valve with minimum pressure drop

[SUTA]

We have a 6" carbon steel line which comes from "liquid Flash Drum" goes to "Vapour Recovery Unit". Maintaining minimum pressure drop along this line is critical for the VRU. So we are looking for a check valve with the lowest pressure drop in this line. I would put it in the 0.05 kPa area (very low).
Both drums upstream of the check valve are designed for 350 kPag so overpressure is not a concern if the VRU is suddenly down.

If a check valve cannot be provided in a reasonable range to the aforementioned pressure drop we can review challenging the efficacy of this valve.

Please let me know if you have any suggestion or know any product/manufacturer who can help us on this issue.
Right now my concern is to have an estimation of the end to end dimensinal at this stage.

Thanks in advance for your time & consideration,