Frequently Asked Questions | Dynaproco

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frequently asked
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q: Can I request a quote where you take care of the shipment to its final destination?

Yes.

 
q: Can Dynapro provide transportation services?

Yes, Dynapro logistics team provides shipping and brokerage services for American customers. For international shipments, we could deliver to the port of the destination countries if needed. Please free to contact our account manager or logistics team for further assistance.

 
q: How long are your delivery times?

We know how damaging downtime can be in an industrial operation, which is why we have put great efforts into this matter. Our delivery times are competitive with respect to the competition, however, as an additional improvement to our service, for each pump that you purchase with us, we send one more replacement pump to our warehouse closest to your operation. With this we ensure that you have a spare kit or spare parts available for each Dynapro pump that you have in service; offering immediate delivery for any eventuality.

 
q: Who can I contact for the status of my shipment?

For the status of a shipment, you can contact our logistics department through one of the following email address': Logistica.latam@dynaproco.com in Mexico, or Logistics@dynaproco.com in Canada. For more contact information, please visit our Contact page.

 
q: Can my merchandise travel insured?

Yes. You can request an insurance, and a small fee will be added in accordance to the value of the goods that are being shipped.

 
q: Who can I contact if my merchandise arrived damaged?

You can contact the sales representative assigned through whom the OC was requested. If you don't have a specific representative, please reach out to your nearest Dynapro contact point in our Contact page.

 
q: Dynapro Terms & Conditions

To view our General Terms & Conditions, please visit the following link.

 
 
q: What kind of payment methods do we accept?

Wire transfers, ACH transfers, E-transfers, PayPal transfers and -for existing clients- cheques.

 
q: Request from US customers for the W-9 form.

The W-9 form is only used for the US suppliers, and the Canadian equivalent would be W-8BEN-E.

 
q: What are our usual payment terms?

After we check our customer's credit history with the bank and trade references, we usually approve our customers for N-30.

 
 
q: How can I know if you have a specific part in stock?

We have an extensive list of parts ready to be shipped. To ask for a specific part's availability, please contact your nearest Dynapro warehouse. If you are looking for maintenance or replacement parts for a pump you bought from us, we have good news for you! We maintain dedicated stock for the pumps we sell. You can directly contact your sales representative or make a call to your nearest Dynapro warehouse.

 
q: Why should we change our current pumps and parts brand to Dynapro?

If your focus is on reducing consumption; both energy and wear parts, we are a good fit for you. We also have very competitive pricing if you're wanting to reduce your total cost of ownership. If you have critical applications where you require us to maintain stock, we have this option for you. To accomplish these goals, it requires a partnership and commitment from a supplier and a client. If this aligns with your goals, we are a good option for you to evaluate.

 
q: What quality are Dynapro pumps? Are they energy efficient?

Optimum Pumping Systems has always been our main focus. Our goal is to obtain the highest possible efficiency in our equipment, ensuring optimal performance and efficiency we can offer great savings in energy consumption and spare parts expense.
In order to offer a lower total cost of ownership in our equipment, and to help industries on our path towards reducing our carbon footprint, we put at your disposal a dedicated, multidisciplinary team of pump professionals; our team, focused on Ethical, Environmental Engineering can help you determine which sizes, materials and equipment is the best for your application and make sure you get the most out of your equipment.
In addition, our post-sales service is excellent at keeping track of your equipment's performanec and adjusting accordingly to give you the best efficiency during the life of your pumps.
This has helped us to provide lower cost of ownership while lowering the industries' pumping systems environmental impact.

 
q: Are Dynapro pumps efficient? What about the quality?

Optimum Pumping Systems has always been our main focus. Our goal is to obtain the highest possible efficiency in our equipment, ensuring optimal performance and efficiency we can offer great savings in energy consumption and spare parts expense.

In order to offer a lower total cost of ownership in our equipment, and to help industries on our path towards reducing our carbon footprint, we put at your disposal a dedicated, multidisciplinary team of pump professionals; our team, focused on Ethical, Environmental Engineering can help you determine which sizes, materials and equipment is the best for your application and make sure you get the most out of your equipment.

In addition, our post-sales service is excellent at keeping track of your equipment's performanec and adjusting accordingly to give you the best efficiency during the life of your pumps.

This has helped us to provide lower cost of ownership while lowering the industries' pumping systems environmental impact.

 
q: What data do I have to provide in order to get a quote for a pump?

- Fluid and its characteristics: pH, percentage of solids, temperature, specific gravity, viscosity and density.
- Flow
- TDH
- Calculation elements for NPSH available.

 
q: Why is technical data necessary for a pump to be offered for a process?

It is very important to have the complete data necessary for an application, since in the design of the selection of a pump it is handled as an exact science and not having or assuming a data can cause problems for the client during the process, such as high consumption of spare parts and maintenance, high energy consumption, lack of flow or low dynamic load. Dynapro does not work on direct replacement of pumps, since we could drag previous selection problems and only with complete and correct data can we reach the solution of root problems.

 
q: Is it important to know the process fluid?

Yes, with the fluid data we can propose the best material that suits the process and thus prolong the life of your pump.

 
 
q: Can you propose a direct replacement for pumps of another brand?

Yes, in addition to our own pump lines, we can offer 100% interchangeable parts with other OEM brands. For more information, contact one of our service engineers, we are sure we can give you the help you need.

 
q: Do you sell pumps from a brand other than Dynapro?

We manufacture our own pumps so we only sell Dynapro pumps.

 
q: Why should I switch my parts to Dynapro? I already have the best brands working with me?

We handle spare parts, 100% interchangeable with OEMs because the same plants that supply our parts are the same as those that have produced for other OEMs. Our advantage is in the direct sale of these high-quality spare parts. In addition to having a warehouse for spare parts in both Mexico and Canada, we also have distributors throughout North America. Our stock is readily available for our clients. On request, we dedicate stock to your critical applications.

 
q: I prefer to keep the gasket sealed. The mechanical seal will break easily.

The mechanical seals that Dynapro handles are of high quality and robust, actually 90% of the failures in mechanical seals are due to operation and maintenance problems, with our advice we are sure your seals can achieve a long useful life and that they are a solution efficient and not a problem.

 
q: Does Dynapro sell motors without a pump?

No. We manufacture pumps so motors are only priced with one pump.

 
q: Do all pumps come with a motor?

Our pumps can be quoted with or without motor, it depends on the client's request.

 
q: Do you sell non-Dynapro pump parts?

Some of our pumps are 100% interchangeable with other brands, so depending on the pump model, we can quote the replacement parts.

 
q: Is the Dynapro SRL Pump dimensionally the same as our Interchangeable Denver SRL Pump?

No. They’re not dimensionally the same. Although, the hydraulic of the pumps are identical, which means their performance is exactly the same.

 
q: What is the difference in your standard materials for the Dynapro SRL Pump and our Interchangeable Denver SRL Pump?

The standard material for the Interchangeable Denver SRL is carbon steel for the shaft sleeve, lantern ring, and packing gland, whereas the standard material for the Dynapro SRL is 420SS for the shaft sleeve, and 316SS for the lantern ring & packing gland. This helps us start with a higher quality construction standard material, increasing the wear-life of your pumps.

 
q: Can we change our sealing to a mechanical seal while having a high percentage of solids in the slurry?

Yes, we can analyze your process and fluid to offer the appropriate solution with the mechanical seal , which can be dry, semi dry or handle an API plan depending on the case that applies.

 
q: Do Dynapro mechanical seals have the same durability?

Yes, our mechanical seals are of high quality and can give a high durability equal to or greater than the seals you know.

 
q: I need to add mobility to a pump for a new process.

It is extremely important to know the points where the pump is to be operated in order to make the proper selection between these different points. It is not advisable to operate a pump at different points without making sure you are using it with the correct parameters. Dynapro has self-priming and internal combustion engine pump options as well as the appropriate engineering equipment to determine if your application is suitable for these pumps.

 
q: Do your Liners fit? Could we have a fitting problem? It happens often with other providers.

Our liners are 100% compatible and hunt correctly with OEM (Original Equipment Manufacturer) brands, however, it is necessary to determine if the bombs are correctly assembled. It is common to see in the field that casings or covers that fit the screws are changed. With this, the liners would no longer be correct for those new pieces. In the case of marketers, normally their liners do not come from the OEM factory like ours, so it is common to see fit problems.

 
 
q: The pump is not giving the required flow.

The most important factor is determining whether the pump has been correctly selected for your application. If the selection is adequate, we must analyze the operating and maintenance conditions that usually contribute to the detriment of the flow required in a system. If you have flow problems with our - or any - pumping equipment, contact our engineers and we will help you determine where the problem is.

 
q: My pump is cavitating. What could be happening?

There are many reasons why a pump may be cavitating, from poor purge or prime to poor NPSH. In order to solve this problem, it is important to know the conditions under which the equipment is working. The problem of cavitation in a pump is a very extensive and recurring topic. If you need to solve a cavitation problem, you can contact our service engineers to study your case.

 
q: How can I increase the flow of my pump without changing the equipment?

Depending on the desired increase or decrease, you can choose from a change in speed, a larger or smaller impeller diameter, to a motor change. With an adequate engineering analysis, we can determine which is the most optimal and profitable way to make these modifications.

 
q: What can we do to make a pump equipment last longer?

There are many factors that influence the lifespan of pumping equipment. A correct selection, a correct operation and a correct maintenance. Depending on the application, some factors that tend to have an important influence on the duration of the equipment are the factors of speed, materials, and design. Our engineers previously study the application, looking for the best operating point to be able to provide the equipment with a long-lasting option. A simple speed factor can give us the opportunity to provide a choice of equipment that will make its parts last 3 times longer.

 
q: Seal water is diluting my process. How can I solve that?

We can considerably reduce the dilution by seal water, using mechanical seals, at Dynapro we handle dry and semi-dry seals, which can be the option to reduce the dilution of the process from 99 to 100%

 
q: Engine bearings have to be replaced very often. For what is this?

Generally, bearing failures are related to installation, inadequate lubrication or excessive vibrations in the equipment.

 
q: The motor is always working in over-amperage. For what is this?

If this occurs at the beginning of the equipment use, it is probably due to an incorrect selection regarding the dynamic load. If the over-amperage occurs after it has been operating correctly, it is possible that some change in dynamic load has arisen. If not, it may be due to fouling in the discharge pipes or physical and chemical changes in the fluid.

 
q: We are replacing bushings too often. How can it be solved?

Bushing problems are often related to equipment lubrication. To solve this, it is necessary to check that a correct lubrication is being applied. Also, it is important to determine if the correct bushing is being used for the equipment.

 
q: WHY ISN'T MY PUMP DELIVERING FLUID?
Suction and/or discharge valve(s) closed or partially closed.

Open valves.

Supply tank empty

- Refill supply tank.
- Install double mechanical seal and barrier system.
- Install shutdown instrumentation.

Insufficient immersion of suction pipe or bell, vortexing.

- Lower suction or rise sump level.
- Reduce flow rate.

Wrong direction of rotation.

- Check rotation with arrow on casing - reverese polarity motor.
- Note: If impeller unscrews, check for damage.

Speed too low.

- Correct speed.
- Check records for proper speed.

Strainer or flame arrestor partially clogged.

- Inspect and clean.
- Check orientation.
- Properly sized?
- Remove if start up strainer no longer needed.

Check valve plugged or installed backwards - Unplug or repair check valve.
- Reinstall in proper orientation.

Obstructions in lines or pump housing - Inspect and clear.
- Improper piping.
- Check for loose valve seat.

Pump impeller clogged
- Check for damage and clean.

Pump not primed - Fill pump & suction piping completely with liquid.
- Remove all (air/ gas) from pump, piping and valves.
- Eliminate high points in suction piping.
- Check for faulty foot valve or check valve, air vent.

Pump is cavitating (symptom for liquid vaporizing in suction system), suction recirculation, discharge recirculation - If pump is above liquid level, raise liquid level closer to pump, or lower the pump.
- If liquid is above pump, increase liquid level elevation or increase suction pipe size.
- Change pump size or speed.
- Check for pipe restrictions.
- Check air leakage through packing.
- Install full port valve.
- Check boiling point margin (flash point).
- Reduce piping losses by modifying improper piping.
- Compare flow to BEP.
- Check NPSHa/NPSHr margin.

Air/ gas entrainment in liquid - Check for gas/ air in suction system/ piping.
- Install gas separation chamber in suction tank/line.
- Check well pipe: too short, or missing.
- Check for air leaks through gaskets, packing or seals.
- Check for air leaks in suction pipe.
- Open air vent valve.

Mismatched pumps in parallel operation - Check design parameters.
- If pumps are properly matched, check for matching piping.

Pump too small (total system head higher than design head of pump)
- Decrease system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Increase pump speed.
- Install proper size pump.

 
q: WHY IS MY PUMP'S FLOW LOW?

Suction &/ or discharge valve(s) closed or partially closed
- Open Valves

Wrong direction of rotation
- Check rotation with arrow on casing-reverse polarity on motor
- Note: If impeller unscrews, check for damage.

Speed too low
- Correct speed.
- Check records for proper speed.

Obstructions in lines or pump housing
- Inspect and clear.
- Improper piping.
- Check for loose valve seat.

Strainer or flame arrestor partially clogged
- Inspect and clean.
- Check orientation.
- Properly sized?
- Remove if start up strainer is no longer needed.

Pump impeller clogged
- Check for damage and clean.

Impeller installed backwards (double suction pumps only)
Inspect

Wrong impeller size
- Verify proper impeller size.

Check valve plugged or installed backwards
- Unplug or repair check valve.
- Reinstall in proper orientation.

Internal wear (reduces throughout capability)
- Check impeller clearance.
- Check for pipe strain.
- Check for cavitation.
- Check for corrosion wear, casing wear.
- Pump metallurgy too soft for abrasives.

Air/ gas entrainment in liquid
- Check for gas/ air in suction system/ piping.
- Install gas separation chamber in suction tank/line.
- Checking for well pipe, too short, or missing.
- Check for air leaks through gaskets, packing, or seals.
- Check for air leaks in suction pipe.
- Open air vent valve.

Pump is cavitating (symptom for liquid vaporizing in suction discharge recirculation)
- If pump is above liquid level, raise liquid level closer to pump or lower the pump.
- If liquid is above pump, increase liquid level elevation or increase suction pipe size.
- Change pump size or speed.
- Check for pipe restrictions.
- Check air leakage through packing.
- Install full port valve.
- Check boiling point margin (flash point).
- Reduce piping losses by modifying improper piping.
- Compare flow to BEP.
- Check NPSHa/NPSHr margin.

Insufficient immersion of suction pipe or bell, vortexing
- Lower suction pipe or raise sump level.
- Reduce flow rate.

Viscosity too high, 500 cps most pumps, 1000 cps maximum under special designs
- Heat up liquid to reduce viscosity.
- Increase size of discharge piping to reduce pressure loss.
- Use larger driver or change type of pump.
- Slow pump down.

Mismatched pumps in parallel operation
- Check design parameters.
- If pumps are properly matched, check for matching piping.

Pump too small (total system head higher than design head of pump)
- Decrease system resistance to obtain design flow.
- Check design parameters such impeller size, etc.
- Increase pump speed.
- Install proper size pump.

 
q: WHY IS THE FLOW OF MY PUMP INTERMITTENT?

Supply tank empty
- Refill supply tank.
- Install automatic refill system.

Obstructions in lines or pump housing
- Inspect and clear.
- Improper piping.
- Check for loose valve seat.

Mismatched pumps in parallel operation
- Check design parameters.
- If pumps are properly matched, check for matching piping.

Air/ gas entrainment in liquid
- Check for gas/ air in suction system/ piping.
- Install gas separation chamber in suction tank/line.
- Checking for well pipe, too short, or missing.
- Check for air leaks through gaskets, packing, or seals.
- Check for air leaks in suction pipe.
- Open air vent valve.

Insufficient immersion of suction pipe or bell, vortexing
- Lower suction pipe or raise sump level.
- Reduce flow rate.

Pump is cavitating (symptom for liquid vaporizing in suction discharge re-circulation)
- If pump is above liquid level, raise liquid level closer to pump or lower the pump.
- If liquid is above pump, increase liquid level, elevation or increase suction pipe size.
- Change pump size or speed.
- Check for pipe restrictions.
- Check air leakage through packing.
- Install full port valve.
- Check boiling point margin (flash point).
- Reduce piping losses by modifying improper piping.
- Compare flow to BEP.
- Check NPSHa/NPSHr margin.

Process changes
- Verify if system changes exceed pump and piping design-resize pump and piping.

 
q: WHY IS THE PUMP'S DISCHARGE PRESSURE INSUFFICIENT?

Speed too low
- Correct speed.
- Check records for proper speed.

Wrong direction of rotation
- Check rotation with arrow on casing-reverse polarity on motor
- Note: If impeller unscrews, check for damage.

Air/ gas entrainment in liquid
- Check for gas/ air in suction system/ piping.
- Install gas separation chamber in suction tank/line.
- Checking for well pipe, too short, or missing.
- Check for air leaks through gaskets, packing, or seals.
- Check for air leaks in suction pipe.
- Open air vent valve.

Wrong impeller size
- Verify proper impeller size.
Internal wear (reduces pump performance capability)
- Check impeller clearance.
- Check for pipe strain.
- Check for cavitation.
- Check for corrosion wear and casing wear.
- Pump metallurgy too soft for abrasives.

Impeller installed backward (double suction pumps only)
- Inspect.

Obstructions in lines or pump housing
- Inspect and clear.
- Improper piping.
- Check for loose valve seat.

Pump impeller clogged
- Check for damage and clean.

Pump too small (total system head higher than design head of pump)
- Decrease system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Increase pump speed.
- Install proper size pump.

 
q: WHY DO MY MECHANICAL SEALS NOT LAST?

Evaporation or solidification in stuffing box and on seal faces
- Install double seal & barrier system.
- Keep stuffing box at proper temperature.

Improper operation procedures
- Verify that Operations does not start up & shut down pump improperly.
- Discontinue dead-heading pump.
- Avoid running pump dry.
- Gravity drain through pump.
- Have purge system valved out.
- Work with Operations to change bad habits or work with engineering to design around.

Misalignment
"- Check angular and parallel alignment between pump & driver.
- Eliminate stilt-mounted baseplate.
- Check for loose mounting.
- Eliminate conduit and piping strain.
- Check for thermal growth.

Inadequate grouting of base or stilt-mounted
- Check grouting. Is it cracked, crumbling, air voids, etc. Was it grouted to current industry practices? Consult Process Industry-Practice RF-IE686.
- If stilt-mounted, grout baseplate.
Casing distorted from pipe strain
- Check orientation of bearing adaptor.
- Check for misalignment of pipe.
- Check pump for wear between casing and rotating elements.
- Analyze piping loads.
- Check for pipe supports.
- Check for proper spring hanger setting.
- Is suction piping supported within 1 to 3 feet of the pump? Is vertical piping supported from above using pipe hangers or spring hangers? Verify proper support with engineering.

Bent shaft
- Check TIR at impeller end (should not exceed 0.002"). Replace shaft & bearings if necessary.

Unbalance Pump
- Balance impeller.

Wrong impeller size
- Verify proper impeller size.

Pump too small (total system head higher than design head of pump)
- Decrease system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Increase pump speed.
- Install proper size pump.
- If pump is above liquid level, raise liquid level closer to pump or lower the pump.

Pump is cavitating (symptom for liquid vaporizing in suction system), suction re-circulation, discharge re-circulation
- If liquid is above pump, increase liquid level elevation or increase suction pipe size.
- Change pump size or speed.
- Check for pipe restrictions.
- Check air leakage through packing.
- Install full port valve.
- Check boiling point margin (flash point).
- Reduce piping losses by modifying improper piping.
- Compare flow to BEP.
- Check NPSHa/NPSHr margin.

Viscosity too high, 500 cps most pumps, 1000 cps maximum under special designs (product not lubricating seal faces)
- Heat up liquid to reduce viscosity.
- Install seal flush.
- Install double seal & barrier system.

Supply tank empty
- Refill supply tank.
- Install double seal & barrier system.
- Install electrical shutdown.

Improper mechanical seal
- Check mechanical seal selection strategy.

Mismatched pumps in parallel operation
- Check design parameters.
- If pumps are properly matched, check for matching piping.

Pump too large (total system head lower than design head of pump; too much or too little flow causes shaft vibration and short seal life)
- Increase system resistance (add orifice or restrict discharge valve.
- Check design parameters such as impeller size, etc.
- Decrease pump speed.
- Install proper size pump.

Air/ gas entrainment in liquid
- Check for gas/ air in suction system/ piping.
- Install gas separation chamber in suction tank/line.
- Checking for well pipe, too short, or missing.
- Check for air leaks through gaskets, packing, or seals.
- Check for air leaks in suction pipe.
- Open air vent valve.

Unbalanced Driver
- Run driver disconnected from pump unit, perform vibration analysis.

 
q: VIBRATION AND NOISE PROBLEMS IN PUMPS

Pump is cavitating (symptom for liquid vaporizing in suction system), suction re-circulation, discharge re-circulation
- If pump is above liquid level, raise liquid level closer to pump or lower the pump.
- If liquid is above pump, increase liquid level elevation or increase suction pipe size.
- Change pump size or speed.
- Check for pipe restrictions.
- Check air leakage through packing.
- Install full port valve.
- Check boiling point margin (flash point). Reduce piping losses by modifying improper piping.
- Compare flow to BEP. Check NPSHa / NPSHr margin. Check pump suction energy.

Suction &/ or discharge valve(s) closed or partially closed
- Open valves.

Misalignment
- Check angular and parallel alignment between pump & driver.
- Check and eliminate any pipe strain.
- Eliminate stilt-mounted baseplate.
- Check for loose mounting.
- Eliminate rigid conduit connection.
- Check for thermal growth.

Inadequate grouting of base or stilt mounted
- Check grouting. Is it cracked, crumbling, air voids, etc. Was it grouted to current industry practices? Consult Process Industry Practice RE-IE-686.
- If stilt-mounted, grout baseplate.

Coupling problems
- Check for proper grease.
- Check for proper sizing.
- Check for contoured key.
- Use Class 1 alignment.

Bearing failures
- Inspect parts for defects-repair or replace. Have bearing mfr. analyze failed bearings and make recommendation
- Check lubrication procedures
- Check for contaminated lubricant (e.g., water)
- Check for over-lubrication. Check for under-lubrication.
- Verify (mineral) oil temperature less than 180°F (83°C).

Pump impeller clogged
- Check for damage and clean.

Bent shaft
- Check TIR at impeller end (should not exceed 0.002"). Replace shaft & bearings if necessary.

Check valve plugged or installed backwards
- Unplug or repair check valve.
- Reinstall in proper orientation.

Obstructions in lines or pump housing
- Inspect and clear.
- Improper piping.
- Check for loose valve seat.

Strainer or flame arrestor partially clogged
- Inspect and clean.
- Check orientation.
- Properly sized?
- Remove if startup strainer is no longer needed.

Insufficient immersion of suction pipe or bell, vortexing
- Lower suction pipe or raise sump level.
- Reduce flow rate.

Air/ gas entrainment in liquid
- Check for gas/ air in suction system/ piping.
- Install gas separation chamber in suction tank/line.
- Check well pipe: too short, or missing.
- Check for air leaks through gaskets, packing, or seals.
- Check for air leaks in sealing system.
- Open air vent valve.

Pump too large (total system head lower than design head of pump)
- Increase system resistance to obtain design flow. Check design parameters such as impeller size, etc.
- Decrease pump speed.
- Install proper size pump.

Pump too small (total system head higher than design head of pump)
- Decrease system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Increase pump speed.
- Install proper size pump.

Wrong impeller size
- Verify proper impeller size.

Mismatched pumps in parallel operation
- Check design parameters. If pumps are properly matched, check for matching piping.

Unbalance - Driver
- Run driver disconnected from pump -perform vibration analysis.

Unbalance - Pump
- Balance impeller.

 
q: MY PUMP IS CONSUMING TOO MUCH ENERGY

Motor tripping off
- Check starter.
- Check heater elements or relay settings.
- Decrease impeller size.
- Increase motor size if too small for impeller
- If operations has increased flow or changed the liquid being pumped, resize pump.

Speed too high
- Correct speed.
- Check records for proper speed.

Wrong impeller size
- Verify proper impeller size

Pump not designed for liquid density being pumped
- Check design specific gravity.
- Check motor size.
- Check coupling size.

Pump too large (total system head lower than design head of pump)
- Increase system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Decrease pump speed.
- Install proper size pump.

Bearing failures
- Inspect parts for defects-repair or replace. Use Bearing Failure Analysis Guide.
- Check lubrication procedures.
- Check for contaminated lubricant (e.g., water).
- Check for over-lubrication.
- Check for under-lubrication.
- Verify (mineral) oil temp. less than 180°F (83°C).

Rotor impeller rubbing on casing or seal cover
- Loose impeller fit.
- Wrong rotation with threaded impellerimpeller unscrewing.
- Bent shaft.
- High nozzle loads.
- Internal running clearances too small.
- Low flow operation below the minimum allowable operating region.

Liquid viscosity too high
- Heat up liquid to reduce viscosity.
- Use larger driver or change type of pump.
- Slow pump down.

 
q: WHY DO MY PUMP BEARINGS NOT LAST?

Bearing failures
- Inspect parts for defects-repair or replace. Have bearing manufacturer analyze failed bearings and make recommendation.
- Check lubrication procedures.
- Check for contaminated lubricant (e.g., water).
- Check for over-lubrication.
- Check for under-lubrication.
- Verify (mineral) oil temperature less than 180°F (83°C).

Unbalance-Driver
- Run driver disconnected from pump unit - perform vibration analysis.

Pump is cavitating (symptom for liquid vaporizing in suction system), suction re-circulation, discharge re-circulation
- If pump is above liquid level, raise liquid level closer to pump or lower the pump.
- If liquid is above pump, increase liquid level elevation or increase suction pipe size.
- Change pump size or speed.
- Check for pipe restrictions.
- Check air leakage through packing.
- Install full port valve.
- Check boiling point margin (flash point).
- Reduce piping losses by modifying improper piping.
- Compare flow to BEP.
- Check NPSHa/ NPSHr margin.

Unbalanced-Pump
- Balance impeller.

Misalignment
- Check angular and parallel alignment between pump & driver.
- Check and eliminate any pipe strain.
- Eliminate stilt-mounted baseplate.
- Check for loose mounting.
- Eliminate rigid conduit connection.
- Check for thermal growth.

Bent shaft
- Check TIR at impeller end (should not exceed 0.002"). Replace shaft & bearings if necessary.

Casing distorted from pipe strain
- Orientation of bearing adaptor ok?
- Check for misalignment of pipe.
- Check pump for wear between casing and rotating elements.
- Analyze piping loads.
- Check for pipe supports.
- Check for proper spring hanger setting.
- Is suction piping supported within 1 to 3 feet of the pump? Is vertical piping supported from above using pipe hangers or spring hangers?
- Verify proper support with Engineering group.

Inadequate grouting of base or stilt-mounted
- Check grouting. Is it cracked, crumbling, air voids, etc. Was it grouted to current industry practices? Consult Process Industry Practice RF-IE-686
- If stilt-mounted, grout baseplate.

Pump too large (total system head lower than design head of pump)
- Increase system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Decrease pump speed.
- Install proper size pump.

Pump too small (total system head higher than design head of pump)
- Decrease system resistance to obtain design flow.
- Check design parameters such as impeller size, etc.
- Increase pump speed.
- Install proper size pump.

 
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