Experts in Pump Repair
Often, repairing an industrial pump requires more than just putting the pump back together exactly like it came apart. Why did it fail, and why does the pump need to be repaired? Where did the failure originate from? At Power Zone, we understand that small changes in the materials and design of the pump can result in significant improvements to the pump’s performance and reliability. Pump engineering is a part of every pump rebuild.
Pump engineering can range of small adjustments in the material of an o-ring or gasket, all the way to a full re-rate of a centrifugal pump, where a different performance rating is needed. Regardless of the level of pump engineering needed during a pump overhaul, Power Zone has the knowledge and expertise to get it done.
Our pump rebuilding expertise range across all types of pumps but are mainly focused on centrifugal pumps and reciprocating pumps. Each pump type has its challenges. Centrifugal pumps require a very high level of precision and attention to every detail. Reciprocating pumps, also known as plunger pumps, are a simple design. While plunger pumps may generally require less precision, economics are often a challenge of their own when repairing these pumps. Our skilled pump technicians and engineers understand these challenges and are adept at prioritizing what’s most important to the customer.
Every pump repair project has its unique challenges. These challenges are often not known until the pump is disassembled and evaluated, and the cause of failure is fully understood. Lean on our years of experience in pump repair and design to help you through your next industrial pump repair project. You won’t be disappointed!
Why Choose Power Zone for Pump Repair
Fast Turn-Around Time
At Power Zone, quick turnaround times for pump repair projects are commonplace. When a pump rebuilding timeline looks impossible, we want to hear from you!
Top Tier Quality
Quality matters! It matters in the material selected, in the machining tolerances used, and in the reporting of the pump rebuild process. A+ quality is paramount in every pump repair.
Functionality and Performance Testing
Nothing builds confidence in the pump rebuilding process like a good, rigorous pump performance test. We offer functionality and performance testing with our in-house, pump testing facility.
When cost is key, we have options. We can work on a quoted basis, or a cost-plus basis, whatever you prefer. We can also utilize our extensive inventory of used and new surplus equipment to obtain the needed parts, if necessary, instead of being limited to the price and lead time of standard pump parts supply chains.
The pump is repaired and tested. Is the project complete? Not necessarily. Much of a pump’s reliability depends on the quality and design of the system in which it is installed. For this reason, we offer commissioning and field support to ensure the installation is done correctly. Furthermore, we can provide spare pump parts for ongoing maintenance and repairs.
Types of Pumps We Repair
Industrial pumps come in many different types and sizes. The most common types of industrial pumps that we repair are centrifugal pumps and reciprocating plunger pumps.
Centrifugal pumps use a rotating impeller to propel fluid using centrifugal force. Because these pumps rotate at high RPMs, keeping the rotating assembly balanced is a large part of the pump repair process. At Power Zone, we keep each rotating assembly well within the API balancing requirements. This ensures very smooth operation and longevity in a centrifugal pump. Power Zone repairs all type of API centrifugal pumps.
A balanced rotating assembly isn’t the only consideration in a centrifugal pump, though. The impellers of a centrifugal pump have multiple vanes, and as the impeller rotates, these vanes cause a slight pulse throughout the pump and piping system. This can create a harmonic vibration and can be catastrophic to a pump. Care must be taken to avoid these situations.
The factors to consider are pressure and flow requirements, piping design, the fluid being pumped, and the speed at which the pump will generally operate. These calculations must be done by an experienced pump engineer and should always be verified in a test facility before the pump is put into operation.
Centrifugal pumps have bearings that require special care in the pump rebuilding process. Babbit bearings are often used to support the rotating assembly. Babbit bearings should always be “scraped” into place. This is a process that utilizes bluing compound to identify the high points of the bearing, then scraping those areas until the shaft is sitting on a uniform surface.
In a centrifugal pump, mechanical seals are used to seal the fluid inside the pump. Mechanical seals in a centrifugal pump are usually the most problematic part of the entire pumping system. Utmost carefulness and attention is needed to install these mechanical seals correctly, and protect them from grit and debris during the commissioning process. A mechanical seal has a far higher chance of failing during the commissioning process than it does in normal operation. For this reason, the pump repair process often includes commission of the industrial pump. The API 682 specification has numerous different seal support system plans that can be used to drastically increase the reliability of a mechanical seal, depending on the pressure, temperature, and material being pumped.
Reciprocating pumps work on a principal completely different from centrifugal pumps. In a reciprocating pump, a plunger or piston is used to displace fluid in a sealed chamber. This displacement forces the fluid through a series of check valves to create pressure. Reciprocating pumps can achieve pressures much higher than centrifugal pumps.
Although reciprocating plunger pumps do not require the level of precision that a high speed centrifugal pump requires, there are many more moving parts than a centrifugal pump. The more moving parts that exist inside of a machine, the more failure potential there is. Care must be taken with each clearance. Material and fluid compatibility should be a paramount consideration.
Plunger pumps come in a variety of designs. Triplex plunger pumps and quintuplex plunger pumps refer to the number of plungers a pump has, which is 3 and 5 respectively. There is also the variation of single acting pumps, meaning the pressure phase of the pumping action only occurs when the piston is moving in one direction, or dual acting pumps, meaning the piston can create pressure in both directions. These types of pumps are used for high pressure applications such as oil & gas gathering pipelines, saltwater injection, desalination, well drilling and descaling. Power Zone repairs a wide range of pumps for every industry.
Power Zone’s Pump Repair Process
Step 1 - Disassembly
Always the first step in the pump repair process, and a crucial one too. A seemingly straight forward process, but this step is the best chance to determine what the root cause of the pump failure is. Additionally, when a pump comes in with heavy corrosion, the disassembly process can become very challenging.
Step 2 - Cleaning and Blasting
Each component of the pump is thoroughly cleaned, and most surfaces are sand blasted. This allows for better inspection and paint adhesion later on in the pump rebuilding process.
Step 3 - Inspection
Once the pump parts are cleaned and blasted, a thorough visual inspection occurs. This includes measuring the clearances, grading surface conditions, and sometimes, sending parts off for 3rd party NDE, such as X-Ray or Ultrasonic testing.
Step 4 - Procurement
After the inspection is completed, a full list of pump parts is made and prices are obtained from OEM and aftermarket pump parts vendors. Prices are also gathered from 3rd party services, such as spray and grind on pump shafts, rebuilding mechanical seals, etc.
Step 5 - Machining
In many cases, we prefer to machine the parts ourselves using our in-house machine shop. Many pump parts such as shafts for centrifugal pumps, stuffing boxes for reciprocating pumps, and even bearings and bearing housings can be machined in our own machine shop. This gives us ultimate control over the timeframe and quality of these pump components.
Step 6 - Painting
The standard external coating that we use on pumps is epoxy primer with a urethane topcoat. This coating is very robust and resistant to the harshest of environments. Coated on surfaces that have been blasted to near-white metal, we can achieve excellent adhesion that lasts for years.
Step 7 - Assembly
Once all of the parts have been received and verified, surfaces have been repaired, pump cases have been painted, and gaskets have been created, the pump can be assembled. Seeing all of the new and repaired parts going together is one of the most rewarding parts of any equipment rebuilding process.
Step 8 - Testing
The best way to reduce risk while commissioning an industrial pump is to test it thoroughly before it ships. We test each pump in-house in our testing facility. We can perform basic functionality tests as well as full pump performance testing, including pump NPSH testing, pump vibration analysis testing, pump hydrostatic testing, and more.
Step 9 - Documentation
A quality pump repair isn’t truly quality unless it is accompanied by adequate documentation. A full rebuild report is created for each pump repair that includes data on how the pump was received into Power Zone’s system as well as how the pump was assembled, and the clearances and tolerances of each portion of the pump.
Step 10 - Commissioning
It could be argued that commissioning is the most crucial part of the pump repair process. The difference between good pump system commissioning practices and bad commissioning practices can be the difference between a reliable pump and an immediate failure, regardless of how well the pump was repaired. Power Zone often assists with industrial pump system commissioning and start-ups to ensure the pump repair project is successful clear to the end.
Contact Us for Pump Repair Services
Regardless of what type of industrial pump is being repaired, whether it be a centrifugal pump, a reciprocating pump, or some other type of positive displacement pump, Power Zone’s experienced pump engineers and industrial pump repair technicians are ready and able to help. We have shipped our products and workmanship to over 45 countries and dozens of different industries. Contact us today for pump engineering, industrial pump repair, or pump testing.
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How important is a control system for my pump?
Every pump should have some level of pump control system. On very basic systems, all that is needed is a few basic sensors such as a vibration shutdown and a bearing temperature shutdown. The more critical the application, though, the more expensive a shutdown is. An elaborate control system might be expensive but can give early warnings to a failure and can often result in planned outages instead of emergency shutdowns. Choose a pump control system that adequately protects the pump system from unexpected and costly outages. Power Zone can help with this. While experts in pump repair and installation, we are also experts in pump system control, and make all of our control cabinets in-house. This includes the PLC (programmable logic controller) as well as the HMI (human machine interface).
What are the most important preventative maintenance practices to keep my plunger pump running smoothly?
Plunger pumps have lots of moving parts, and moving parts usually need good lubrication. In the power end of the pump, ensure that the oil is kept clean and cool. Utilize a forced lubrication system and/or an oil cooler if possible. Install a magnet at the bottom of the power end to catch any loose metal particles or dust. Ensure that no water ingress is possible into the power end, change the oil often, and ensure there is a low oil level or low oil pressure shutoff switch installed in the system.
In the fluid end, care must be taken to monitor the leakage through the package. In some cases, fluid leaking out of the packing is acceptable and even necessary to keep the packing cool. In most cases, though, leaking out of the packing should be very minimal. This requires a good surface on the plungers and the right type of packing. To keep the plunger surface smooth for longer and improve sealing capabilities, use a force feed lubricator to force thick oil (Rock Drill oil or similar) into a lantern ring in the middle of the packing stack. Make sure there is a low oil shutoff switch on the force feed lubrication system.
Something that is often overlooked is a rubber baffle in between the fluid end and the power end. Baffles are cheap (less than $5 each) but can save thousands of dollars in pump repair and extend the longevity of a pump considerably. When a pump is in operation and the packing of a pump starts to fail, a high-pressure stream of fluid can leak out of the packing, along the plunger and pony rod, and jet directly into the power end, filling the power end with the fluid being pumped. A simple baffle in between the two areas stops this jet of fluid and extends the life of the power end. This can reduce or even eliminate pump repairs in some cases.
What are the most important preventative maintenance practices to keep my centrifugal pump running smoothly?
Centrifugal pumps operate at high speed. The result of this is that most failures start to show themselves first in the form of increased vibration. At a minimum, install 2 vibration transmitters on each bearing housing to monitor overall vibration and set alarm levels to alert and shut down the pump when vibration gets too high. While the pump still may need to be repaired if vibration is increased, the damage and cost of the pump repair will be far less if the pump is shut down early.
Bearings will be more reliable if the bearing temperatures are kept low. Bearing temperatures below 140 degrees F are ideal and should not operate above 200 degrees unless special oil is used. Install a cooling loop in the bearing housing or install an external cooling and filtration system if needed. Installing RTDs in each bearing to monitor actual bearing temperatures is recommended for all applications.
Seals can be made much more reliable with the proper seal support system. Seal support systems vary greatly depending on what is being pumped. For instance, if water is being pumped, all that is needed is a simple API Plan 11 which routes pumped fluid, usually taken off stage 2 or 3 of the pump, into the seal to keep it cool. Sometimes an API Plan 31 is used, which includes the use of a cyclone separator to remove any dust or grit going into the seal. In other cases, such as pumping propane or something with a flash point of less than atmospheric pressure, an elaborate seal support system such as an API Plan 66A must be used to ensure a safe and reliable pumping system. Read more about seal support system on this page.
Why is my centrifugal pump producing less pressure than it used to?
First, check if the speed of the pump has remained the same. In some pumping systems, even tiny reductions in speed in a centrifugal pump can result in reduced pressure and flow.
If the speed is constant from previous data points, and the flow is still reduced, then there are numerous issues that might be at fault.
Has the pressure increased? Increased pressure will always result in reduced flow in a centrifugal pump. If pressure has increased, check for blockages in the discharge line.
If pressure has also remained constant, it could be that your pump needs to be repaired. Wear from corrosive or erosive fluid might have caused damage to the pump impellers or pump case. The pump should be opened and evaluated for further information.