Figure 1. Close-up of magnetic-drive pump
with casing opened to show solid
thermoplastic casing, impeller and
Thermoplastics for Plants & Municipalities
Acids, Alkalies, Alum, Carbon slurries, Sodium hydroxide,
CHEM-GARD Horizontal Centrifugal Pump, SUMP-GARD Thermoplastic Vertical Pump
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Reprinted from POLLUTION ENGINEERING
Chemical plants and municipalities rely on
thermoplastic pumps for odor control, corrosion
resistance and reduced maintenance.
A recent study conducted by Pollution Engineering revealed that
approximately 40% of the respondents use nonmetallic pumps at their
facilities... even more significant, approximately 30% expected the
number to increase over the next three years. The primary reasons for
the current and anticipated use of plastic pumps were superior
corrosion and abrasion resistance and ease of maintenance when
compared with metals.
With the growing awareness of the significance of clean air and clean
water, there has been an increased use of nonmetallic pumps in a
variety of applications. These include scrubbing systems for odor
control, chemical feeding for enhanced coagulation, water recovery
projects, and neutralization of acidic or alkaline solutions as well as the
treatment of a wide range of liquid wastes or toxic fumes to satisfy
Consulting engineers and plant operating management play a major role
in the specification of pump designs as well as materials of
construction... more so than ever because thermoplastic pumps offer a
broad choice of chemically-inert formulations for the safe handling of
chemicals over the full pH range, and are now available for
temperatures to 300°F. In addition, the relatively low initial cost of
plastic pumps and their ready availability, in contrast to the rising cost
and extended delivery time of metals, have made this choice more
significant than ever. Added emphasis on environmentally-friendly and
low-maintenance products has further accelerated the demand for
sealless, magnetically-driven thermoplastic pumps. Here are two
Harpeth Valley Water Treatment facility changed from a manual system,
using granular hydrated lime, to an automated liquid caustic
neutralization treatment system to reduce costs and achieve
environmental benefits. According to their plant superintendent, a
critical part of the new system involved two Vanton sealless
magnetically-driven pumps to transfer the corrosive caustic (25%
sodium hydroxide) from the 12,500 gallon storage tanks to a 500-gallon
One reason for specifying sealless mag-drive pumps was to eliminate
any possibility for leakage. The engineers selected the Vanton pump
design because it was sealless, eliminating the need for mechanical
seals. The pump conformed with ANSI process pump specifications.
Vanton designs assure no metal components be in contact with the
fluid. The casing, casing cover and impeller were provided in
injection-molded, homogeneous polypropylene, and the inner portion
of the containment can of the mag-drive unit, the part in contact with the fluid, was made of polytetrafluoroethylene (PTFE).
As a result of the change from powdered lime to liquid caustic, there has
been noticeable improvement in environmental conditions, cleaner air
and happier employees and neighbors.
Beckman Coulter, Inc. is a major producer of clinical chemistry agents.
When they relocated their Puerto Rico plant to their plant in California,
they were determined to upgrade the sulfuric acid chemical feed system
to cope with changing environmental and workplace safety
requirements, and simultaneously secure higher productivity and
quality control. Their engineering department set these two pump
1. Eliminate any possibility of metallic contamination of the reagents; all
fluid contact components were to be made of chemically inert
polypropylene or one of the fluoropolymers.
2. Eliminate any possibility of fluid leakage through emissions or
spillage; the transfer and circulating pumps were to be the latest
sealless, magnetically-driven designs confirming to ANSI B73.1 process
In the Vanton CGM design, all fluid contact components are made of
solid, injection-molded virgin, homogeneous polypropylene. This is not
a lined pump. The inner magnet assembly is encapsulated in
polypropylene, and the large diameter stainless steel shaft is isolated
from the fluid by a PTFE Teflon assembly.
According to Jim Williams, Plant Engineering Manager, the Vanton
design eliminates the possibility of metal contamination of their high
quality product line, while reducing the chance of leakage so necessary
to meet proper health and safety standards.
Figure 3: Overview of compact installation showing six Vanton
Chem-Gard® Ansi end-suction polypropylene pumps recirculating acid
and alkaline solutions for an odor scrubbing system at a Florida waste
water treatment plant. The polypropylene material was perfectly suited
to handle the liquids, which had varying pH levels of 3-12. Pumps were
designed to deliver 650 GPM @ 38' TDH.
Figure 4: Two of eight Vanton PVC Sump-Gard® vertical pumps
employed at a water treatment plant in Arizona. Pumps were chosen
for their ability to handle different chemicals at varied concentrations
such as sulfuric acid, sodium hydroxide, alum, polymers and carbon
slurries. The average flow condition is 50 GPM @ 60' TDH.
Figure 5: Vanton Chem-Gard® magnetically-coupled sealless
polypropylene end suction centrifugal pumps transfer liquid caustic
from 12,500 gallon bulk storage tanks to 500 gallon day tanks at a water
treatment facility in Tennessee. These pumps are tied into a state of
the art computerized system, which eliminates manual labor, reduces
operating and reporting time and provides more accurate data. Service
conditions for these sealless mag-drive pumps are 55 GPM @ 30' TDH.
Figure 2: View of 12,500-gallon tank with
Vanton CGM magnetically-coupled
polypropylene pump for handling sodium
hydroxide at 55 gpm against a 0 foot TDH.
In the 1950, Vanton developed a revolutionary all-plastic pump for use in conjunction with the first heart-lung device. The design limited fluid contact to only two non-metallic parts: a plastic body block and a flexible liner. This was the birth of our Flex-I-Liner rotary pump. Its self-priming sealless design made it an industry standard for the handling of corrosive, abrasive and viscous fluids as well as those that must be transferred without contaminating the product. Vanton now offers the most comprehensive line of thermoplastic pumps in the industry.
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(+44) 01260 277040
Vanton Pumps (Europe) Ltd.
Unit 4, Royle Park
Congleton CW12 1JJ