transfer issues with new pump at freezer vessle

[wsharv]

we had an ancient York IT pump, which finally failed. It was under our freezer vessel and used to transfer ammonia coming back from the freezer and into the system. we replumbed and replaced with a viking lq4924A pump that we had on site. in a week we have blown out two shaft seals. Is this pump too big for the job? is it creating excessive back pressure? transferring too quickly? would be delighted if someone could give me some ideas on how to fix this issue. thanks

[seanf]

You probably already have it, but;
https://cdn.brandfolder.io/FMWE0LVS/at/7rppt2bhvbrhpvq92h8734/TSM_1467.pdf

and
https://cdn.brandfolder.io/FMWE0LVS/...g/Sec_1467.pdf

Is it ammonia or the oil thats leaking?
Shaft alignment?