Leaking Mechanical Seal

[tfpd109]

Ok, I did a search, and came up empty, so if there is a thread on this, them I suppose this is a repost We have a 1250gpm Waterous pump that the mechanical seals just started leaking on. The truck is 12 years old and this is the first time we've had a problem with this. The leak is about a drop about every 5-10 seconds, not running. (yeah, you want to know what it does when it runs, and I didn't do it) I think I know the answer to my own question, but would you recommend getting the truck in to have the seals replaced? My opinion is get it in and see whats going on with it. Thanks for any feedback Guys and Gals!

[lvwrench]

Try Waterous pump co. 651-450-5038, fax 651-450-5090 Steve Toren at cell 612-963-5158 or e-mail www.waterousco.com. I use the old packing style waterous. Never cared for mechanical seals due to the way people operate here.

[GreggGeske]

The seal(s) are worn out and need to be replaced. It is not an emergency or anything. There is no adjustment to be done. The pump will still draft but if it is leaking while it is sitting in the station and your tank to pump valve is left open or leaks your tank will go empty. If you have any questions you can e-mail me.

[Firefighter1244]

Our Quint has a 1500 gpm Waterous in it....Mechanical Seals....it's 7 years old and the seals were just replaced about 3 months ago. We didn't put mechanical seals in our pumper we received in October....went back to packings!!!!!

[saylesvillefd35]

We replaced the mechanical seal on the 1500 gpm Waterous in our old quint. The old seals lasted 15 years without a drop until it finally wore out. The cost to replace them was fairly reasonable and we picked the truck up the next day. It was a no brainer specing a mechanical seal in our new quint.

[Stuart]

You should do a vacuum test immediately. Will your pump pull and hold the vacuum required to draft? If it passes, then a small leak is nothing more than a nuisance. If you can't pump the rated capacity of the pump, it's time to at least get the seal(s) replaced.

[FWDbuff]

The seal(s) are worn out and need to be replaced. It is not an emergency or anything. There is no adjustment to be done. The pump will still draft but if it is leaking while it is sitting in the station and your tank to pump valve is left open or leaks your tank will go empty. If you have any questions you can e-mail me.

Hey Gregg- a question. Many of the old timers have always taught me that a slow leak is a good thing- keeps the seals wet and cool. Can you confirm or deny this? THANKS.

[Catch22]

Hey Gregg- a question. Many of the old timers have always taught me that a slow leak is a good thing- keeps the seals wet and cool. Can you confirm or deny this? THANKS.

That's when you're talking about packing. You need to allow a few drops/minute through to keep the shaft cool. With mechanical seals, they're designed to seal off the water, no leaks. If you're leaking through the seal, it's a sign of wear and time to start planning for replacement. What sucks about that is that you have to expose the end of the impellor shaft to replace it where packing you didn't have to tear much apart.

[GreggGeske]

FWDBuff, Sorry I did not respond earlier, I was at FDIC all week. Catch22 is correct; packing should not leak any less than 6-10 drops per minute. The mechanical seal is cooled with water internally between the carbon rotating ring and the silicon carbide stationary ring. The advantages of mechanical seals are that they do not require adjusting and do not leak (until they fail). The disadvantages are that once the fail the outboard bearing and the transmission have to come off to replace them. If you can get 5-7 years out of them you are doing pretty good. I have an 89 tower that still has the original seals in it and a 96 pumper tanker. I replaced the seals on my 96 pumper after 7 years. The advantage of packing is that it can be repacked without taking the pump apart. Both packing and mechanical seals are susceptible to damage by overheating. Packing can be more forgiving if you are in an area with more corrosive water.

[tfpd109]

Thanks for all your input. FYI, we have the problem fixed. Be safe out there!