How to install insinkerator waste pipe?

[jgoldman158]

Hello Bunnings Community!

I am trying to install a replacement insinkerator and need to connect the straight waste pipe into the existing waste array. 

Any advice on how to connect the attachment as seen in the professional photo into the existing waste?

Thank you!

New connection to attach to existing waste systemOld insinkerator waste connection

[EricL]

Hello @jgoldman158 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about the installation of your In-Sink-Erator.

Just a friendly reminder that any plumbing work must be carried out by a licensed plumber for safety and compliance.

It's highly probable that the plumber will use a device called a Caroma 50mm Garbage Disposal Trap Adaptor With Dishwasher Connection. This add on is usually placed on top of your sink trap and the entire assembly is lowered in order to accommodate this device. Please note that it is an involved installation, and I don't recommend it as a first D.I.Y project. 

If you have any other questions we can help with, please let us know.

Eric

[jgoldman158]

Hey @EricL thanks so much for your reply. Couldn’t I use a compression fitting to connect the new waste pipe to the existing? Obviously cutting to size as needed. 
For example:

Holman 40mm PVC Compression Fitting / Coupling Repair
https://www.bunnings.com.au/applinks_p3140447

Do you think that would work?

The install otherwise looks straightforward so just trying to solve for the waste pipe.

Thank you!

[EricL]

Hi @jgoldman158 

It is technically possible to install your In-Sink-Erator with standard PVC parts. There is no need to use a compression fitting, it will require you to use a PVC "T" fitting and the ends will need a male and female adapter. The critical part is that the In-Sink-Erator pipe must fit into the "T" piece that you'll be using. I propose bringing it with you so that you can test it on the PVC parts at the store. There are reduction couplings you can use just in case your sink trap happens to be 50mm and your In-Sink-Erator is only 40mm. 

Please note that the white pipe fittings are for swimming pool high pressure fittings only, please do not use those parts. You're only using the grey PVC fittings that is meant for drain waste and vent.

If you have any other questions we can help with, please let us know.

Eric

[jgoldman158]

Hey @EricL thanks so much for the response. 

I’m really confused why a T fitting is needed? I am trying to connect the new waste pipe for the replacement insinkerstor to the existing elbow connection that goes into the rest of the waste system. All the pipes are 40mm and all are white (if that matters). 

What is the third element that requires the T connection? 

[EricL]

Hello @jgoldman158 

My apologies, I was under the impression that the bottom picture was a sample only and not your actual plumbing situation. You might be able to get away with using a compression fitting. I suggest bringing the pipe with you to test at the store to make sure it fits. I've placed an image below just to show you how the In-Sink-Erator is usually fitted into the trap set.

If you need further assistance, please let us know.

Eric