Dec 02, 2015 this fall, the poor economy has pushed unethical contractors even further. Benefits of helium hydrogen leak testing accurate and repeatable measurements for reliable results of leak testing. Called dpi, liquid penetrant inspection lpi, or penetrant testing pt, this is a lowcost inspection method widely used to locate surfacebreaking defects in nonporous materials metals, plastics, ceramics. How much production downtime is needed for the test. There are many areas on a heat exchanger that you can not get to for visual inspections while the heat exchanger is in the furnace. This one is about a crack i found in a heat exchanger that caused no symptoms.
The installation of the uks most modern plate heat exchanger reconditioning and service centre located in retford, nottinghamshire means were able to offer our customers a. Ths head office is located in pickering, ontario with a 6,000 square foot service center in hamilton, ontario. Locating lowlevel leaks in heat exchangers efficient plant. Weve serviced equipment for 90 years in new zealand. By applying dye penetrant testing, our techs are certified to detect common and uncommon discontinuities exposed to the materials surface. The flame generates enough co lack of oxygen, excess fuel, high temperature. Dye penetrant testing dpt for heat exchangers mechpro. In most cases, the revealed findings are fatigue cracks, grinding cracks, quench cracks, impact fractures, overload fractures and weld discontinuities. Plates are also thoroughly inspected for fatigue, pitting and any other irregularities. The majority of detection systems on the market require plants to be out of action for as many as eight hours while heat exchangers are either stripped down and painted with dye or gas pressure tested. During the plate heat exchanger crack detection process each plate is subjected to the dye penetrant test. Chemical cleaning leak detection frame refurbishing expansion and sizing dye penetrant testing dpt process. Heat exchanger crack finder solution, heat exchanger inspection.
When spraying dyes, there is also an issue with inhalation. If you have a cracked heat exchanger, you need to replace it. Uv leak detector accessories hvac test instruments. High temperatures, conductive media and nonstop operation of the device ensure that in the course of time, every heat exchanger becomes contaminated. This product uses a nondestructive ultraviolet dye that is applied onto your heat exchanger by. Each plate is dye penetrant inspected for cracks and pinholes, which is critical to ensure the regasketed plates are reusable. The cause of cracked heat exchangers avoid this common scam.
A damaged heat exchanger in a gas furnace is potentially dangerous to a homes occupants and should not be ignored. Signs and symptoms of a cracked gas furnace heat exchanger. The method describe in the paper canbe used to detect fouling byusingthe inlet and outlet temperatures and either the hot or cold mass. It is important that the heat exchanger is taken care of as hazards can build from a faulty exchanger. Heat exchanger leak detection test dye penetration youtube.
For heat exchanger tubing inspections, a probe that combines bobbin and array capabilities can offer additional flaw detection and shorter inspection times. With proprietary red dyepenetrant saturating the plate surface, and white developer solution covering the reverse side, wcr is capable of detecting even miniscule imperfections. With proprietary red dye penetrant saturating the plate surface, and white developer solution covering the reverse side, wcr is capable of detecting even miniscule imperfections. The service technician has the time, experience, or even reason to suspect the exchanger is cracked. Dye penetrant testing services paul mueller company. A co detector cannot tell you if a heat exchanger is good. Pick up some leak detection dye capsules from grainger to help you test the halogen refrigerant in your refrigeration and air conditioning systems. The cause can be improperly adjusted burners or a cracked heat exchanger. My concern is not that you have a heat exchanger crack, and i dont mean to imply that heat exchanger cracks are ok to live with. The problem when confronted with a potentially difficult situation that involved locating lowlevel leaks in a particular shellintube heat exchanger his company was fabricating, masons dan rennert made a point to investigate ultrasound. At heat exchanger ontario, we offer a leak detecting service for hex plates.
When one of these failures causes the two fluids to mix, its called a differential leak. Lmats test procedures are based on various national and international. After the dye is applied the plates are stacked to allow the dye. Pdf repair of tubetubesheet weld cracks in a cracked. Some cracks have been known to only open when the unit is fired and the heat exchanger metal is hot. Residential gas furnace heat exchanger testing douglas dewerth, p. Lpi is used to detect casting, forging, and welding surface defects such as hairline cracks, surface porosity, leaks in new products, and fatigue cracks on in. The service centre is outfitted with the equipment and expertise to optimize the performance and life time of your plates. Plate heat exchanger is highperformance and trouble free but. Dye penetrant test for plastics is done based on approved test procedure which indicates dye penetrant test technique, method and penetrant material should be used.
Jun 01, 2009 thats why its use paid off so well for mason manufacturing, a leading manufacturer of heat exchangers. Many heat exchangers are at a negative pressure in reference to the air moving over the exchanger. After a certain time, the deposits will lead to the heat exchanger no longer operating optimally, or even becoming completely clogged up. Guide to furnace heat exchanger inspection, testing, leaks how to inspect and test. Types of plate exchanger leaks virginia heat transfer. Wcr 100% dyetesting is our standard for locating cracks, pinholes, or failures.
Advanced heat exchanger tube testing selection of the best advanced ndt test method. Searching documents and internet sources the following is what i found on heat exchanger inspection methods and sources. A pencil size hole or hairline crack in a heat exchanger does not, in my opinion, justify shutting off the heat on someone in the middle of winter. Heat exchanger cracks are worth finding but they arent the most dangerous issue for your customers in most cases. A cracked heat exchanger not only spoils the performance of your furnace, but it will also create a safety threat to you and your loved ones. Jerry kellys invention for cracked heat exchanger detection steve miles, the general manager of jerry kelly, is the inventor of a heat exchanger inspection tool called visible defects. Mar 19, 2007 the crack is open when the heat exchanger metal is at or close to room temperature. A co detector can indicate a heat exchanger is cracked only if all of the following conditions occur simultaneously. Combustion check to confirm cracked heat exchanger youtube. Heat exchanger leak detection plate dyetesting wcr.
A clogged air filter restricts airflow through the furnace, overheating the heat exchanger, and eventually resulting in stress cracks. Located in the center of the furnace, it is where fire, gas and heat connect. Intermixing of the fluids due to corrosion, crack and pin hole on. Determines the preliminary size for a shell and tube heat exchanger based on the process information provided. Now that you have fixed the heat exchanger, replace it in the furnace. The heat exchanger inspection article provides you with information about the. Testexs hawkeye 2000 balanced field electromagnetic technique bfet system, was determined to be the best option for finding the suspected cracks. The system locates the cracks using ultraviolet uv dye and a uv spotlight. Mar 11, 20 meanwhile, your heat exchanger will go through a lot of stress when it is constantly overheated and cooled back down. Eddy current for crack detection entails a variety of methods, but surface array is one of the best techniques for metal sheets or irregular shapes such as tubing. Serious cracks were found at tubetotubesheet welds during the start up operation of a cracked gassteam heat exchanger in a gas plant. The dye reaches into the tightest areas through the use of a. Sep 17, 2015 a number of things can go wrong in a furnace, but of all those things, a cracked heat exchanger is one of the most severe problems.
Dye testers may say that their method has been used for many years, so it must work, even though the procedure used is not a qualified test method normally used for dye testing in the aerospace and nuclear industries. Nearly all possible leaks will cause the flow to spill out the sides of the exchanger to the ground so the problem becomes. Lack of airflow also leads to much longer heating cycles, so not only is the heat exchanger hotter than it needs to be, it also has to endure the pain for a great time. These advanced heat exchanger tube offer traceable and archiveable records that enable the following of a. If a crack makes its way through the walls of your heat exchanger, dangerous carbon monoxide fumes can leak into your homes air.
Radiotracers allow an early detection of small leakages before these develop into major pollution incidents. The american gas association has even put this in writing they say any visible crack or hole is reason for requiring replacement of the heat exchanger or furnace. Heat exchangers plate heat exchanger crack detection test. Eddy current techniques for crack detection in metal. Heat exchanger inspection methods hvac contractor talk. If you do not locate a crack or perforation the heat exchanger seams may be leaking and the. Ultrasound leak tests on heat exchangers compressed air. Pour a little bit of the chemical on the hole, and leave it to dry until it seals around the exchanger. Lastly, if you liked this article or found it helpful. Inconsistencies in some of these methods will be described shortly. Heat exchanger cracks and carbon monoxide myths by reuben saltzman in carbon monoxide alarms, cracked heat exchanger, hvac, new on december 2, 2014 i recently had a reader email this question. This tool also calculates the utility requirements for achieving the desired heat transfer. Heat exchanger leak detection plate dyetesting wcr 100% dyetesting is our standard for locating cracks, pinholes, or failures. Plate heat exchanger models, with available plate material.
Shell and tube, floating head, plate and fin, bayonet, air coolers are just a few of the types of heat transfer equipment. So far this season, we have run at least fifteen second opinions on cracked heat exchangers and we have yet to confirm a single crack. Pdf repair of tubetubesheet weld cracks in a cracked gas. What are the causes of a cracked heat exchanger in a gas. Carbon monoxide is a byproduct of the combustion process, and it can seep through the cracks of a damaged heat exchanger. Although you should certainly not wait until your carbon monoxide detector sounds to determine if your heat exchanger is broken, if you do get an alarm, it is a strong sign that damage is present. With proprietary red dyepenetrant saturating the plate surface, and white deve. My issue is that youre being lied to, and at the same time, most mechanics walk past the things that might kill you and your family. It is extremely important that all plates are tested as 90% of plates tested have less than 10% failure rate. Magnerscan is a dry test, operating with battery power, involves no viscous liquid and eliminates the above risks. Detection of cracked heat exchangers in warm air furnaces, j. Dye penetration test on weld joints that are susceptible to cracking, austenitic. Since steam is used to produce energy, corrosion of the heat exchanger is a constant maintenance problem. If you have an iron heat exchanger, then you need to find an iron repair liquid, which uses chemical reactions to seal holes in iron.
Plate heat exchanger, failure, stainless steel 316, stress crack. Cracked heat exchanger detection the jerry kelly way. Thats why its use paid off so well for mason manufacturing, a leading manufacturer of heat exchangers. How can leakage in tubes of heat exchangers can be found. The fluorescent dye is inbuilt into the filter drier at the time of manufacturing through. After the dye is applied the plates are stacked to allow the dye to work into. There are a variety of methods of inspecting or testing heat exchangers. The bobbin coil creates eddy currents in the tube wall which flow in the circumferential direction. The required heat transfer area, the number of tubes and the shell size are calculated. Every plate that heat exchanger ontario services is leak tested in order to eliminate any damaged plates. Pdf leak detection in a highpressure heat exchanger system. Hvac and refrigerationhvac test instrumentsuv leak detector accessories. Heat exchanger service center mechpro heat exchanger. Fill one side with dyed water, and see where color m.
A method for the detection of leaks in a heat exchanger having discrete flow paths for working fluid and heat exchange fluid, respectively, the method comprising introduction of a gas comprising helium within one of the flow paths, the pressure therein being higher than in the other flow path, and allowing air to flow through the other of the flow paths, causing the helium to pass in different. How to identify a differential leak in a plate heat exchanger. Radiotracer methods used for online leak detection in heat exchangers and underground pipelines can achieve the detection limits up to 0. If a crack has developed, air from the house will be forced into the combustion chamber when the blower turns on, causing some visible disturbance of the flame, he says. Jan 03, 2015 is raleigh, durham, chapel hill, garner, apex, holly springs, and wake forest premier plumbing heating and air conditioning contractor. This video is part of the heating and cooling series of training videos made to accompany my websites. Heat exchanger crack finder solution, heat exchanger. A look at a heat exchanger crack that cant be found youtube. The plates are brought into the spray booth area where the dye gets sprayed on one side only. This nondestructive method of testing allows for hygienic and thorough detection of potential defects such as leaks, cracks, and pinholes. The cause of the failure has been analyzed, and the. Easytesters heat exchanger testing and crack testing haccp.
The crack is open when the heat exchanger metal is at or close to room temperature. An independent contractor tried using dye penetrant testing to identify cracks, but was unable to find any cracking that could be responsible for the signs of leakage. Dry all filter drier with leak detection technology. In years past, with older furnaces, a heat exchanger crack or small slit could turn into a big, gaping split once the heat exchanger warmed up. The crack can be found on the molded resins or plastic due to molding stresses, unequal cooling or assembly shock. Corrosion andor cracks on other furnace components when other external parts of your furnace start showing signs of wear and tear, its highly possible that the internal parts are also beginning to. You can trust alfa laval technicians to repair and recondition your gasketed plate heat exchangers no matter the brand. To ensure the reliability and effectiveness of our plate heat exchangers, we utilize dye penetrant testing.
A cracked heat exchanger is not a problem that should be taken lightly. Broken and leaking heat exchangers are responsible for about 1,500 deaths per year in the united states, and many more people are poisoned by exposure to toxic gasses that go unfiltered by defective heat exchangers. The heat exchanger crack detection system finds even the smallest crack in a heat exchanger, says the manufacturer. Ripley this month we are going to focus on the importance of a company having a set procedure in. Pdf serious cracks were found at tubetotubesheet welds during the start up operation of a cracked gassteam heat. Magnerscan uses a laser drilled test block with verified cracks at different depths to calibrate it crack depth detection. On occasion, a plate heat exchanger phe can fail when a plate develops a small crack or in some rare instances when a gasket is dislodged or damaged. Heat exchanger testing by accutest international ltd. Louisiana and texas heat exchanger leak detection services.
Heat exchanger crack finder solution, heat exchanger inspection system. So here are my suggestions on how to find cracked heat exchangers and other furnace safety issues. In fact he recently walked along one area in his plant near a wall and found leaks in the airline, a crack in the housing of an air dryer and another leak in an air hose. The heat exchanger is a key part of the furnace and is responsible for the actual heating of air. Bobs answer to whether or not a cracked heat exchanger can be dangerous is unambiguous. One of the best ways you can protect your home from the dangers of a cracked heat exchanger is to know how those cracks develop in the first place. Dye penetrant plate inspection under ultra violet light. Lmats offers the latest advanced heat exchanger tube testing and inspection methods to assess the integrity of your heat exchange tubes thus maximising production and the life of your heat exchanger. One word of caution, any method established for leak detection has its benefits and its limitations. Heat exchanger leak detection test dye penetration phe nordic. Heat exchanger test using a penetrating dye such as magna flux. After the plates have been properly cleaned and dried. Leak detection in heat exchangers and underground pipelines. If youre not sure about the different types of heat exchangers and which product is right for you, take a look at our overview of plate heat exchanger technology.
Sometimes the heat exchanger fails, either from cracks produced by continual expansion and contraction due to heating and cooling of the metal, or from rust. Desmet3 1 eth zurich, ramistrasse 101, 8092 zurich, switzerland. The detection of circumferentially oriented cracks in heat exchanger tubing is difficult to detect with the usual bobbin probes for two reasons. The design of plate heat exchangers is very reliable since they have several failsafe spots to visibly show any leaks. The most common cause of an overheated heat exchanger is as simple as a dirty air filter. Ripley this month we are going to focus on the importance of a company having a set procedure in place for checking a heat exchanger for cracks. Heat exchanger leak test, plate heat exchanger crack testing. Mechpro offers ndt services at their seattle based service center dye penetrant testing dpt process. The system is the most sensitive and reliable insitu testing method available in the market place today and it is capable of detecting very small holes or cracks potentially down to 5 microns. This can be particularly damaging in the food, beverage and chemical industries, and can lead to significant downtime. The reason i make this blasphemous statement is twofold. Each plate is dye penetrant inspected for cracks and pinholes, which is critical to ensure the regasketed.
However, the hexteq system can be carried out while the heat exchanger contains liquid under pressure. Leak detection in a highpressure heat exchanger system in a refinery using radiotracer technique article pdf available in journal of radioanalytical and nuclear chemistry july 2014 with 464. Enough exhaust gases are emitted from the heat exchanger crack or perforation. The whole testing process only takes a few minutes to complete on any one section of a heat exchanger. A furnaces heat exchanger is a metal component that transfers heat from the fuel being burned while blocking the air in your home from mixing with the furnace exhaust. This contamination often results in reduced heat exchange. Systematic maintenance of your plate heat exchangers has. Detecting cracks not visible with dye penetrant testex inc. An oversized furnace can also cause overheating and heat exchanger cracks. The system the system uses an established and highly effective patented nondestructive testing method. Look for contamination traces, say you fill one side with salt water, and look for tds increases from each tube. Looking for nucalgon heat exchanger crack finder solution, heat exchanger inspection system 20hy29. After the leak has been repaired, the repair can be verified with this same method.
636 183 932 375 1090 1633 1161 942 859 1331 1532 1025 1231 281 1407 1438 384 1289 310 25 1091 943 540 1129 337 879 898 243 1152 1497 1301 703 885 1172