mechanical seal 1

[tomato5]

following api 682, if the seal support system for an application is deternmined to be 23/52, have you physically installed such an arrangement, and did it do its job satisfactorily?

thank you

 

[JJPellin]

We probably have a dozen pumps with this combination. I believe that all of them work well. It looks rather complex. But I am not aware of any problems with this system.

Johnny Pellin

 

[CaracasEC]

We have also such arrangement on our ethylene cracker plan...

 

[GaTechTheron]

Question: How hot is the service? Can you not use cooling coils in the P52 pot to soak up heat from the back of the inboard seal? I, personally, would not depend on this set up unless you have a separate pump circulating the liquid in the P23 line as opposed to relying on the pumping ring. Pumping rings work great for a standard P52 pot and barrier fluid...

If you must stick to this, there are some things to look out for:

1) Are you using a pumping ring to circulate the fluid through the heat exchanger? If so, the heat exchanger needs to be very near the seal so that the pumping ring can circulate fluid appropriately.

2) Consult with the seal MFG to determine height of heat exchanger above centerline of the shaft.

3) Make sure the lines running to the seal are vented before start up and sloped as to never have a horizontal section or area where air can become trapped. Pumping rings don't work well on air. (Neither do liquid seals)

4) Avoid any system designs that can cause restriction. (90 deg elbows, small lines, pipe, anything but full bore ball valves, high pressure drop across heat exchanger).

5) Consider fouling factor of heat exchanger over time.

6) Maintain tight clearance of the throat bushing.

7) Make sure interconnecting lines between the pot and the seal are all going to and from the correct locations on the seal gland and the seal pump.

8) Check viscosity at minimum temperature, and ensure this is not too high as to clog the seal flush lines and heat exchanger.