Warwick Duo Sink Drain Pipe

Good Evening

On my 2011 Warwick Duo the rigid drain pipe from the kitchen sink emerges through a panel underneath the sink and at one point there is an oval plastic cover. I woould like to place a small container on the floor and detach this cover in order to clean the pipes. Is this possible and is there an easy way to take the cover off without breaking it. I assume tthat there is either a plastic clip or lug that would have to freed first in order to allow thus to happen. Help please.

Many thanks

Malcolm

The "plastic cover"  is the bowl for a trap, presumably to prevent any unpleasant smells from the waste tank getting into the van. It's straightforward to unscrew. But I doubt whether the pipe needs cleaning, the slow draining from the sink is a "feature" of the Warwick Duo and is probably caused by an airlock in the above mentioned trap.

Many thanks for the reply. I will have a look tomorrow to see if I can remove the cover to gain access to the trap. The sink does drain extremely slowly so, hopefully, I can improve matters and clear any airlock.