Pressure Vessel Testing - NDT Inspections Role Within Vessel Testing in Industry

Pressure Vessels and systems are prevalent throughout industry, from chemical, petroleum, to petrochemical, to a whole host of other industries. Pressure vessels are generally considered to be vessels which contain a maximum pressure of greater than 0.5 bar above atmospheric pressure. They come in a whole host of varieties and use is just as varied. In this article we're going to look at the safety of pressure vessels, the different types available and the role NDT (Non Destructive Testing) has to play to ensure the safety of such systems.

Regulations across the world govern the use and manufacture of such vessels and systems, this is important because the failure of such systems could have wide spread implications. Release of high energy causing injury to nearby personal, to emission of radiation, to loss of life, the effects can be severe. It's for this reason high pressure systems require careful production, and maintenance.

There are many types of pressure vessels in industry, some of the most common ones include, storage tanks, boilers, stack columns or fractional distillation towers as they're sometimes known, deaerator tanks, mixing/agitation vessels and reactors. These are the main one's to be concerned with for the purposes of looking at safety and NDT in industry. There are many more, but it we could go on forever, and this list is suitable for a general overview and day-to-day knowledge.

Ensuring the safety of these systems is obviously paramount, and to that end regulations in many countries have been put in place. Within the UK there is the PSSR (Pressure System Safety Regulations 2000) that govern the operation of equipment, and the risks associated with the release stored energy may have, with no regard for the contents released, except for steam and the scalding effect it may have. In accordance with regulations such as these, NDT can help ensure the safe operation of equipment, by inclusion within a WSE (Written Scheme of Examination). Regular testing via NDT at appropriate intervals can not only prevent injury, but also save time and money through prevention of downtime, loss of revenue/capacity, and expense in fixing major failures, so it's liberal usage is in fact positive economy.

Storage tanks can be inspected via NDT through several methods, such as LFET (Low Frequency Electromagnetic Testing, Dye Penetrant, Magnetic Particle and Ultrasonic Methods.

A complete inspection can be done via these technologies by inspecting wall plates and welds together, and inspection can be performed internally or externally depending on circumstance and the wall plates in question. The vessels can be inspected for such faults as cracks and corrosion/erosion. Typically faults occur via third party damage, or corrosion/erosion related to the natural operation of the vessels and processes involved.

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Air Cooled Heat Exchangers - What You Need to Know

Air cooled heat exchangers are 1 type of heat exchange device from a long list of heat exchangers. Generally, heat exchange equipments are devices that are particularly meant for assisting the release of heat coming from a certain volume of fluid in the direction of the other. To understand more, consider the regular home appliances at your residence, such as the refrigerators, air conditioners, along with your ordinary car radiator. They are just some simple examples of heat exchangers.

Now we will take a glance at air cooled heat exchangers. Normally, these are widely-used in industries which have a process system which produces excessive heat which must be dissipated, especially if there exists no home or local usage for it. Air coolers can perform exclusive of any cooling water from an adjacent or supporting cooling tower.

When should this equipment be used? The reply to that is once the outlet temperature is more than 20 degree Fahrenheit or -6.67 degree Celsius more than the upper limit of the expected ambient air temperature. Additionally, do not be fooled by the negative symbol of the Celsius unit. Air coolers may be utilized with nearer approach temperatures, nevertheless it has continuously come to be costly when measured up to a combination of a cooling tower and a water-cooled exchanger.

Besides the appliances as well as cars, remember that there are additional functions for air cooled heat exchanger. These uses can be seen in numerous industries, several of which include refineries, the upstream production, and petrochemical facilities. Moreover, you can also use air coolers on other conditions which have high temperatures, high pressure, acidic fluids and environments. To be more specific, air coolers are commonly utilized and set up in the everyday gas and oil refineries; gas storage facilities; compressor stations for oil pipelines; plants produces polychlorvinyl, polyethylene, glass fiber, biplastic; by-product coke plants and ammonia transportation and handling plants.

Apart from the various functions and uses of air coolers, you need to understand something about its construction. Luckily, I will give that to you. The common air cooled exchanger that is used for processing purposes are consists of a finned-tube bundle that are built inside a rectangular box headers on both ends of the tubes. The chilling air is supplied by several fans. In general, the air blows up wards via a horizontal tube bundle or sideward, for vertical tube bundles. The installed fans may be either induced or forced draft. And this is determined by whether the air is pushed or pulled all the way through the tube bundle. The air is directed by the plenum chamber, additionally, the chamber encloses the space between the fans as well as the tube bundle. And all of the various components pointed out are generally built up on legs or a pipe rack when assembled. And before I forget, the fan drive assemblage is sustained with a steel mechanical drive support system. The support system will generally be consisted of a vibration switch on every fan. The switches are specially designed to shut down a fan which has a problem, without human involvement.

To understand the inside and out of air cooled heat exchangers is literally easier said than done, and it is even tougher when you have absolutely no background on machines or mechanical terms. Though the question still remains, why are these preferred than other coolers. To start with, they're more affordable to maintain when compared with some other chemical using coolers. Secondly, it can quickly be installed. Last but not least, air cooled heat exchangers are the most environmental friendly method available up to now.

Carbon Steel Considerations For Use in Industrial Pressure Vessels

Pressure Vessels are pressurised containers designed to hold liquids or gas at a different temperature to the ambient temperature. They are found commonly in the oil, petrochemical, gas processing and energy generation industries.

The steel is forged at the mill and then shipped to a fabricator who welds the plates together to form the pressure vessel. Obviously any failure of the inner wall or welds in such a highly pressurised cylinder could prove catastrophic which is why the supply of material is governed by international law. The steel which is commonly specified by the customer is forged for its particular purpose - these purposes could include resistance to heat or resistance to corrosion or both.

One of the main problems which is found commonly in the oil and petrochemical industry is 'hydrogen induced cracking' also known as HIC. In sour service environments, hydrogen sulphide is produced which, above a certain level of pressure, can potentially corrode the steel from the inside. The corrosion rate is apportioned to the quality of steel used and failure to inspect the pressure vessel over a prolonged period could cause the cylinder to explode. Stress orientated hydrogen induced cracking (SOHIC) is a similar issue where hydrogen corrosion is present around the base metal at the weld point itself.

Pressure vessel steel can be supplied which is HIC tested to demonstrate the materials resistance to hydrogen induced cracking. Low sulphur content could be one stipulation whilst a sample could be tested under h2s conditions to measure how long the steel will last before replacement is required. The higher the resistance, the longer the steel will last.

High impact steel is tested using the Charpy V Notch Test which tests a specimen over a temperature range to show the change in ductile fracture at high temperatures to brittle fractures at low temperature revealed by a drop in impact energy. This test is especially important for steel material used in working environments which operate over a significant temperature variation.

The setting of technical standards for steel used in pressure vessels can be found in a number of organisations which include;

* ASME - American Society of Mechanical Engineers

* ASTM - American Society for Testing and Materials

* NACE - National Association of Corrosion Engineers

The quality of pressure vessel steel material has improved considerably in recent years and incidents which at one time were commonplace, are now relatively rare. This information however, does magnify the importance of procuring properly tested steel plate which is ideally suited to the working application.

Chemical Cleaning of Shell Tube Heat Exchanger

HOUSTON, TX - The Ethyl Corporation, Houston facility, recently contracted with CleanCo Systems Industrial Service Company to perform Chemical Cleaning on two of the facilities fixed shell tube heat exchangers. Tim Green, General Manager of CleanCo Systems and project supervisor explains, "The fixed tube exchanger presents a challenge for cleaning the shell side of the exchanger. The tubes are permanently welded in the shell or casing and in order to clean the surfaces of contaminates, fouling and oil or grease we utilize our chemical cleaning system and specialized equipment."

The equipment used for this project is a trailer mounted, closed loop pumping system driven by a 400 HP diesel engine and a circulating pump along with two each 250 gallon stainless steel tanks. The flow rate of the system is adjustable to up to 2000 GPM. "We utilize our own chemists and digital lab devices to determine the proper chemicals to use. We determine what form -- foam, liquid, cascading, or circulation -- as well as how strong the cleaning solution must be. No guesswork. No "one chemical fits all". We'll determine what will work -- and then go to work," Green continued.

After the chemical cleaning process, the exchangers were repositioned to the tube lancing area of CleanCo's Off-Site Heat Exchanger Cleaning Facility. A multi-tube lancing system is used with five tubes simultaneously cleaned with 10,000 psi of water knocking out all fouling and contaminates on the inside of the tubes. The facility has a state of the art water recycling system that significantly reduces water usage and the waste stream generated with this type of cleaning.

Once the exchangers were completely cleaned, CleanCo performed Eddie Current Testing and Inspection of the tubes to determine metal condition and wear prior to being placed back into operations. CleanCo Systems also provides exchanger repair and tube refits but in the case of the Ethyl exchangers, the inspections indicated they had plenty of life left in them and went right back to the plant and back into operations.

For all of your Heat Exchanger, Hydroblasting, Chemical Cleaning, Vacuum Truck Services and Hydro-Excavating needs, call CleanCo Systems at 713-304-4148 or click http://www.cleancosystems.com.

Carbon Water filters are almost as Popular as Air Coolers

Carbon water filters are very effective in removing contaminants from your water supply.

A water filter will remove toxins and contaminants from the water supply, so if you are interested in clean water for drinking, cooking and washing, it is a good idea to install one. One of the most popular types of water filters is the carbon water filter. If you have decided to install such a system, you may be interested in understanding exactly how it works.

Carbon has long been used to eliminate impurities and so it is only logical that activated carbon would be used in water filtering systems. They are one of the most effective ways to filter water, so it is no surprise that carbon filter systems are the most popular among home owners. They are almost as popular as air cooler.

The carbon water filter has a contaminate removal rate that is much higher than other systems have. There are two key elements that will improve the efficacy of the carbon system: how much carbon is in the unit, and how long the contaminants in the water are in contact with the carbon.

The scientific principals by which carbon filters remove contaminants from water are called catalytic reduction and absorption. What occurs is that negatively charged ions of the contaminant are attracted to the positively charged activated carbon, and the carbon absorbs organic compounds. In addition, certain materials present in the water, such as choloramines or chlorine are removed during the catalytic reduction process.

You can be assured that you and your family will be drinking the cleanest water possible if you install a carbon water filter system. When we consider how much we rely on our water supply, it seems like a small investment to keep it as clean and pure as possible.

You may be one of the lucky ones who does not really need a water filtering system. The only way to find out whether or not you do is to have it analyzed. Just take a sample to a lab that does that kind of testing. The results are available quickly, within a day or two, and then you can make the decision as to whether you want to install a system.

Carbon filtration systems are a good choice for your home to remove certain contaminants, but you have to realize that they cannot remove every element that may be found in the water supply, such as radio nuclides, thallium, sulfate, selenium, nickel, mercury, copper, chromium, barium, asbestos, arsenic, antimony and mineral salts, most of which are found in trace amounts in some water.

An Evaporative Air Cooler Can Help You Cool Down Without Mains Power

We live in a stunning country, it has endless beautiful vistas, incredible beaches and a climate that most of the rest of the world envy. However, while it is all well and good to be enjoy a 30+ day at the beach, if you are anywhere else then you are going to want cooling. Sure it is nice to have the almost never ending sunshine that we do here but if you do not have a cool refuge you can escape to then this heat will fast become too much for you. Often though we are not near mains power and without mains power having cooling is impossible, right? Wrong, that is where the power of evaporative cooling comes into play. Get an evaporative air cooler.

An evaporative cooler (otherwise known as a swamp cooler, desert cooler, and wet air cooler) is a device that cools air through the evaporation of water. Evaporative cooling differs from typical air conditioning systems which uses vapour-compression or absorption refrigeration cycles. Evaporative cooling works by employing water's large enthalpy of vaporization.

The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapour (evaporation), which can cool air using much less energy than refrigeration. In extremely dry climates, evaporative cooling of air has the added benefit of conditioning the air with more moisture for the comfort of building occupants.

You can get some awesome 12 volt units that will help you keep cool in even the most intense heat. These small evaporative cooling unit are totally portable, they are simply able to blow a cool breeze over the user whilst in front of the unit, they will not cool down a €room' to a controlled temperature, this is where a refrigerated unit is required. In other words, they do not refrigerate but they can cool.

Look for a unit that has all the necessary features, it should be lightweight, offer a quieter, powerful moisture proof electric fans with 80,000+ hours life span, be able to deliver air up to 50% cooler (at the vent) than ambient air temperature (when using ice water), have durable evaporative filters with increased air velocity & life span (800+ hours), be able to simply plug into 12 volt cigarette lighter socket and come with an easy to fill screw cap lid- with overfill protection.

Keep yourself cool when you are out in the heat and away from mains power with an evaporative cooler, these little units can save your life.

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Critical Aspects of Procuring High Pressure Vessels

The United States Department of Labor states that a pressure vessel is a "storage tank or vessel that has been designed to operate at pressures above 15psig." High pressure vessels are ones that are designed to hold liquids or gases at even higher pressures than regular pressure vessels or autoclaves. They need to be manufactured according to the most stringent codes so as to ensure the safety of personnel and other equipment at a site or facility.

Some common examples of materials that are contained in such vessels include ammonia, oxygen, compressed air, natural gas, a variety of chemicals, and so on. These are some examples of materials that can only be safely stored when they are pressurized. There are a number of manufacturers. However, the question is not about finding a manufacturer. It is about finding the very best manufacturer so that you can be assured of the safety of your people and processes.

Any negligence while procuring high pressure vessels could mean putting your entire factory or plant in jeopardy. Industrial accidents such as explosions, leakages, and bursts are caused due to pressure undetected faults in pressure vessels.

There are three determining factors to take into consideration when procuring these high pressure units. These are:

Engineering code compliance: Codes such as ASME and ASTM need to be stringently followed. There are separate ASME codes that regulate the manufacture, testing, and repairs of vessels. These need to be completely adhered to at all stages. If you don't see the ASME stamp, you should not invest in it. Other stamps that are important on these vessels are the U, U2 and U3 codes. This is an indication that they have been manufactured to exacting specifications.

Pressure ratings: The pressure rating is the most important part of operating a pressure vessel. When you place an order for a unit, you need to specify the range that the unit is likely to be subjected to. It is important to completely customize the pressure ratings because typically, no two processes are alike. The pressure should neither be too low, nor should it be too high.

Material usage: Much of the reliability quotient of high pressure vessels stems from their material of construction. It is obvious that the usage of high quality stainless steel will reduce the chances of deterioration and corrosion. The thickness of the housing materials has to be proportionate to the pressure levels. High pressure vessels are likely going to be subjected to vibration, corrosion, high temperatures, and so on. The material of construction needs to withstand all of these factors without affecting the performance

Ultimately, it is important to purchase these units from reputable manufacturers that can offer you standard as well as customized options.