EVALUATING
This section provides valuable information in evaluating your current program, your vendor and bidding water treatment programs. Finally a satirical yet accurate view of the water treatment market finishes this page.
Evaluating your vendor - Water Treatment Quiz
The general level of chemistry competence in the water treatment field is abysmal. This lack of basic knowledge is the direct cause of many problems seen in the field. Your best defense against incompetent water treatment is testing. Below is a short quiz where you can judge yourself the general competence level of your current vendor.
Questions
What does pH stand for?
What is the hydronium ion?
What are the thermodynamic implications of increasing the hydroxyl alkalinity in an aqueous solution?
How do corrosion inhibitors function?
What type of reaction describes the formation of rust.
Where does metal loss occur in the oxidation/reduction reaction of iron?
What is the Ryzner index?
How much does water expand when it freezes and at what temperature is its greatest volume.
Describe the concept of mass balance with regards to iron in boiler systems.
As pH increases what happens to sodium hypochlorite?
Answers
The lower case p is a mathematical symbol for the negative logarithm. The capital H stand for the hydronium ion. See pH
It is a hydrogen molecule with an extra proton – H3O+ - your basic acid – a proton donor. See pH
It will reduce the iron corrosion potential. The second law of thermodynamics states a reaction will proceed from a higher state of concentration to a lower one. By increasing the hydroxyl alkalinity concentration the reduction portion of the iron oxidation will not proceed, effectively stopping the reaction. See iron oxidation – Application of equations
The oxide layer formed on the metal surface acts as an electrical insulator that inhibits the flow of electrons. By stopping the flow of electrons, the corrosion process cannot progress. See iron oxidation – Application of equations
Oxidation/Reduction reaction See iron oxidation
The anodic site See iron oxidation
This equation indicates whether a specific water is either scale forming or corrosive. If the number is over 7 the water is scale forming and if the number is below 7 the water is corrosive.
It expands 9% and its largest volume is at 34F.
Mass balance is simply comparing a specific parameter as it travels thru a system.
It turns into chlorite, ClO3, an ineffective biocide over 8.3.
EVALUATING YOUR PROGRAM
There are two components in evaluating any treatment program:
Annual inspection with multiple opinions
Key questions
Annual Inspection
The annual inspection is normally the only time when the equipment is open and a thorough visual examination can be performed. It is essential that all sections of the system be checked – both the water and fire side – we have seen many examples of corrosion from atmospheric condensation on the fire side. On ferrous surfaces should be no pitting, active metal loss, or rust flakes peeling off. Copper surfaces should feel smooth (pinky insertion test) and have a patina, not a shiny surface. There should be no deposits except older scale which has been removed and falls to the bottom of the boiler/mud drum.
We strongly recommend getting two or three opinions on the system’s condition. One of the inherent problems in water treatment is the same person who sells you the program also judges it. Human nature what it is, a second opinion is a prudent move.
Key Questions
Many of these questions require an inspection so having the evaluation at this time makes sense. Questions for each specific water treatment area is listed below.
BOILER PROGRAMS
For water tube boilers we highly recommend a boroscope inspection to better determine actual conditions. Further not only do the boilers require inspection but also the associated equipment – dearators, condensate receivers, turbines and economizers.
What is the condition of the tubes – both water & fireside?
Is there any pitting?
Is scale flaking off the tubes?
During wash down do any tubes exhibit blockage?
How much scale debris is in the mud drum/bottom of the boiler and what type is it?
How does the associated equipment look, particularly the turbines?
Has the water pretreatment system operated reliably?
Is the testing regimen complete and are samples pulled from all pertinent locations?
Have the control parameters been consistently met?
COOLING PROGRAMS
Both the chillers and towers need to be inspected. We strongly recommend boroscope inspection of the tubes initially.
What is the condition of the tubes?
Is the inside surfaces smooth?
Does the copper have a patina?
Are there any deposits?
Are the tubes plugged up with debris/rust chips?
Are the strainers full and with what?
Do rust chips accumulate in distribution pan or strainer?
Is the galvanized tower experiencing white rust?
Is the tower consistently green?
LOOP PROGRAMS
The advantage of loop programs is that they are relatively easy to evaluate. A simple visual check of a loop sample can clearly indicate potential problems.
Is the sample clear and free of debris?
Does the sample have a foul odor?
Are the filters replaced frequently?
Is there glycol contamination? Does the sample smell sweet?
Do you add nitrite and then levels drop to nothing – microbes feasting on the nitrite
GENERIC BID SPECIFICATIONS
Listed below is the pertinent information needed to accurately execute a bid and to fairly compare the bidders.
BOILERS
Make-up volume & source, steam production & pressure
Pretreatment systems and effluent quality
Condensate return & quality, description of steam distribution layout
Associated equipment – dearators, economizers, condensate polishers and turbines – high purity steam requirement
Pricing including service and quantities (require dosage figures) should be based on chemicals required to treat one million lbs of steam.
COOLING TOWERS
Make-up volume & source, cycles in tower
Type of tower/controller/pumps
Current concerns / Any hi-temp surfaces – over 140F
Don’t use molybdate based programs – too expensive
Use a liquid oxidizing biocide – not bleach – for accurate dosing and good control – stabilized liquid bromine or bromine/bleach combo are effective choices.
Pricing including service package and product quantities (require dosage figures) should be based on treating one million gallons of make-up.
Top Five Misconceptions in Water Treatment
As with any industry there are inherent misconceptions in the market. Below are listed (in a satirical manner) common problems/conflicts in the water treatment business. However our best advice is caveat emptor (buyer beware).
5. There are no methods to evaluate program performance during operation.
Yes, there are several methods to evaluate program performance while the system is in operation. The primary tool we use is the mass balance studies. Simply stated we track a key parameter as it travels thru the system – what goes in should come out. For example calcium in a cooling tower. We know the incoming level so we can calculate how much should be leaving the system. If there is a difference the unaccounted material most likely remains behind as scale. We have performance evaluation parameters for all water treatment applications.
4. Large water treatment companies provide better programs than small companies. In reality a small competent firm will out perform a major player in most cases. How can a small company best a larger one.
3. All treatment products are the same.
Allow me a short story to best illustrate this point. In August 2007 The “Great” City of Chicago put out a RFP for their water treatment requirements. They specified the formulations and in many of the boiler blends they called for sodium lignosulfonate as a dispersant. Lignosulfonate is basically dirt from South Dakota and was patented as a boiler dispersant in 1915. Over the past one hundred years many more effective products have been developed. Finally these bid specifications were reviewed by their consultant no less. Contrast this with our boiler programs using the latest combination of scale dispersant, phosphonate/polymaleic, developed five years ago. There is a world of difference in products.
2. The same person who sells me the program also judges the program so do I receive a fair and honest evaluation?
Human nature being what it is the correct answer is both “yes” and “no”. Here again the integrity of your vendor is paramount. If you are unsure or skeptical of your program results request a third party evaluation. A consultant, boiler repair personnel, or a water treatment professional can do this. This is a common problem in water treatment.
1. My water treatment rep knows his chemistry. Your representative is the most important individual with regards to the success or failure of your water treatment program. Unfortunately many water treatment representatives have no formal chemistry training and therefore do not understand the basic principals of water chemistry. Finding a qualified chemist is key to a successful program. To determine if your candidate is up to speed or to just grill your existing vendor use our Water Treatment Quiz. Answers are included.