Currently I am involved in a project related to an expansion of an existing upstream facility .
we are in the process of connecting a new pump to an suction and discharge header of an existing pump which lies just adjacent.The exisiting pump nozzles are already vibrating and not really well designed piping.
we have suggested a dampening check valve to save our nozzles(how efective is this).ALso the suction and discharge lines are connected through relief valve lines.

Is there anything in particular to be considered when working on tie in systems?

Also in case of nozzles would there be a problem if the moments are unbalanced?? well all three under the allowables but still not a well balnced configuration.the API check is also ok