Pump Gland & Seal

[qazxsw]

For a centrifugal, overhung impeller, pump. What are the major different types of glands and seals? Also, what are the associated applications? I have a 70 gpm waste water application with high chlorides. Goulds is recommending Mechanical Seal (John Crane: Conventional-Single)and 316SS Flush for the gland.

 

[longeron]

That sounds pretty normal for what you've said about that application.

They probly recommended a single spring spring elastomer bellows seal. These are good in services with solids or slurries.

The 316SS is the material for the gland, not the flush. A seal flush is the use of a process fluid or an external fluid to cool the seal faces. If they did suggest a flush for a waste water pump it was most likely an 11 or 32. A Plan 11 is recirculation from discharge, drawing fluid from the discharge of the pump into the seal chamber. A Plan 32 is the use of an external fluid piped into the seal chamber that helps to cool the faces and could be used to exclude solids from the process or even the process fluid. Expect a close tolerance throat bushing in the pump to help with this.

There are many different kinds of seals. Your best bet for info are the mfgs web pages. John Crane, Flowserve, Chesterton, and Burgman all have good pages with lots of info. Or call a vendor and ask.

I'd ask for a cartridge seal. They may have quoted a component seal, individual pieces. Component seals require more time and effor to install, more can go wrong. Cartridge seals are already assembled and are usually tested as a unit before shipment. A cartridge seal takes a lot of guesswork out of installation. This is really worth it in the long run. Think about the time wasted repairing a pump and installing it just to find that the seal was installed wrong and having to pull the pump to fix that.