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Now we’ve
established the importance of pumps in our lives and in particular,
the pool industry, allow me to focus in on pumps used for chemical
delivery. Although these pumps are properly called
displacement pumps (remember) both reciprocating diaphragm, and
rotary peristaltic, in the industry, are often called: Chlorinators,
chemical feeders, injectors, metering pumps, diaphragm pumps, chem-feeds,
and the rotary peristaltic is often referred to as a tube, or
squeeze tube pump.
Now that we’ve
covered some of the history, I’d like to share some of what I’ve
picked up over the years. Working for a well-known chlorinator
manufacture for nearly forty-five years has taught me quite a lot.
Some of what I have learned may be valuable to you, a pool industry
professional. I would like to clear up some myths, or assumptions
I’ve been asked about from time to time.
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Chlorinators
should be trouble free.
Of all your pool equipment, the chlorinator probable will require
the most attention. The reason is simple, you are dealing with
more than a mechanical pump, such as; water chemistry, bather load,
water temperature, and chlorine. When you put them all
together there is more involved than a chlorinator. If any of
the above items are neglected your job will soon become more
complicated.
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Chlorine is on
its way out.
Let’s be honest about this. This is a case where the good
definitely outweighs the not so good. Don’t even try to
imagine our lives without chlorine as a disinfectant.
Alternative forms of disinfectants will continue to play a larger
roll in our industry, and that is a good thing. Make no
mistake chlorine is still the disinfectant of choice in our
industry, it simply works well and the cost benefit isn’t worth
arguing.
Most pool
professionals have their favorite type of chlorine. As a
manufacturer, I do too. Let’s go over some selections.
Liquid chlorine (sodium Hypo), is usually purchased at your favorite
distributor, dealer or chemical company, some regions the chemical
is delivered on a route basis. This industrial strength
chlorine runs anywhere from 9% to 15% active chlorine. The chlorine
you purchase at the super market is considerably weaker about 4%
chlorine. Sodium hypo, or liquid chlorine is the chemical of
choice for most mechanical chlorinators, some will argue that point,
but for the most part its liquid chlorine. The problems with
liquid chlorine are; it is heavy, cumbersome, and transporting it
can be hazardous. Liquid chlorine weakens over time. Dry
or powder chlorine also has its advantages, and disadvantages.
It is certainly easier to store, and transport. Some kinds
also have a built in stabilizer so your Ph rarely needs adjusting,
but now you have to be careful of too much accumulation of
stabilizer, which will certainly cause eye irritation, etc.
Some of the challenges are obvious; you have to mix a slurry so it
can be pumped. The amount of undissolved solids will over time
foul check valves. Peristaltic pumps are indicated if you
choose to pump a chlorine slurry. Peristaltic pumps easily
handle chlorine slurries. With either the diaphragm or peristaltic
chlorinator, avoid trichlor, this very potent form of chlorine is
simply just too corrosive for mechanical feeders and is not
recommended.
Some tips on
maximizing the performance of your mechanical chlorinator
(diaphragm, or peristaltic style)
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Keep
variables to a minimum. Such as, chlorine strength, type
of chlorine used, and setting on chlorinator feed rate.
Example; if you keep the chlorine strength consistent, as the bather
load increases, and the days are warmer, you’ll need to increase the
amount of chlorine to be feed. On a peristaltic pump, adjust the on
time up (pump longer), with a diaphragm pump increase the cam
setting, or pulse rate. If you tamper with chlorine strength
(usually a problem with slurries), and chlorinator feed rate, you
will just drive yourself crazy. Minimize your variables.
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Avoid
running chemical container dry. Although the pump may not be
mechanically harmed, pumping air will cause the valves to build up a
residue of dried chlorine (salt), after detailing the check valves
several times it should become clear running the chlorinator dry
simply creates more work.
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Purge air
out of the pump tubing. After changing out chemical containers
make sure, the pump is primed and most air is purged out of the pump
head. The system just works better when most of the air (gasses) are
purged form the lines (eye protection please).
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Regular
maintenance. At least every six months inspect, and if
necessary, replace your diaphragm. Also, inspect the top and
bottom valves; clean or replace. If you are using a peristaltic
feeder, change tubes out regularly. Also keep your eye on the
roller assembly; the rollers do require periodic lubrication.
Rollers that are frozen, not rolling correctly will dramatically
shorten the life of your pump tube.
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Keep spare
liquid ends
(assembled pump head kits) handy, as we all know Murphy’s Law,
“Problems usually occur at the most inopportune times”, it’s far
easier to replace a diaphragm and pump head complete with valves
(usually just 4 screws) than detailing every o-ring and ball seat.
Using peristaltic pumps? Keep pump tubes and roller
assemblies on hand. Time is money.
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Inspect your
foot valve strainer – At
least quarterly, or a frequently as necessary.
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Avoid trying
to prime against lime pressure - Chemical Injectors are easy to
prime when the discharge (pressure) line is removed or vented.
After the pump is primed re-attach the discharge line to the top
pump head valve, or close the vent relief (eye protection cannot be
over stated).
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Always wear eye protection
when working on chemical injectors or when changing out containers,
or adding chemical.
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Want to
change chemical brands? Avoid changing chemical brands
without researching the compatibility on your injector pumps.
I know we are pressed for time, this is not the time to cut corners,
find out if the new chemical is compatible with your pump before you
switch, at least ask a colleague who has had some experience with
the product.
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A
flow indicator is a
fantastic diagnostic tool - Installed on the suction tubing of
your chlorinator (flow indicator) is an outstanding diagnostic tool,
at a glance you can see if the pump is working properly. No
indication means your chlorinator isn’t pumping. If the ball
indicator is bouncing violently it may indicate too much back
pressure from a plugged
injection fitting.
The indicator is simply a window to monitor your system.
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Chemical
controllers are of growing importance to our industry. Most
controllers work well with automatic chlorinators; stick with the
industry leaders, those with a proven track record. Avoid
elaborate so-called turnkey systems that claim to do everything.
Caveat emptor.
Robin Gledhill,
President
Blue-White Industries
Huntington Beach, CA, USA
www.Blue-White.com
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