Customerally we find in many P&IDs bellow shown in pump suction line only for ambient water piping - why ? Is it for vibration isolation ?
If it is provided for construction dimensional mismatch or vibration isolation, why it is not provided at discharge side of pump ? Or, it is just a copy of the previous projects's P&ID, where it was provided for some other purpose, say for meeting allowable load at pump nozzle ?

What could be the possible reason ?

regards,

sam