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dhourigan

Member Since 14 Jun 2012
Offline Last Active Mar 19 2017 06:37 PM
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Topics I've Started

Is Your Water Treatment Company Deceiving you?

02 June 2013 - 04:42 PM

Sometime in 2012 I was engaged in a conversation on a Professional Water Treatment Forum. The subject was about pre-passivated corrosion coupons. For those of you who are unaware, Corrosion Coupons are used by property owners and by water treaters to monitor the effectiveness of a water treatment program’s ability to prevent or control corrosion. Ideally, the coupons are matched to the metal type that the program is trying to protect. Ideally, the corrosion of the coupon should be at the same rate as the system metal to be able to monitor the actual corrosion taking place in the system. In many cases matching the corrosion rate in the system is not possible and the coupon will corrode more rapidly than the system metal. This is because the system has an established oxide coating that protects it while the coupon does not. But it is okay if the coupon corrodes faster, since the higher sensitivity to corrosion will allow you to monitor the effects of changes in the water treatment program more quickly and with greater accuracy. Minimizing the corrosion rate on the coupon will, of course, minimize the corrosion rate on the system provided that they are the same metal.

At this point someone asked where they could buy pre-passivated corrosion coupons. The alleged purpose of pre-passivating corrosion coupons is to more closely match the corrosion rate to that of the system metal. In effect this decreases the sensitivity of the corrosion coupon to actual corrosion. The problem is that there exists no standard for properly passivating a corrosion coupon to match the corrosion rate of the system metal.

Typically the pre-passivation has been done in the past to deceive the water treatment company’s customer into believing that the water treatment company is doing a better job than it is actually doing in the control of corrosion. This practice had been common place in the 1970s.

To my surprise a number of company representatives admitted to using the pre-passivated corrosion coupons, and even more expressed an interest in where they could buy them. I was shocked and disappointed that so many were cheating or wanted to cheat their customers.

I am not sure how wide spread this practice of deception is. Many simply remained silent on the subject. But this speaks volumes regarding the importance of using an independent laboratory to monitor corrosion results. It is unwise to allow your water treatment company to give themselves a grade where your equipment is concerned.

We can provide a full range of pre-weighed corrosion coupons along with an independent laboratory analysis and technical backup to monitor your program. Click here for our corrosion coupon options.

Click Here to view or download a PDF version of this post.


Here is a REALLY great sale....REALLY.

10 May 2013 - 12:29 AM

This is actually a "Dick Screwed Up" Sale.

Last year ASHRAE was moving swiftly along with their Standard 188P, Prevention of Legionellosis Associated with Building Water Systems.

This was to receive Final Approval by September of 2012. Anticipating this, I stocked up on my inventory of Legionella Test Kits.

Well, Damned if they don't all have an expiration date of 7/2013, while ASHRAE sent their Standard out for a Third Public Comment on Jan 25, 2013.

So, it will cost me a bunch to rehab all of these kits with new test strips.

Here is the deal:
Kits with 5 Test Strips are $50 off and those with 10 are $100 off. That is in the drop down menu.
Next you get a 10% discount and free shipping at check out for the lower 48 states of the USA.
Everyone gets that offer on a daily basis.

For those in this Group or anyone you know, I am offering a better deal.

You get everything listed above PLUS, an additional 30% off, if you use coupon code: linked

You will never again get a price like this on these test kits, unless I screw up again.

This offer is good until Midnight July 30, 2013 or until my supply of expiring test strips is gone.

I have provided a link to our PDF Comparison Table, which is a good place to start. Each kit name is hyperlinked to the store page where you can purchase that kit.

 

Here is the link to our PDF Comparison Table:

http://www.richardho...rison_Table.pdf


Do You sell Pre-Passivated Corrosion Coupons?

04 October 2012 - 11:32 AM

Someone actually asked me that question this week.

No we don't.

I am sorry, but that is just nuts.

Early in my career there were rumors that one of our largest competitors was soaking all of their corrosion coupons in a sodium dichromate solution so they could achieve better corrosion rates on their water treatment programs than we could. First, that is just plain cheating. But secondarily, what good does it do you to be able to point to a pristine corrosion coupon when the cooling tower has been destroyed by corrosion?

I realize that it would be nice to have a corrosion coupon of the exact same alloy, with the exact same age, the exact same stress, and the exact same passivisation layer. But that is impossible.

I would offer that the second best thing is to have a non passivated corrosion coupon of the same alloy as the metal you are trying to protect. Here is why:

When you place a corrosion coupon into a system the greatest corrosion always occurs in the first few days. With time the coupon approaches the same passivisation as the rest of the system. Corrosion rates get better the longer the coupon is in the system. Generally accepted within our industry is a 90 day test period.

If you place a passivated corrosion coupon in the cooling tower, you would expect the lowest corrosion rates initially and for corrosion to get worse the longer the coupon were left in the system. Perhaps if both coupons were left in the system together for a long enough period of time, they would both come to rest at the same corrosion rate.

But ask yourself: What am I trying to achieve? Am I trying to study corrosion coupons or am I trying to determine the best water treatment program to apply to my system which will give me the lowest possible corrosion?

If you are trying to achieve the second objective, wouldn't it be smarter to use a corrosion coupon of the same material that is even more sensitive than the system metal itself? Wouldn't this give you an early warning of trouble? It is like the canary in the coal mine that gives an early warning of methane. If you know something early, you have time to react and correct the problem.

A corrosion coupon should always be a leading indicator of corrosion not a lagging indicator.

One last note. We recommend three station racks with one coupon coming out in 30 days, one coming out in 60 days, and one coming out in 90 days. The first two are early warnings of something going badly wrong before the 90 day period is over. This allows you to make mid course corrections.

Tolyltriazole Testing

04 October 2012 - 03:12 AM

Some one asked me tonight if I can explain:

"Why the test procedures for TT states that testing should be done immediately after taking a sample?

When taking a sample and holding it for 24 hours, (a completely filled sample bottle, well-sealed) will result in a tested value reduction of anywhere from 10 to 40%.

Resampling and retesting the subject closed loop 24 hours later shows little or no result reduction.

One of AWT’s raw material suppliers prepared 10 ppm samples in distilled water, both glass and plastic containers, last year at the convention, both well sealed and not well sealed, and observed no test value reduction at 24 and 48 hours."

My thought is:

Tolyltriazole is also sold as a Ultraviolet Absorber which no doubt breaks the Nitrogen - Nitrogen bond.

Thus the test result over time would degrade, but not in the closed loop.

I am looking for solenoid valves for Cooling Tower Bleed Lines

02 October 2012 - 01:43 AM

A friend of mine asked me this question today.

I am looking for solenoid valves for Cooling Tower Bleed Lines. What kind do you recommend.

I have not used solenoids for cooling tower bleed lines in many years. They are always failing, even when you put "Y" strainers in front of the solenoids.

What I currently use are Belimo Valves. These valves are motorized open with a spring return. The results have been great. Though more expensive than solenoids, they are still a lot cheaper than motorized valve.

I know that you were not asking about steam boiler blow down solenoids, but let me point out that earlier in my career, I saw many boiler blow down valves fail. Fully motorized valves are the way to go here. That means motorized open followed by motorized close/