In any giant installation of air-operated double-diaphragm
(AODD) pumps, a comparatively tiny portion of pumps contribute to more than
average maintenance prices, usually because of misapplication. Since the bulk
of AODD pump applications involve no over easy method fluid transfer, several
pumps are mobile and transferred from one location to a different.
An operator could attribute a “good” pump installation to
the pump, and not the installation. The operator could transfer the “good” pump
to a brand new installation and shortly once, the “good” pump becomes a major
maintenance downside. Worse still, the high maintenance could become routine,
leading to substantial prices, in relation to the pump.
Since most AODD pump applications ar either
easy transfer or filter press feed, following a number of necessary steps will
avoid pricey mistakes.
1. Piping
System properties, like piping, will contribute considerably
to AODD pump application problems, particularly on the suction side of the
pump. Most diaphragm pumps have dry elevate capability within the vary of
fifteen to twenty feet. One way to think of this is the literal lift
capabilities of the pump. Another way is to think about this specification
because the most resistance pipe loss that a specific pump will handle. In
different words, if a pump features a dry elevate capability of fifteen feet,
then it cannot tolerate over half-dozen.5 pounds per square inch (psi) of pipe
loss when priming the pump with a particular process fluid. Consider the
consistence of standard latex house paint, that is or so one,500 centipoise
(cps). When transferred through a 5-foot-long, 1-inch line at 20 gallons per
minute (gpm), the frictional losses are around 34 psi, which is well beyond the
capabilities of any AODD pump. Increasing the inner diameter of the suction
line to one.5 inches reduces the pipe loss to 6 psi, well within the
capabilities of most AODD pumps. One of the best supplier of Air Operated Double Diaphram pump is
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2. Chemical Compatibility
Although a straightforward step in AODD pump specification,
chemical compatibility is often overlooked when moving pumps within a facility.
A common mistake is to assume that a more expensive material affords better
chemical compatibility. Consider an 80 percent solution of sodium hydroxide
(NaOH). Commonly offered compatibility charts list olefin propene diene
chemical compound (EPDM) rubber as A-rated and therefore the costlier
fluroelastomer (FKM) as D-rated. Another example is isopropyl acetate. In the
case of this process fluid, the less expensive polypropylene is often listed as
A-rated, while the more expensive polyvinylidene fluoride (PVDF) is commonly
listed as D-rated. The pump manufacturer ought to give charts or tools to help
with this method.
3. Temperature
Two concerns should be taken into consideration once considering
temperature and AODD pumps: temperature limits of the pump’s material of
construction and extra limitations because of method fluids. AODD pump dealers can usually
publish temperature limitations of the pump’s numerous materials of
construction. These temperature limits are solely based on mechanical stress,
thus other considerations must be taken into account when deciding on the
limitations of a particular pump application. Certain method fluids will cut
back the utmost temperature limit even more. Consider an application that seeks
to transfer 10 to 75 percent of sulfuric acid (H2SO4) with a
polytetrafluoroethylene (PTFE)-lined polypropylene pump. Common compatibility
tables list both PTFE and polypropylene as A-rated for H2SO4 (in certain
concentrations).
However, several compatibility tables list seventy two F as
Associate in Nursing higher limit for plastic. Thus, ought to the temperature
of the method fluid (H2SO4) exceed seventy two F, the material of the pump
should be changed to a more appropriate material. In this case, PVDF is a
suitable alternative to polypropylene.
4. Abrasives
Abrasives will have a prejudicial result in several pump
applications. Several steps can be taken to mitigate the effects of abrasion.
First, a material’s physical properties should be considered. Thermoplastic
elastomers have abrasive resistance properties. In sensible applications, an
abrasive resistant elastomer that is B-rated for a particular process fluid may
outlast an elastomer that is A-rated but has poor abrasive resistance. Second,
consider fluid velocity. The relationship between a fluid’s velocity and the
abrasive effect on a pump’s material of construction is not linear. A small
increase in fluid velocity can have a disproportionate impact on the abrasive
wear of components. While pumping abrasive liquids, transfer the liquid at the
slowest flow possible. In severe instances, consider oversizing the pump so
liquid moves slower.
5. Air Issues
Due to the adiabatic enlargement concerned in operative a
pump on compressed gas, one must consider moisture, both in the process and
ambient since the temperature of the exhaust airis well below the freezing
point of water.Guarantee that the pump is operated on clear, dry atmosphere,
and in situations where this is not possible, be knowledgeable of muffler
blinding. Consider a pump’s placement within the facility once evaluating air
issues—i.e., is the pump close to an open door?
Make sure the airline supplied to the pump is adequately
sized. An undersized airline can result in chattering, underperformance or
unwanted noises. Consult with the AODD Pump Manufacturer on the
suggested airline size.
6. Torque
Develop a preventative maintenance program to torsion all
external hardware to the recommendations, notably once exploitation plastic
pumps.
Follow the manufacturer’s recommendations for frequency and
technique.
These items are often overlooked. Transfer applications are
simple, and the basics are often ignored or assumed to play an insignificant
role. When in doubt, consult the manufacturer, who should be able to offer
valuable advice for implementation. FOR MORE INFORMATION visit us ANTLIAENGINEERINGWORKS
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