In piping model, a spectacle which is on a removable spool, is connected to an tube&shell heat exchanger nozzle directly.

My question is: is this configuration wrong? during maintenance, the removable spool including this spectacle is removed, how to prevent fluid inside piping come out?

even there is a valve before this spool, it still can not prevent fluid leakage completely.

Should we put the spectacle before the removable spool?

thanks for your reply.