbows, tees, coupling, etc.)
  • Pipe thread sealant
  • PVC primer
  • PVC cement
  • Adjustable wrench
  • Measuring tape
  • P-trap assembly
  • Protective gloves

How do you ensure a proper fit when installing a PVC pipe under a double kitchen sink?

To ensure a proper fit, measure the distance between the sink’s drain outlets and the wall’s drain stub-out. Cut the PVC pipes to the appropriate length. Dry-fit the PVC pipe components, making adjustments as needed.

Use a T-fitting or Y-fitting to join the drain pipes from both sinks, and ensure all the connections align properly before securing them with PVC primer and cement.

Conclusion

PVC pipes are the preferred pipes for installation in kitchen and bathroom skins. They are recommended since they are more durable and less costly than iron pipes.

These pipes can last for a long time without developing a crack. The pipes don’t rust or corrode similar to metal pipes making them the ideal choice.

But PVC pipes can get weak after decades of use resulting in a crack. The above tips will help you replace a cracked PVC pipe in the kitchen.

You can always call a plumber if you don’t have the time to replace the pipe in your kitchen.

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