Model 550 Mechanical Seal by ltq40826


									                                 QUARTERLY NEWSLETTER                        APRIL 2006

                                           SEAL SENSE
Advanced Sealing International

                                    The ASI Model 550
                                    Heavy Duty Slurry Seal
                                    also in this issue...

                                    Seal Customization for Specific Applications
                                    Employee Profile: Peggy Van Veckhoven
                                    ASI Success Story: History of the Model 550
                                    ASI Distributors: Top 5 in 2005
                                    Spring Seal School: Highlights and Pics
                                                                VOLUME 1, NUMBER 2
Distributor News
Quarter 1, 2006

ASI Spring Seal
         The spring 2006 seal
school was held March 6th and
7th in Baton Rouge. It was an
unqualified success! Attendees
came from all over the country
and as far away as Trinidad,
down in the Caribbean. Once
again interest in ASI seals and
how and why seals work was
foremost on everyone’s mind.
After experiencing both class-
room and “hands-on” training,
everyone had a better under-
standing about our seals and
mechanical sealing. ASI will
hold another seal school later
this year and we encourage all
interested to sign up and “im-
prove your sales with convinc-
ing product knowledge.”
For information about future seal schools, contact an ASI sales representative
at (225) 272-2155 or visit our website at

Top Distributors in 2005
         Once again, we are very proud of our distributors’ hard work in
2005, as many of our top accounts increased their sales efforts to higher
levels. ASI is committed to helping our distributors to become even more
successful in 2006 and looks forward to the many sales opportunities the
upcoming year will bring.
          1.   AGI Industries      New Orleans, Louisiana
          2.   Equipment Pro       Bloomsdale, Missouri
          3.   Fluid Concepts      Baton Rouge, Louisiana
          4.   Valley Equipment    Jonesborough, Tennessee
          5.   Sealing Solutions   Chattanooga, Tennessee
                                         ASI Model 550
                              Heavy Duty Slurry Seal: In Detail

          The Model 550 is ASI’s double slurry seal, designed for slurries with
up to 80% solids. It is a custom-fitted seal that completely fills the pump
stuffing box, preventing the product from entering the box while providing an
increased amount of barrier fluid around the seal components.
          The Model 550 is built to handle heavy slurries that tend to dewater in
the stuffing box or plate out onto the seal components. Because the seal
completely fills the stuffing box, the
product does not come into contact
with any metal seal components. This
design eliminates the need for special
metallurgy as only the two inboard seal
faces and o-rings (in the bottom of
the stuffing box) will see product. The
standard inboard face combination
for the seal is siliconized graphite
against silicon carbide; however, other
combinations are available. Coupled
with the appropriate o-ring material,
all metal components in the seal are
constructed of 316ss. The inboard
rotary unit is also available with a circulation device or “pumper” feature.
          The Model 550 operates as a double seal, utilizing a single component
seal driven by a single cartridge seal. The inboard seal arrangement is com-
posed of an o-ring mounted stationary face, which is pressed into the bottom
of the stuffing box. A component style rotary seal is then mated against the
stationary face. Next, a cartridge seal is mounted on to the stuffing box, and
engages the component seal with a set a pins. The spring compression for the
inboard seal is set when the gland bolts are tightened. The outboard cartridge
seal is then used to drive the inboard component seal.
          A pressurized barrier fluid system is required for operation of this
seal. The barrier fluid is piped into the inlet port in the BOTTOM of the seal
gland, and exits out of the flush inlet (lantern ring inlet) located on the TOP of
the pump stuffing box (to vent any entrained air).
          As with any pump specific seal, exact equipment dimensions are re-
quired to properly fit the seal and, unfortunately, the Model 550 may not adapt
to every piece of equipment. However, for standard pumps, the Model 550
provides as an economic alternative to conventional double seals, not only for
slurries, but for any application requiring special metallurgy.
Technical Notes:
Seal Customization for Specific Applications

         Although seal companies rarely
admit it, constructing an economically-
feasible, universal-style mechanical seal
that is ideally suited for all applications
and sealing environments is a somewhat
impossible task.
         ASI realizes that attempting to create a completely “bulletproof” seal
is impractical, so we incorporate a certain amount of adaptability or room for
customization into our standard seal designs. This flexibility allows us to
construct our seals with materials suited to a wide application range while
providing the capacity to fine-tune our products for specialized applications.
To assist our distributors, we’ve assembled a list of some common “tweaks”
or seal enhancements that may, under certain conditions, significantly improve
seal performance. In fact, in some cases, these minor adjustments can be the
difference between sealing success and failure.

Light Hydrocarbons
         The face balance in ASI’s seals has been calculated to deliver optimal
closure without excess wear for the majority of all sealable applications.
However, certain products, primarily those with a specific gravity of 0.7 or
less, may require more closing force to the seal faces than our standard balance
provides. Typically, these products, especially light hydrocarbons, require a
“non-standard” face balance to prevent these lighter fluids from escaping.
Under these circumstances, ASI recalculates the seal balance to accommodate
the application requirements, then “reprofiles” our standard faces accordingly.
Face reprofiling is a fairly simple procedure with a minimal charge that does
not usually alter standard delivery when presented at the time of a seal order.

High/Fluctuating Operating Temperatures
          On occasion, single or unpressurized double seals running in applica-
tions with extreme temperature fluctuations may experience intermittent leak-
age (especially when maximum temperatures reach over 300o F). This leakage
can often be attributed to distortion occurring to the stationary unit as the
standard 316ss holder expands and contracts (with the temperature fluctua-
tions) at a rate that is different than the stationary face insert. Normally, after
the temperature stabilizes, the stationary unit will “lap” itself back flat, which
in turn, causes the leakage to cease. This process, however, can be somewhat
lengthy for tungsten and silicon carbide stationary faces. Additionally, some
applications may not have a stabilization period or may require zero leakage.
Under these conditions, we recommend the use of a CEA (Controlled Expan-
sion Alloy) holder. A CEA stationary holder is built from metal that is compat-
ible with both the application’s chemical requirements as well as the stationary
face’s thermal expansion rate. What this means is that the face and holder heat
up and cool down simultaneously, which will limit any face distortion that
may occur. ASI also recommends our CEA holder for applications with con-
stant temperatures in excess of 300o F. Not only does this holder limit distor-
tion caused by the differing thermal expansion rates, it also prevents the face
insert from slipping or loosening in the stationary holder in extreme tempera-
ture conditions. Basically, if the seal application requires high temperature o-
rings, it probably requires a CEA holder as well. CEA holders are stocked,
standard delivery-time items for our universal seals; however, there is an addi-
tional cost (varying by size and model) for this holder. In cases where cost is
a primary issue or when distortion is excessive, the ASI Models 730 and 525,
which have monolithic seal faces (i.e., no stationary holder), may be a more
viable option for the application than the Model 585.

Sticky or High Viscosity Fluids
         For universal style seals, ASI generally prefers the superior chemical
compatibility and application versatility of silicon carbide as our standard ro-
tary face material. Viscous or “sticky” products, however, present a few is-
sues with silicon carbide material. When a pump is stopped and these prod-
ucts are allowed to thicken or harden, they often “glue” the seal faces together
or, at a minimum, impede their rotation. Once the pump is restarted, the
breakaway torque required to free the faces occasionally damages the silicon
carbide rotary face. In such applications, ASI recommends the use of a tung-
sten carbide rotary face (once product compatibility has been established).
The added tensile strength of the tungsten carbide material provides superior
breakage resistance, especially in intermittent services where the pump is fre-
quently restarted. For the most part, ASI stocks tungsten carbide in ANSI
sizes and supplies it at a slightly added cost. TC is considered “our standard”
rotary face for our larger, high-motion style seals and is usually stocked and
available at no additional cost for these models.

In Our Next Issue...
Seal Customization for Hot Oils
ASI Success Story
The Model 550: A History of Outstanding Performance

         This success story actually began in 1987,
when a local distributor presented ASI with the
challenge of sealing a problem application that
had been plaguing a nearby plant. The application
product, phosphoric acid, operated at various
temperatures and concentrations, including a
highly concentrated form called “super-
phosphoric acid.” The variances in
the operating parameters yielded a
product consistency that ranged
from a thick syrup to solid crystals.
Additionally, the product’s highly
corrosive nature normally required the
use of expensive alloy metals in any mechanical
seal provided. At the time, the plant was unhappy with the high cost of its
present seal and the poor performance that it provided.
         ASI decided that the only way to eliminate the need for exotic metal
alloys was to fill the entire stuffing box with the seal, preventing the product
from coming in contact with any metal. To achieve the ideal “inboard” seal
face combination at an economic price, we coupled our component-style Model
SD-1 (with its standard siliconized graphite face material) and a silicon car-
bide o-ring mount. We then completed the “outboard” end of the double seal
by “locking” the SD-1 unit to our Model 525, utilizing its cartridge-mounting
to drive and set the inboard seal. This new seal arrangement resulted in what
we now call our Model 550.
         For over 18 years, the Model 550 has provided unsurpassed perfor-
mance in its original application, and is still used today by the same plant. And,
over time, ASI has found the Model 550 ideally suited for many other slurry
applications. Additionally, it has been sealing various forms of HTH paste and
other bleaching materials, as well as higher concentration caustic products.
More recently, we have discovered how well it lends itself to hazardous waste
applications. For several plants, the 550 (supplied with a tungsten carbide
“pumper” version of the SD-1) has been the only seal to overcome the large
abrasives, varying chemicals and occasional dry-run scenarios typically found
in hazardous waste service.
         As for this success story, ASI believes this is just the beginning; we
are confident there will be many more applications and many more years of
successful seal performance by the Model 550.
                        Employee Spotlight:
                                              Peggy Van Veckhoven

                For this issue, our
spotlight falls on Peggy Van
Veckhoven, ASI’s superintendent
of seal assembly operations.
Peggy began her tenure with ASI
in November 1993 as an assembly
technician. Working her way
along, she quickly moved into the
repair service area and eventually
became the repair operations
manager before assuming her
present duties. It is, perhaps, this
extensive knowledge in all facets
of both seal assembly and seal repair that provides her with the necessary
skills to perform her job so well. At present, her crew is the most efficient and
productive group of technicians that has ever worked for ASI. This crew’s
superior competence level hasn’t evolved by accident; Peggy’s steady hand,
people skills and knowledge of ASI mechanical seals make our assembly
operations’ performance second to none.
          Peggy is married to Clay Van Veckhoven, a maintenance supervisor
with the East Baton Rouge Parish Department of Public Works. She has a
daughter, Sarah, who (you guessed it) also works for ASI as an assembly
technician. They live close to the small town of Livingston, where they enjoy
a country lifestyle in a beautiful rural setting. For leisure, Peggy and Clay
spend their time camping and fishing, as well as maintaining the grounds on
their property.
          As part of her job duties, Peggy oversees the training and manage-
ment of all assembly personnel. She also coordinates quality inspections,
purchasing activities, inventory management, shipping/receiving, equipment
maintenance, warehousing and housekeeping. Additionally, it should be noted
that her department’s safety record over the last five years is superlative.
          Several people and operations are involved in preparing just one seal
to ship out the door, and Peggy orchestrates the entire process. So, next time
you send in an order or rush a seal through the system, appreciate the timely
service and flawless quality that Peggy and her assembly crew deliver on a
daily basis. And, if you are visiting ASI, make it a point to say hello to Peggy
and all of her talented employees. Of course, don’t plan on spending too much
time; our assembly department is a very busy place.

To top