Reverse rotation on pumps

[Midan]

If reverse rotation cannot be avoided (eg. NRV is passing), what would be the way to prevent Pumps mechanical seal damage?
In DGS for compressors there is the by-directional seals. How about the pumps?

 

[flexibox]

Most pump seals are bi-directional. They do not have directional grooves unless you have a gas seal. What type of seal do you have? Any drawings?

If it is multi spring normal seal should be ok. Are you experiencing seal failures?

 

[Midan]

Actually we are still in FEED stage and studying the possibility of seal failure due to reverse rotation.
Most of our selection is for plan 53B which I believe will have no issue as in all cases it is working on the clean barrier fluid, but for other seal plans like 11, 13 or 31. I need to get more information and experiences especially from operators and seal manufacturers.
I remember once I found pump vendor who supplies a reverse rotation protection device but I recall it has its problems and constrains.

 

[Pumpsonly]

As Flexibox put it, most seals now are using multi spring design and is bi-directional.
Single coil spring seals are uni-directional.

 

[flexibox]

As most seals are dual pressurised I think you should ensure the seals are suitable for reverse pressure conditions should it ever occur.