Subject Operation practices that cause frequent seal and bearing maintenance problems

Wouldn't it be wonderful if the plant operation and maintenance departments could work independently The fact of the matter is that there are three types of problems we encounter with centrifugal pumps and poor operation is one of them. If you are curious, the other two are design problems and poor maintenance practices. Seals and bearings account for over eighty five percent (85 ) of premature centrifugal pump failure. In the following paragraphs we will be looking at only those operation...

Asme Certificate Holder Listing

Engineering Resources for Industry Pressure Technology Bio Pharmaceutical Energy The 2006 ASME Congress, I November 5-10 rade tips and share ideas with engineers in different ndustries and companies around the world while attending technical sessions, forums, social events and more. > > Learn More Related Reserve Your Room at the Chicago Hilton by November 1st Congress Event ASME Micro & Nano Society-Wide Forum Don't miss the chance to showcase your research and network with worldwide...

Technical Articles

What's The Difference, Why It Matters, And How To Get It By John Baechtel Photography John Baechtel Engine dyno testing is the time-honored method of determining an engine's torque and horsepower output. The dyno's numerous sensors allow engine builders and component designers to accurately measure the various temperatures, pressures, vacuum and forces generated by testing different components on the engine. Engines don't make horsepower they convert fuel into torque. Torque is the twisting...

4551

The purchaser will specify on the date sheets the characteristics of the buffer barrier fluid. Section 4.6 addresses the circulation of the buffer barrier fluid. There will be some benefits to the user when the API specification is adopted in to the CPI industry The decision to standardize on balanced seals is a wise one. It will reduce the seal inventory of most consumers and prevent a lot of premature seal failures. Allowing slotted glands for horizontally split pumps is a good idea. It...

Enclosed Uneshaft Type Enclosed Impeller

Calculation software doing pump system calculations and pump selection can be a long manual process with opportunities for many errors. Help yourself produce accurate, consistent and error free total head calculation results with PIPE-FLO software. This sofware can resolve complicated systems with multiple branches, handle control valves and other equipment and help you do the final pump selection with the manufacturer's electronic pump performance curves providing you with customizable search...

Troubleshooting pump failures

A different method of troubleshooting pumps and seals 5-6 A little bit more about centrifugal pump cavitation 9-10 A.P.I, and C.P.I. specifications merger 12-5 Analizing the rub marks in a centrifugal pump failure 5-05 Centrifugal pump shaft displacement 9-2 Maintenance practices that cause seal & bearing problems 6-8 Operating practices that cause maintenance problems 6-7 Positive displacement pump troubleshooting 12-4 Pump bearings, why do they fail 4-12 Pump selection practices that...

Subject Troubleshooting rub marks in a centrifugal pump 505

When a centrifugal pump is disassembled there are a couple of things visible to the trained trouble shooter. He can see either corrosion or evidence of rubbing, damage or wear. When ever a rotating piece of hardware hits a stationary piece it leaves a mark that is clearly visible and capable of being analyzed for cause. This type of rub mark should never be confused with the dull appearance we see on a piece of metal that has been rotating in an abrasive slurry. In strong corrosive applications...

We have created a new version of this free online Glossary with greatly increased functionality Flash Mxbased

Please change your links to go to the ALL ABOUT PUMPS tutorial MX version home page, where a NEW AND IMPROVED version of this glossary is available, along with links to our URL for the new online FLASH-based elearning portal Note This version of our Internet Glossary of Pumps will be left online for those with slow Internet connections and for the search Engine Bots (which don't search FLASH files very well), but it will not be upgraded to the look and feel of the MX project, and new...

Ho

See another example of the design and calculations for a new fountain pump system Examples of common residential water systems This next figure shows a typical small residential water system.The yellow tank is an accumulator. The following figures show various common water systems and indicates what the static head, the friction head and the pump total head. This web site will tell you the flow requirement of each nozzle and the nozzle head requirement. Calculate the pump discharge pressure...

Subject Why do not good seals wear out

We know that a mechanical seal is supposed to run until the carbon wears down, but our experience shows us this never happens with the original equipment seal that came installed in the pump. We buy an expensive new mechanical seal and that one doesn't wear out either. What is wrong Was the new seal a waste of money Not really. You are doing something that appears logical, you are trying to solve the seal problem by purchasing a different seal, but that is like trying to get a good paint job on...

The Carbon Face

Indicating vibration. This can be caused by harmonic vibration, or if the rotating equipment hits a critical speed. Slipstick can occur if you are pumping a fluid with poor lubricating qualities. Mishandling is a common problem. Look for evidence of drive lug wear to eliminate this as a possibility. Vaporization of the liquid causing the faces to rapidly open and then close as the leaking fluid cools the faces. A discharge recirculation line is aimed at the...

Trouble Shooting

He following questions rnt characteristics of a pump system. v is it used in a pump system to make calculations easier. d friction head and how do they affect the flow rate in a pump system. al pump produce pressure. i flow the two most important characteristics of a centrifugal pump pump rating And what is the optimal operating point of a centrifugal pump - How to do details calculations that will allow you to size and select a centrifugal pump. - How to verify that your centrifugal pump is...

Closed Impeller Drawing

Mechanical Drawing Terms

* Multiplier to corned Priclion loss labies (in previous editions 4th Edition and earlier) cafifKit be used wiih labies m this book which are based on he Darcy-Weisbach-CoietirooK formula. ' Note the Hazon Williams Iriclion lactor C must nol be conlused with the Darcy-Weisbach-Colebrook fiiclion fador f these two friclion factors are not in any way related to each other. * Multiplier to corned Priclion loss labies (in previous editions 4th Edition and earlier) cafifKit be used wiih labies m...

List Of Known Carcinogens

Known carcinogens are defined as those substances for which the evidence from human studies indicates that there is a casual relationship between the exposure to the substance and human cancer. In the following list I have noted some commercial uses for each of the carcinogens shown. As you would expect, this is a developing subject. Be sure to use dual seals any time you have to pump these chemicals. 4-Aminobiphenyl No commercial use in the United States. Was used as a rubber antioxidant and...

21 The Emission Standard In Brief

The rule is made up of seven different subjects applicability, definitions, and general standards miscellaneous process vent provisions storage vessel provisions wastewater provisions equipment leak provisions recordkeeping and reporting provisions and emissions averaging. Each of these sections is summarized below. 2.1.1 Applicability of the Petroleum Refinery NESHAP The applicability of the rule refers to the definition of the source within the petroleum refinery source category. Petroleum...

Pipe strain

An impeller adjustment is made to compensate for normal impeller wear. Thermal growth of the shaft in both a radial and axial direction. Bad bearings or a poor bearing fit. Two direction axial thrust at start up is normal. The motor is finding its magnetic center. Cavitation - there are five separate types of damage that can be observed. The sleeve moved when the impeller was tightened. The unit is pulley driven causing excessive side thrust The impeller is positioned too far from the...

The Seal Would Leak For No Apparent Reason

The open impeller was being adjusted without resetting the seal. Many operators make their own impeller adjustments. The seal faces were opening because the equipment's sliding foot had been bolted to the floor allowing the shaft to grow through the stuffing box when the unit came up to temperature. The cartridge seal had been hydrostatically tested with water and then put into a hot oil application. It leaked almost immediately. Solution The trapped water vaporized when the unit was started....

075

See also specific speed The term Nss is also used to represent the suction specific speed. According to the Hydraulic Institute the efficiency of the pump is maximum when the suction specific speed is between 2000 and 4000. When S lies outside this range the efficiency must be derated according to the following figure. 4 e a 10 so 4c f so 100 150 4 e a 10 so 4c f so 100 150 source Pump & Systems magazine August 2005 for an article on this topic see specific-speed_primer. pel f' and here is a...

Torrington Spherical Roller Bearing Suffixes Internal Clearances Definition Radial Internal Clearances

Single Row Deep Groove Ball Bearings - Cylindrical Bore Single Row Deep Groove Ball Bearings - Tapered Bore K Self-Aligning Ball Bearings - Cylindrical Bore Self-Aligning Ball Bearings - Tapered Bore K Cylindrical Roller Bearings - Cylindrical Bore Cylindrical Roller Bearings -Tapered Bore K Spherical Roller Bearings - Cylindrical Bore Spherical Roller Bearings - Tapered Bore K Spherical Roller Bearings - Cylindrical Bore -F80 Spherical Roller Bearings - Tapered Bore K -F80 AXIAL INTERNAL...

The Hard Face

Some ceramics and silicone carbides are attacked by caustic. Check to see if your seal face contains silica. As an example both reaction bonded silicone carbide and 85 ceramic have this high silica content. The product is solidifying between the faces. Most hard faces have poor tensile or shear strength. Excessive vibration will cause cracking at the drive lug location A cryogenic fluid is freezing a lubricant that was put on the face. The elastomer is swelling up under an outside seal face....

Subject Why do pump bearings fail 412

What do we mean by good bearing life Most of us change the bearings every time we disassemble the equipment to replace the mechanical seal or the packing sleeve. Is this really a sensible thing to do If you think about it for a minute there is nothing in a bearing to wear out, there are no sacrificial parts. Bearing life is determined by the number of hours it will take for the metal to fatigue and that is a function of the load on the bearing, the number of rotations, and the amount of...

Other Considerations

Vertical pumps require venting or the seal will trap air in the stuffing box, causing high heat at the seal faces. To vent the stuffing box properly, connect a suction recirculation line between the seal flush connection and the pump suction. Vertical pump applications also present a problem for dual seal applications. You will need to provide some method of venting air trapped at the outside seal. Carbon metal composites are a good choice for heat dissipation across the carbon seal face. Try...

Controlling The Pressure In The Stuffing Box Area

Increase stuffing box pressure by installing a recirculation line from the pump discharge back to the stuffing box figure A with a close fitting bushing in the bottom of the stuffing box. Try to avoid positioning the recirculation line so that it aimed at the lapped seal faces or thin bellows seal plate materials. Eliminate the pressure drop between seal faces by using two seals with a higher pressure barrier fluid circulating between them. This is very important in the sealing of chemicals...

Subject Controlling the temperature in the stuffing box area

Many fluids are adversely affected by a change in their temperature, and when this reaction takes place seal failure is almost sure to follow. The reaction can take several forms One of the seal components can be destroyed. The elastomer, seal faces, or metal parts will almost always be altered at some degree of change in ambient temperature. Coated hard faces can heat check crack . Carbon fillers can melt and pits can form in carbon graphite faces as trapped air expands and blows out pieces of...

Barrier Or Buffer Fluid

Mechanical Seal Barrier Fluid

Any time you use two seals in an application you will need a fluid between them. If the fluid between the seals is higher than stuffing box pressure we call it barrier fluid. If it is lower than stuffing box pressure we call it buffer fluid The liquid can be circulated either by forced circulation, a pumping ring or convection. The method that you will use will be dictated by the pressure, pump speed and shaft size. All seal manufacturers have charts available to give you the correct...

Centrifugal Pump Selection How To Pick The Correct Size Pump For Your Application

We will begin by deciding what operating conditions our pump has to meet and then we will approach pump suppliers to see how closely they can satisfy these needs. Unfortunately no comprehensive theory which would permit the complete hydrodynamic design of a centrifugal pump has evolved in the many years that pumps have been around, so the pump manufacturer will be doing the best he can with the information you supply to him. To clearly define the capacity and pressure needs of our system we...