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']]rrrr stuffing Box Sealing

YES Is 1he Uquid Toxic?

No
Yes Is there Abrasive SlighlJy / ,._1 Cyclone SeparalDr
1,o .. 1,o
Conl~nt? "-I appropnale?

!
Yes Dues 1he Uquid ] Clean Rush
Crysl~lize? I from ex~ma] source
appropdal~?

!
No ,App~prial~? Yes contacts alrnusphem I
Is a Quench
When 1he Uquid
Sl~arn or Uquicl? is it Inflammable I
or Corrosive?
Yes I l~'J~
v f
Consider: Considel: Consider: Consider:
Double Seal & Single Inside Seal Single Inside Single Inside Sea] &
Barrier Ruid Rush and Quench or Outside Sea] Extema] Clean Rush

Figure 6.4: Seal selection chart

9 toxicity 9 rotational speed

9 operational frequency 9 previous field experience
At this point it is worthwhile to acknowledge the benefit of onsite
experience. If there is a history of a particular seal operating well in the
same service under similar conditions, then this should take precedence
over any other consideration.
It is also in the best interests of the end user to become sufficiently well
informed about mechanical seals and their ongoing development, in
order to be able to specify the particular seal needed in any application.
They can then require all pump suppliers to include that model in their
pricing. Alternatively, they can use a method of evaluation such as was
suggested in Chapter 5.

6.3.2 The seal faces
Most mechanical seals are designed with a rotating face in a softer
material wearing on a harder stationary face. For many years, the most
popular combination was the carbon rotating face running on a ceramic
stationary. These materials arc still in popular use, and have been
augmented by adding the option of stainless steel or even harder faces
in either tungsten carbide or silicon carbide. Detailed discussions with

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