The Necessary of 5 Points Check 2

[Rafael Dos Santos]

In Centrifugal pump, between bearing type or others say center hung type, is it necessary to do 5 points check if only 1 side of mechanical seal is under replacement or installation..?

 

[Artisi]

how many points would you suggest are done - 2.5?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[JJPellin]

I don't understand what you are referring to. If you don't give more details, you are unlikely to get any useful response.

Johnny Pellin

 

[Rafael Dos Santos]

there are some say that if only one side of mech seal is replaced, there is no need to do 5 points check on that side. It means, when installing a new one, no need to do 5 points checking, install it right away. Is it true? or it is compulsory to do 5 points check for installing mech seal whether is on one side or both sides?

 

[JJPellin]

I don't know what you mean by a five point check. But, I will assume. If you replace only one seal on a double-ended pump, is it acceptable to leave the other seal in place and not do bore and face run-out checks to verify that the shaft is centered in the seal chambers. This is my take. If I have no reason to believe I have a problem with the other seal, I will probably not disturb it. If I check the seal chamber of the seal I am replacing and I find out-of-spec conditions for face or bore run-out, then I would pull the other seal and check it. If everything checks out good on the seal that failed, I will probably not touch the other seal.

Johnny Pellin

 

[Rputvin]

Conversely if this is one seal and you're talking about just replacing one half of it? What type of seal is it?

My mind jumped to 5 data points to establish performance and/or check the pump to the curve - no flow (deadhead), min rated flow, design point or some mid-point/max eff., max rated or just shy, and runout off the end of the curve

 

[Rafael Dos Santos]

those 5 points check are:

1.) Radial deflection (0.005mm)
2.) Axial play/ Shaft End (0.1mm)
3.) Shaft run-out (0.05mm)
4.) Concentricity of bore (0.125mm)
5.) Squareness of face(0.125mm)

All checks must below those numbers (for axial play, its depend on type of bearings)

Let say outboard(O/B) or NDE side of seal is fail. So, we take out the seal and replace with new one. But, before installation, we normally do these 5 checks. So, back to my question, is it compulsory to do these checks if only 1 side of seal being install??

 

[Rafael Dos Santos]

Thank for replying my question.. really appreciate it