Hose flow capacity

[RichD1]

Can anyone tell me what the difference in flow rate is between a 32mm pipe and a 38mm one. Pipes are coming to and from a pump to the external filter. Overall pipe length from pump to filter is about 5 metres. Max head is about 800mm. Current pump is rated at 3000l/min.

 

[combatwombat]

Howdy. Not quite enough info to know for sure. You can work out your dynamic head using these charts (will have to convert pipe size to metric): https://www.engineeringtoolbox.com/pvc-pipes-friction-loss-d_802.html

Would need to add those losses to your static head and then reference the curve for your pump to know what rate will be.