Large Scale Butterfly Valve

Large Scale Butterfly Valve
VAL
VES
SERI
ES120REMANUF
ACTURE
Townley provides a wide variety of valves to the mining industry and power plants. Townley has expertise in
complex castings and metal fabrication as well a broad elastomer material base. With 46 years of solving
abrasive wear problems, Townley engineers the best product for your application.
Why re-manufacture a valve?
By using a serviceable core, you are assured of perfect fit with existing piping and actuation. You also retain
some of your initial investment by using the same core.
Timing?
With proper pre-planning for expedited shipping and pre-purchasing of new materials, we can
usually meet your outage timetable for rebuild. If you do not have sufficient time however,
Townley can manufacture a new valve for you in time for your outage and remanufacture your
old valve for the next outage.
What if my existing valve is not a Townley Valve?
We excel at rebuilding the OEM’s of record like: Pratt, Dezurik, Fisher, Mosser, Media and Keystone.
What is a Townley re-manufactured valve?
We completely re-manufacture your OEM valve to better-than-new quality using
upgraded materials and methods at Townley. The upgraded finished valve becomes a
Townley Series 120 Valve.
The overview of our process, below, will describe the unique methods and materials
used to provide you with the most robust valve in the industry.
All new engineering
Our design group re-engineers your product to incorporate all the unique features and
standards of the Series 120 Valve, including: Solid through shaft, stainless steel pins,
neoprene to urethane disk seal and integrated flange gaskets.
Removal of old elastomer and metal preparation
After disassembling your old valve, we incinerate the core in an
approved furnace to ensure all elastomer is reduced to ash. The
metal core is then machined down to fresh metal providing a solid
platform and sufficient room for molding of our Towniprene™
Urethane lining. We also remove about ¼” from each flange face to
make room for our integral Towniprene™ gasket. Old bushings are
also removed and new one pressed in place.
Enhancements to core
Expanded metal strips are welded to the valve body I.D. to ensure mechanical
lock-in of the Towniprene™ lining, followed by metal shot blasting the whole core,
which cleans and creates the proper surface profile for secure bonding. Prior to
any molding of Towniprene™ the whole core is coated with a proprietary adhesion
promoter to assure chemical bonding of the urethane to the metal core.
MJH Jan 2009
Molding of Towniprene™ lining
The prepared valve body is aligned and secured to an “inner mold” which defines the flange gaskets and I.D.
seal of the body. All ports are plugged to prevent leakage of urethane during pouring.
The assembly is then heated in a large oven at controlled temperatures until the metal
stabilizes at the proper pre-pour temperature.
This activates the adhesion promoter and the heated assembly will
ensure good flow characteristics of the liquid urethane. When
removed from the oven, the assembly is leveled and the
Towniprene™ is poured into the mold cavity. The assembly is then rolled back into the
oven for a final cure. After a sufficient cure cycle and cool down, the molds are removed
from the assembly and except for minor trimming, the body and Towniprene™ seal is
complete. The urethane is now a continuous molded seal from both flange gaskets
throughout the I.D. seal for the disk.
Shaft preparation
New 17-4 stainless steel shafts are used in our Series 120
valves. We are one of the few using a solid shaft through the
disk. Experience has shown this to be the most robust method of securing
the disk providing overall strength and perfect alignment. This can’t be said for the
traditional two part shafts, featured with other competitive valves. When isolating millions of
gallons of water or slurry, which would your safety department and confined space workers prefer?
Disk fabrication and neoprene lining
Townley fabricates new disks from welded carbon steel incorporating a stainless steel shaft tube for all
remanufactured valves to ensure maximum integrity of the complete final assembly. After metal shot blasting
for surface profiling, the metal is coated with a primer and hand applied
neoprene. The neoprene sheets are hand applied to completely
encapsulate the new “convex lens” style metal disk. A dimensionally
precise ring is affixed to the O.D. of the disk to ensure exact finished
dimensions of the neoprene after the high temperature vulcanization
process.
Valve assembly
The body and disk are brought together and the shaft is pressed through both joining
them. Stainless steel taper pins used to secure the disk to the shaft. This alleviates
any galvanic corrosion effects, which is the primary failure mode of other OEM valves.
Towniprene™ pin covers are bolted to the taper pins without adhesive patches. This
allows for periodic inspections without the need to grind and re-patch by maintenance
workers, no solvents, no vapors, no adhesives, which create a whole new set of
potential problems.
Final assembly and testing
If specified by the customer, new operators are installed and
tested by our factory trained personnel. The finished valve is
pressure tested to the customer’s specifications to ensure leak
free service. With the two different durometer ratings of neoprene
and urethane, an excellent compression fit is assured with easy
opening and closing because of the non-galling characteristics of
urethane and neoprene used together as a sealing interface.
Better than new
The customer now has a new valve with features and function far better that the original
with a clear value advantage for each customer.
MJH Jan 2009