Plan 1 seal, flushless?

[nucleareng78]

I've been having a hard time understanding terminology regarding mechanical seals. Difference between flush water and seal water?

I have a pump that will be processing seawater and am planning to go with a John Crane Type 1 seal. The question is whether or not we need external flush water (from the domesitic water supply) or if it can be a flushless seal.

My understanding of flushless is where you use the process fluid as the flush/seal water? Please correct me if I'm wrong or if there an online resource out there that may be able to help me out.

Thanks!

 

[flexibox]

I would use API Plan 11 but make sure you use a Monel spring to prevent stress corrosion cracking. Flushing with domestic water will be expensive. Ask your local JC representative for their advice too!

 

[Pumpsonly]

It depends on what type of pump you are using. Some ANSI 73.1 pump has a tapered seal chamber and is design for self flushing. Best to check with pump vendor.

 

[nucleareng78]

I checked with them and they usually use a Flushless John Crane Type 1 (Carbon/TC) with a Mondel gland and collar.

Another newbie question. Since we are using a mechanical seal, there is no Packing Gland or Stuffing Box? Or does this stuff just come standard from the pump manufacturer?

Sorry for the rookie questions, trying to learn.

 

[flexibox]

The mechanical seal fits into the stuffing box. The seal replaces the packing.

 

[nucleareng78]

Thanks for the clarification, I'm not sure why I couldn't comprehend that!