Lasdrop Shaft Seal Failure

How do others have their seals plumbed? Tee lines or crossovers? Perhaps most others have a single port so you just tee them together?

Lew - what brand seals are you running?

My previous seals were plumbed the same way and I never had an issue either. I'm already seeing signs that the new port seal is failing again. I've got something weird happening here. And I don't have faith in these Lasdrop seals. Although the starboard side has been fine so I'm not really sure what's going on here; yet. You can the port seal bleeding some rust and some black carbon coming off of it. You can't tell from the picture but it is discolored like the other one was that failed.
It pisses me off that I've had to haul and replace seals, especially given they provided zero guidance on how to plumb these **** things. Here's current photos taken yesterday of both seals.

.

We pulled the hose off the seal coming from the engine and fired them up and there is significant flow going to the seal. We also verified no plugs, obstructions or kinks in the lines. To your point d_meister, we could be getting some type of air pocket or weird pressure differential through that crossover line that is causing an issue for the port seal. What I can't understand though is when we replaced the seal a few months ago we went out and trialed at cruise speed for well over an hour and monitored both seal with a temp gun. There was less than 1 degree difference between them the whole time.

I was just looking at the Tides online. They even show them plumbed with a crossover line right online. My first glance through their catalog and I did not see the size I need which is 2.75" shaft and 5.00" stern tube.

The PSS seals look like they have only one port on each seal. Are you saying you have Tee fitting in each supply line going to the other side?

I had some flow testing done today. The straight supply to the seal from one engine is about 2 gpm. With one engine running, the supply to the opposite side seal is much, much less. So it sounds like this crossover plumbing is NFG. The only thing I still don't understand is why the port seal is failing. Since replacing it I have never ran on just the Stbd engine. I have run either both engines while cruising and did about 5 hrs. of trolling but that was with the port engine running. So why didn't the stbd side seal fail then and not the port side?

I don’t think the tube is clogged. We checked it when we replaced the seal and it was clear. But that being said I’m not taking anything for granted so we are working on a flow test to verify we have clear flow through both sides.
The rust is odd to me too. Lasdrop claims when the stainless overheats it losses some of its anti-corrosive properties. Now I’m no metallurgist but in my line of work we weld stainless every day. The heat from welding (much greater than a seal getting hot) doesn’t alter stainless properties and make it rust.

Thanks but I’m not going to add flanges to my shaft logs or buy seals that are not readily available and serviceable in the U.S. There are easier options for me should I decide to change make and model.

Much appreciated!