Writing Service Reports

Transcription

1 Service Technician Training Program Writing Service Reports Mark T. Lewis, CWT Peter E. Greenlimb, Ph.D., CWT 2 Service Reporting Criteria Who What When Where Why** How** 3 1

2 Service Reporting Guidelines Not Appearance of Report Required Testing Will Reporting Techniques Suggested Testing 4 Service Reporting Guidelines, contd. Who Person discussed with Persons in charge of making decisions What Systems under treatment When Time of Day, and Day of Week Reoccurring problems 5 Service Reporting Guidelines, contd. Where List systems by their proper name Why and How List the Problems Describe the Expected Problems How to Fix Them Underline the Problems Bold The Problems 6 2

3 Service Reporting Definitions Webster s Definition Noun Something Reported Periodic Statement of Condition Verb To give Information Write an Account A Formal Statement You are the Reporter!! 7 Service Report Types Spot Checks More Visits in a Day Checks the operation of the Control Equipment Comprehensive Service Visits Takes more time Checks the condition of the System being treated 8 Boiler Spot Check Service Make-up Water ph Conductivity Softener Conductivity Hardness Feedwater/Deaerator Conductivity Hardness ph Sulfite 9 3

4 Boiler Spot Check Service Boiler Conductivity (Un-Neutralized) ph Sulfite Condensate Conductivity ph 10 Cooling Water Spot Checks Make-up Water ph Conductivity Softener Conductivity Hardness Tower Conductivity ph Inhibitor Chlorine(Free and Total) 11 Spot Check Service Visits Inventory No Closed Water Testing No Scaling Indices Short brief Comments Needed with fewer plant/facility staff Ensures that the control equipment is working properly Should not be used as your primary monthly service visit. 12 4

5 Service Reporting is Vital! States the current condition of the customer s HVAC/Steam Generation equipment. States the current condition of your customer s Cooling Water and Steam Generating systems. Points out any potential problems. Serves as a form of communication. Can be used to protect you in the event of a failure. Can be used to protect you in a Court of Law. How, How, How, How 13 Service Reporting Foundations Begin each Site visit with a System Survey Record current pressures/temperatures/approaches and operating conditions. Check the Controller/Bleed Valve installations. Check the Chemical Injection points. Check the Condition of Cooling Tower Basins. Review Operator/Plant Personnel Logs. Collect and analyze all treated system samples. Understanding current operating conditions will better enable you to successfully evaluate your water treatment programs. You cannot evaluate current water sample results without a detailed system survey. 14 Site Visit System Surveys At the beginning of your Service Visit during your System Surveys Use your senses and inspect: Blowdown/Bleed Valves Alarms Chemical Feed Pumps Water Meters and Steam Chart Recorders Funny/Odd Noises Remember you are an extension of your customer s maintenance team 15 5

6 Service Visit Preparations Tools Safety Equipment Pair of Tongs Towel Screwdrivers Small Instrument Regular Channel Lock Pliers Small Crescent Wrench Flashlight 16 System Sampling and Testing Know which tests you are going to perform. Understand Sample Size and Multiplier 17 Total Hardness Testing Total Hardness The sample is buffered to a ph of 10.1, Hardness Indicator is added and forms a red complex with the calcium and magnesium. EDTA Titrant reacts first with the free calcium and magnesium ions, then bonds to the Indicator, causing it to change to a blue color at the endpoint. Interferences - At different concentrations Cobalt, Copper, Nickel, Zinc, Iron, Aluminum and Manganese. Samples 68 F or colder should be titrated slowly near the endpoint to allow enough time for the color change. 18 6

7 Calcium Hardness Testing Calcium Hardness The sample is buffered to a ph of with potassium hydroxide to precipitate Magnesium as Mg(OH) 2. Calcium Indicator is added and combines with Calcium to form a pink color. As EDTA Titrant is added, it reacts with the free Calcium present. When no free Calcium ions remain, the EDTA then removes the Calcium complexed with the indicator, causing it to change to blue. Interferences At different level than the Hardness test, Cobalt, Copper, Nickel, Zinc, Iron, Aluminum and Manganese. Samples 68 F or colder should be titrated slowly near the endpoint to allow enough time for the color change. 19 P- and M- Alkalinity Testing Phenolphthalein and Total Alkalinity The sample is treated with Sulfuric Acid to a colorimetric end point corresponding to a specific ph. Phenolphthalein Alkalinity is determined by titration to a ph of 8.3, as evidenced by the color change of the Phenolphthalein Indicator. The total Alkalinity is determined by titration to a ph between Interferences Chlorine, highly colored or turbid samples. Samples colder than 68 F, may turn color and then turn back as the colder water slows down the reaction of the reagents in the water. Don t be so quick to throw away your sample. 20 Chloride Testing Mercuric Nitrate Method The sample is titrated under acid conditions in the presence of Diphenylcarbazone Indicator Mercuric Nitrate reacts with Chloride ions to form soluble, mostly undissociated Mercuric Chloride. Upon addition of a slight excess of mercuric ion, a pink-purple complex is formed with the indicator signaling the endpoint. Interferences Chromate, Ferric Iron, Sulfite, Iodide, and Bromide. Silver Nitrate Method The sample is titrated with a Silver Nitrate Standard Solution in the presence of Potassium Chromate. The Silver Nitrate reacts with the chloride present to produce an insoluble white Silver Chloride precipitate. After all of the chloride has been precipitated, the silver ions react with the excess chromate present to form a red-brown Silver Chromate precipitate, marking the end of the titration. Interferences - Iron, Orthophosphate, Sulfite, Cyanide, Iodide and Bromide. 21 7

8 Sulfite Testing Sulfite Begin by adding 2 drops of Phenolphthalein, this indicates the ph is alkaline. The ph of the sample is lowered to an acidic ph by adding either an Acid Starch Indicator Powder or a 10% Hydrochloric Acid and Starch Indicator Solution. Sulfite titration is based on the reaction of Sulfite with Iodine in an acidic solution. At the endpoint, excess Iodine combines with the indicator to form a blue color. The titrant used, Potassium Iodide/Iodate, generates the Iodine in an acidic solution. Must be tested on a cool (<100 F sample). Hot samples cook the starch generating high false results. Cool the sample in a capped bottle. Interferences Sulfides, Nitrites and some metals, especially Copper. 22 ph Testing Electronic Method A ph electrode is an electrode that experiences a change in voltage when it is exposed to changes in the hydrogen ion concentrations. The electrode is encased in a special glass that detects the presence of hydrogen ions, and reacts by producing a leap in voltage. This voltage is then detected by a solution of electrolytes present within the bulb of the electrode, and the signal of a change in voltage is passed from the electrolyte solution, through a silver chloride wire within the electrode, to a ph meter. The ph meter is able to convert the voltage readings sent from the ph electrode into a ph scale measurement. Comparator Method Indicators develop certain shades of colors at certain ph values. Using a comparator, we can determine the ph of the solution. 23 Conductivity Testing The Conductivity of water is the ability of the water to conduct electricity (greater solids concentrations afford higher conductivity readings). This test is performed with a meter and probe, usually containing three steps: 1. Temperature compensation usually taking a few minutes to adjust for different temperatures. Without automatic temperature compensation, allow more time to conduct this test. 2. The emission of an electrical charge. 3. The reception of the charge by a second probe and conversion to conductance. For very Hot and/or Cold samples, rinse the sample cell two to three times and wait several seconds before taking a reading. 24 8

9 Spectrophotometric and Colorimetric Measures ionic species based on their absorption and emission properties. Relatively easy techniques to determine sample concentrations. Each specific test has specified testing reagents, reaction times and interferences. Colorimeters have set wavelengths. Spectrophotometers have adjustable wavelengths. 25 Cooling Makeup Service Tests ph Hardness (Total and Calcium) Total Alkalinity Conductivity Chloride Iron Copper Phosphate Silica 26 Cooling Tower Service Tests Hardness Total Alkalinity Conductivity ph Chloride Inhibitor Chlorine (Free and Total) Bacteria / Fungi / Algae Iron** Copper** Phosphate** Silica** 27 9

10 Cooling System Service Checks Record all test results Log the Chiller or Heat Exchanger Discharge Temperature Saturation Temperature Condenser and Evaporator Pressures Chilled and Condenser Water Temperatures Amps Hours Calculate LSI/RSI Calculate Ca(PO 4 ) 3 Index Calculate Cycles of Concentration Biological Growth needs Periodic Corrosion Coupons Water Meter Readings Inventory 28 Closed Loop Service Tests Conductivity ph Inhibitor Iron Copper Bacteria Populations 29 Boiler Water Makeup Service Tests ph Hardness (Total) Total Alkalinity Chloride Phosphate Silica Conductivity Iron Copper 30 10

11 Boiler Softener Service Tests Conductivity Hardness Identify Unit in Service Record Remaining Capacity 31 Feedwater / Deaerator Tests Hardness Conductivity Chloride ph Sulfite Iron Record Pressure Record Temperature Calculate Percent Return Condensate Observe the vent plume Periodic Dissolved Oxygen Studies Periodic Feedwater Composite Sampling 32 Boiler Water Service Tests Alkalinities (P-, M- and OH-) Oxygen Scavengers Scale Control Agents Polymers ph Conductivity (Un-Neutralized and Neutralized) 33 11

12 Steam Plant Service Tips Record: Steam Pressures Stack Temperatures Steam Psig Boiler Water F Condensate Service Tests Conductivity Hardness ph above 8.3 Multiple sample locations Iron and Copper Inventory Know quantities to be used on a daily basis. Know what has been used. Insure adequate inventories before your next schedules service visit. 35 Reporting Service Results Comment with at least one sentence for each system tested. List recommended Control Ranges. Highlight, bold or underline each area of concern. Recommend corrective action. Document water losses with potential costs. Follow-up problem areas with a letter. Explain each Why

13 Summarizing Service Report Results No Problems? Scaling Problems? Corrosive Environment? Water Losses? Problems with their Equipment? 37 YOU! We i

14 Service Call Priorities 1. Sign In! 2. Document Visit and Service! 40 Service Reports Record test results during the service call. Record specific plant operating data. List product inventories and confirm feed rates. Provide a written description of plant conditions. Confirm any changes that need to be made in the treatment program. Identify operator training session needs. Document equipment inspections. 41 Service Report Content Customer name and address Service date All sample test results Control limits Comments on Existing System Conditions Actions Required Customer signature 42 14

15 Service Reporting Written Service Report. Chemical usage. Inventory quantities (compare to last service report and orders shipped / received. Identify samples collected for Laboratory analysis. Check reagent inventory. 43 Service Reporting Check feed equipment for proper functioning vs. calculated feed rates. Identify what materials need to be ordered. Note the date(s) of pending equipment inspections. Inquire as to any complaints and resolve to the best of your ability. Call purpose and observations in absence of sampling and testing. 44 Service Reporting Techniques Write your report to effectively communicate with the boiler or cooling plant operator, or a maintenance department member. Review previous service reports in the file for wording suggestions. Write out scripted examples (Spell Check)