Original Vanton polypropylene duplex pump
with Hypalon flexible liner. This pump
has been under test for 1-½ years,
handling a variety of corrosive fluids.
These 35 Flex-i-Liner® Duplex Teflon
Pumps with Viton flexible liners are
scheduled to replace the troublesome
diaphragm pumps at Boeing's Wichita,
Kansas facility. They will be handling
a variety of acids, caustics and
the Boeing Company
Acid salts, Caustic solutions, Chromic acid, Hydrochloric
FLEX-I-LINER Sealless Self-Priming Peristaltic Pumps
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Reprinted from PLANT SERVICES
By Charles M. Boyles, C.P.E., Editor-in-Chief
Upgraded system for handling corrosives improves
safety and reduces waste
The building has the latest in environmental controls, which provide a
safer workplace for employees while increasing productivity and
protecting the environment.
One of the reasons the Boeing Company has become the largest
aerospace firm in the United States is its published commitment to cut
waste and boost productivity with less time at the lowest possible cost.
Coupled with this high quality and low cost drive is Boeing's emphasis
on changing manufacturing processes to improve worker safety and
reduce the environmental impact of its operations.
When the huge — more than a million square feet — manufacturing
process facility in Wichita, Kansas was completed in September 1991, it
was hailed as one of the largest and most technologically advanced
facilities of its kind in the world.
It is truly a state-of-the-art metal finishing and painting facility. There,
critical parts for every Boeing commercial jet liner undergo a variety of
corrosion-inhibiting processes to extend service life.
According to Boeing's Health and Safety Administrator, Chris Frederick,
construction of the manufacturing process facility allowed Boeing to
consolidate many of these chemical processes in a single building. The
building has the latest in environmental controls, which provide a safer
workplace for employees while increasing productivity and protecting
the environment. Specific emphasis was placed on incorporating an
automated chemical addition system in the facility design. The system
reduces direct operator exposure during tank filling and periodic
chemical additions. Also, it has a sophisticated chemical milling
The recovery system regenerates sodium hydroxide used for chemical
milling and removes the dissolved aluminum from the process. These
products are recovered and recycled as part of Boeing's environmental
program. Boeing is determined to comply with and exceed EPA
regulations. Existing chemical addition practices associated with
charging and maintaining pH control in metal finishing tanks were
considered impractical for this modern facility.
A better way
In the past, many of the chemicals used were received in powdered
form and were handled by production process mechanical cranes. This
approach was relatively slow. The powdered chemicals did not
dissolve readily in the finishing tanks. Also, the employees were subject
to possible chemical exposure during the transfer of powders that had
hardened in drums.
Boeing conducted a thorough examination of the equipment design and
the potential hazards for employees. From this study, Boeing decided
to standardize on the use of liquid formulated metal finishing chemicals
instead of powdered.
The new liquid chemical addition system uses bulk loads of the
chemicals for initial tank charging. The new system has dedicated
pipelines to transfer the chemicals to specific tanks safely. This system
completely eliminated any manual contact with the chemicals.
For the daily or "on demand" chemical additions, Boeing engineers
specified 350-gallon portable tanks with flow-controlled chemical
metering pumps. Thirty-six chemical metering stations were
established to transfer chemicals safely from the portable tanks to the
appropriate metal finishing tank.
The corrosive, hazardous and toxic chemicals — nitric, sulfuric,
phosphoric, hydrochloric, hydrofluoric, chromic acids, acid salts,
caustic solutions and solvents — required the closed piping systems for
The variety of chemicals Boeing handled dictated the use of non-metallic
pumps. Non-metallic pumps ensure resistance to corrosion and avoid
the potential for metallic contamination in process solutions.
Boeing engineers also wanted to test several different types of positive
displacement chemical metering pumps for comparative evaluation.
Initial studies resulted in the decision to install electric and air operated
diaphragm type pumps.
Although the new liquid handling system was a decided improvement
over the powder drums, there were problems with the diaphragm
pumps. They were relatively noisy and required pulsation dampers to
ensure even flow of chemical additions. This resulted in costly
In keeping with Boeing's ongoing quality improvement program, the
maintenance department decided to test a non-metallic peristaltic
metering pump that was in use for handling a wide range of corrosive
The pump had to meet some basic requirements. It had to be sealless
and self-priming. Fluid contact components had to be non-metallic.
Also, the pump had to preclude the danger of external leakage or
fugitive emissions — in keeping with Boeing's environmental
Boeing engineers selected a pump with a polypropylene casing — body
block — and a flexible liner made of Hypalon™ — a chloro-sulphonated
polyethylene elastomer. They also specified that the pump be supplied
with a variable speed motor and speed controller for controlled
According to Boeing's Maintenance Supervisor, Bert Montgomery, and
Maintenance Project Engineer, Lawrence Hole, the test pump has been
in service for 1-½ years without any problems.
As a result of the successful test, the project engineers wrote a detailed
specification for a similar unit with duplex pumps. The pumps are
constructed of a single group of non-metallic materials that are inert to
the corrosive chemicals and solvents handled by the portable tanks.
Boeing engineers decided on this combination of pump materials:
pump casing — reinforced Teflon™, flexible liner — Viton™, expansion
rings — Delrin™, and unpigmented polypropylene piping. This design
offers complete interchangeability of pumps and spare parts. This
translates into low maintenance inventory. In keeping with Boeing
engineers' thoroughness, they also specified an organic stabilized
grease for lubrication.
Boeing's manufacturing process facility is now replacing its diaphragm
chemical metering pumps with self-contained metering pumps at 35
chemical metering stations. Also, Boeing is experimenting with a
pumping system for its soluble machine coolant recycling center.
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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Vanton Pumps (Europe) Ltd.
Unit 4, Royle Park
Congleton CW12 1JJ