conflicting sizes compression fittings dishwasher/ washing machine adaptor

Hi
I want to attach a dual spigot adaptor to accommodate two appliances I have a fitting but the white plastic compression nut on the fitting is too small to screw on to the trap assembly -the trap assembly nut size appears to be 55mm diameter and so is too big.
Is their a particular make that has this bigger size ? I can't seem to fin one on line that matches the existing trap
Thanks

 

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Please select a service and enter a location to continue...

Plumber / Gas Engineer Electrician Builder Decorator Builders' Merchant Plumbers' Merchant Tile Supplier Flooring Supplier
Start Search

Are you a trade or supplier? You can create your listing free at DIYnot Local