Those pipes are horribly misaligned. That needs to be fixed.
To reinstall the gasket (yellow ring) first remove the pipe. Then you can install the gasket into the housing. After it's in place you can shove the pipe through the center. It helps if you coat the pipe in soapy water to lubricate it.
Can someone please advise . I have a small water feature that’s 2 parts. Bottom maybe 50l and the top part is maybe 30cm high. I want to pump water from the base about 5m away up a gradual less then 1/2 meter elevation and trickle out the top and water will run down a small stream back to the base. What pump size /head would I need ? Was thinking a 1000-2000l per hour pump Read More