Attaching leak box to dished head

[Saki20]

Hello team,

I want to add an leak box (cylindrical) on top of existing top head. the three nozzles on top head having leaking problem. hence need to be covered by a box. while designing this leak box in PV elite it is not getting fixed on top of head as shown below. i tried changing the datum options. but still not fixed. cylinder element will attach to flat surface only ? is there is any other way to add this box on top of head..?

Thanks
Saki