Introducing Viking Pump O-Pro Seals

Leakage is often treated as an unpreventable inconvenience or a necessary evil for many applications. This is particularly true of viscous liquids passing through positive displacement pumps, which have a tendency to leak out along the positive displacement gear pumps

To learn more contact your sales rep or simply fill out the form on the right and a Pye-Barker representative will contact you.

The world of positive displacement pumps is very large and steadily growing. As a positive displacement pump supplier in GA, I’m often asked about the various types of pumps that are available.

A positive displacement pump supplier in GA has to be familiar with a large variety of high-pressure pump technologies in order to design a system that will emulsify or homogenize fluids. High pressure is defined as anywhere from 300 psi to 10,000 psi. Once you get into this pressure territory, you are outside your typical material transfer pumps. A small sampling of low-pressure pumps would include:

Practical experience leads to choosing the right pump or how to design a system around such a pump.

High-Pressure Positive Displacement Pumps in GA

Once you start emerging into the world of high pressure – above say 300 psi – your options are limited and things like fluid viscosity begin to play a more significant role.

Rotary Gear Pumps:  At 300 or 500 psi you can use rotary gear and pumps by manufacturers like Viking Pump. These pumps use 2 rotating gears set inside a housing with fairly tight tolerances between the gear outer edges and the housing inner wall. The tighter the tolerance between these surfaces, the more pressure the pump can theoretically handle.

These pumps typically have a difficult time pumping water-like viscosities even though their pump curves are based on water. These pumps perform better with higher viscosity fluids because there’s less chance the fluid will slip outside that gap between the gear edge and inner housing wall.

The slip is fairly significant and something to think about because with that slip comes a lot of noise. The pumps hammer and bang when struggling against these high pressures and low viscosities.  If you are pumping water-like viscosities at these pressures, these might not be the best pumps for you.

The nice thing about these pumps, however, is that they typically come in sanitary or hygienic designs good for pharma and personal care.

Progressive Cavity Pumps:  Progressive Cavity (PC) pumps are another option at this pressure region of 300-500 psi.  These pumps use a long spiral-shaped auger that rotates inside an elastomeric stator and moves fluid progressively along the auger.  Slip can occur in a similar manner at the space between the rotating auger and the stator.

The good news with these pumps is that there is no real gap between the rotating and stationary components because the metal rotor can essentially make contact with the elastomeric stator.  Now slip occurs due to compression of the elastomeric element.  These pumps handle water-like viscosities much better than the rotary gear type, but suffer flow losses due to intake efficiency drops when the viscosity is high.

Reciprocating Triplex Plunger Pumps:  These pumps work in a completely different manner altogether by actually trapping material between a set of checking valves where it’s nearly impossible for fluid to migrate or slip back.  The problem here is that these pumps cannot handle higher viscosity fluids much above 3000-4000 cps. However, they are easily cleanable, but do not bear those certificates.  Improvements can be made to handle higher viscosity by using a feed pump to pressurize the inlet.  These pumps can accommodate really high pressures now in the 10,000-psi range.

All told, it’s not as simple as Googling positive displacement pumps to find what you want.  You’ll get 973,000 results ranging from storefronts for mini vane pumps to obscure images of homemade pumping systems.

With the Internet’s overabundance of information, it’s time to seek a connection with a trusted positive displacement pump supplier in GA.  We want to be yours – call our office today and our experts will be happy to assist you.

Recently, I took you through the workings of an internal gear pump. Today I’m going to guide you through the inner workings of an external gear pump.

How do They Work?

External gear pumps use two identical gears rotating against each other to drive fluid from the suction port to the discharge port. Each gear is supported by a shaft with bearings on both sides of the gear. Typically, all four bearings operate in the pumped liquid.

Because the gears are supported on both sides, external gear pumps are often used for high pressure applications. Usually, small external gear pumps operate at 1,750 or 3,450 rpm and larger versions operate at speeds up to 640 rpm.

The design of external gear pumps allows them to be made to closer tolerances than internal gear pumps. The pump is not very forgiving of particulate in the pumped liquid. Since there are clearances at both ends of the gears, there is no end clearance adjustment for wear. When an external gear pump wears, it must be rebuilt or replaced.

External gear pumps handle viscous and watery-type liquids. Thicker liquids require careful setting of the pump speed because gear teeth come out of mesh for a short time, and viscous liquids need more time to fill the spaces between the gear teeth than thinner liquids.

The pump does not perform well under critical suction conditions. Volatile liquids tend to vaporize locally as gear teeth spaces expand rapidly. When the viscosity of pumped liquids rises, torque requirements also rise, and pump shaft strength may not be adequate. We supply torque limit information when it is a factor and advise against external gear pumps for applications when the torque requirements to pump a given liquid are beyond the tolerances of a given pump.

What Do We Use Them For?

We see external gear pumps used to pump fuel oils and lube oils, chemical additives, on hydraulics and low volume transfer applications. It is also common to use an external gear pump for chemical mixing and blending.

Score Card

Abrasives

 

Thin

Liquids

Viscous Liquids Solids Dry Prime Diff. Pressure
How well does an External Gear Pump handle it?

P

G

G

P

A

E

E = Excellent, G = Good, A = Average, P = Poor

We are continuing on with our series of ‘Know Your Pump’ so that you better know your way around the world of Positive Displacement pumps. Today we are looking at Vane Pumps.

How Does A Vane Pump Work?

Vane pumps have a rotor with radial slots, which are positioned off-center in a housing bore. Vanes that fit closely in the rotor slots slide in and out as the rotor turns. Vane action is aided by centrifugal force, hydraulic pressure, or push-rods. Pumping action is caused by the expanding and contracting volumes contained by the rotor, vanes, and housing. Vanes are the main sealing element between the suction and discharge ports and are usually made of a non-metallic composite material. Rotor bushings run in the pumped liquid or are isolated by seals.

Vane pumps usually operate between 1,000 rpm and 1,750 rpm. The pumps work well with low-viscosity liquids that easily fill the cavities and provide good suction characteristics.

Speeds must be reduced dramatically for high-viscosity applications to load the area underneath the vanes. These applications require stronger-than-normal vane material.

Because there is no metal-to-metal contact, these pumps are frequently used with low-viscosity non-lubricating liquids such as propane or solvent. This type of pump has better dry priming capability than other PD pumps.

Abrasive applications require the proper selection of vane material and seals. Vane pumps have fixed end clearances on both sides of the rotor and vanes similar to external gear pumps. Once wear occurs, this clearance cannot be adjusted, but some manufacturers supply replaceable or reversible end plates. Casing liners are a low-cost way of restoring pump performance as wear occurs.

What do we use them for?

Vane pumps are designed to handle low viscosity liquids such as LP gas (propane), ammonia, solvents, alcohol, fuel oils, gasoline, and refrigerants. They can be used to pump liquids with viscosities up to 500 cPs / 2,300 SSU.

Vane pumps are able to handle a wide range of fluid temperatures. -25°F and 500°F making them useful in a variety of applications.

Abrasives

 

Thin

Liquids

Viscous Liquids Solids Dry Prime Diff. Pressure
How well does a Vane Pump handle it?

P

E

A

P

G

A

E = Excellent, G = Good, A = Average, P = Poor

We’re back for another edition of “Know Your Pumps.” This time we take a look at another member of the positive displacement pump family: lobe pumps.

How Do They Work?

Lobe pumps are similar to external gear pumps in operation, except the pumping elements or lobes do not make contact. Lobe contact is prevented by external timing gears producing a continuous (non-pulsating) discharge.

Pump shaft support bearings are located in the timing gear case. Since the bearings are out of the pumped liquid, pressure is limited by bearing location and shaft deflection. There is not metal-to-metal contact and wear in abrasive applications is minimal. Use of multiple mechanical seals makes seal construction important.

Lobe pumps are frequently used in food applications, because they handle solids without damaging the pump or the product. Lobe pumps can pump much larger particles than can other positive displacement pumps.

Since the lobes do not make contact, and clearances are not as close as in other PD pumps, this design handles low viscosity liquids with diminished performance. Loading characteristics are not as good as other designs, and suction ability is low. High-viscosity liquids require considerably reduced speeds to achieve satisfactory performance.

Lobe pumps are cleaned by circulating a fluid through them. Cleaning is important when the product cannot remain in the pumps for sanitary reasons or when products of different colors or properties are batched.

What Do We Use Them For?

Lobe pumps are suitable for pumping materials such as polymers, paper coatings, soaps and surfactants, paints and dyes, rubber and adhesives, pharmaceuticals and food applications.

Score Card

Abrasives

 

Thin

Liquids

Viscous Liquids Solids Dry Prime Diff. Pressure
How well does a Lobe Pump handle it?

G

A

E

E

A

G

E = Excellent, G = Good, A = Average, P = Poor

Last month I shared with you six mistakes that could be shortening the life of your pumps. In this follow up article I’ll share with you another six mistakes that could be shortening the life of your pumps.

Not Minimizing Radial Force

Industry statistics indicate that the biggest reason centrifugal pumps are pulled from service is the failure of bearings and/or mechanical seals. Bearings and seals wear and tear give you a good idea of what is happening inside the pumping system.

To minimize radial force run your pump at its Best Efficiency Point (BEP). At its BEP, by design pumps will experience the lowest amount of radial force. High radial force and shaft deflection are a killer of mechanical seals and a contributing factor to bearing life reduction.

Not Changing Your Oil On Schedule.

For ball bearings, more than 85 percent of bearing failures result from contamination, either dirt and foreign material or water. Just 250 parts per million (ppm) of water will reduce bearing life by a factor of four.

Operating a pump can be similar to operating a car continuously at 60 miles per hour… Driving 24 hours per day, seven days a week, puts plenty of ‘miles on the clock’ —1,440 miles per day, 10,080 miles per week, or if you will 524,160 miles per year. You’d be checking your car’s oil regularly if you were doing those sorts of miles wouldn’t you? Why not check your pump’s oil regularly too?

Not Reducing The Risk of Cavitation.

Cavitation will create damage to the pump impeller, and resultant vibrations will affect the seals and bearings. Cavitation is minimized by having a large margin between net positive suction head available (NPSHA) and the net positive suction head required (NPSHRR).

Running Your Pump At High Speeds

A 3600-rpm pump will wear out faster than a 1800-rpm pump by a factor of 4-to-8. So if you’ve got to run a pump at high RPMs, when it does finally wear out be sure to look for a pump that can move the same volume of material while running at a lower speed.

Unbalanced Impellers

I recommend that impellers be balanced to International Organization for Standardization (ISO) 1940 grade 6.3 standards at a minimum. If the impeller is trimmed for any reason, it must be re-balanced.

An unbalanced impeller on an overhung pump or on some vertical designs can cause a condition known as shaft whip, which deflects the shaft just as a radial force does when the pump operates away from the BEP. Radial deflection and whip can occur at the same time.

Too Many Casing Penetrations

Many end users want the casing drilled and tapped for drains, vents, gauge ports or instrumentation. The problem is pump casing penetrations shorten pump life. Every penetration is primed for corrosion and stress risers. It’s a trade-off.

If you find yourself frustrated with pumps being continuously offline for unscheduled maintenance or need to increase the life of your pumps give the team at Pye-Barker a call at 404-363-6000 or drop us a line at sales@pyebarker.com we will advise you on your best options to increase your pump life.

As the saying goes nothing lasts forever. But a good pump that is well maintained can last you a VERY long time. An ANSI pump can be expected to operate for 15-20 years although many last longer than 25 years. We have had Viking Internal Gear pumps in the field for 40 years or more.

However, time and time again we see best practice being ignored which will shorten the lives of pumps considerably. Although that might sound like it is good business for us it really isn’t. It makes our products seem like they can’t last as long as we promise our clients they can.

Here are 6 common causes of reduced pump life.

Pipe Geometry

How the suction side piping is designed will have a huge effect on the life of a pump. For example designing pipes to keep the flow below 10 feet per second on the suction side makes a big difference to pump life.

As will designing your pipes so that fluid is loaded into the pump correctly makes a huge difference to both performance and longevity.

Pipe Strain

Pipe strain is caused when your suction and discharge pipes don’t line up with your pump flanges. It can cause flow problems which leads to vibration, casing distortion and damage to bearings seals and gears.

Driver Misalignment

Not making the effort to precisely line up your pump and motor can overload the pump’s radial bearings. A small misalignment of just 0.060 inches, could see a bearing or coupling issues in as little as three to five months of operation. Compare that to a 0.001 inch of misalignment, the same pump will likely operate for more than 90 months.

Fluid Properties

The Ph, viscosity and specific gravity of the fluid being pumped are all key factors in the life of your pump. Add to this the amount and abrasive qualities of any solids present in the fluid and you have a recipe to shorten your pump life.

Service

If you want your pump to run a long time without trouble, don’t start it and stop it. I’ve heard about pumps that were started and stopped every few seconds. In cases like that you are better off redesigning your system than searching for a pump that can put up with that sort of wear and tear.

Operating Temperature

Make sure your pump is rated to operate at the ambient temperatures it will be operating in. Be sure to winterize and summarize each pump accordingly. More important, however, is the rate of temperature change. Keep the rate of change to less than 2 F per minute. Different materials expand and contract at different rates, which can affect clearances and stresses – which in turn can shorten your pump’s life.

If you are having trouble with a pump that is always breaking down or isn’t lasting as long as you’d expect give the team at Pye-Barker a call on 404-363-6000 or drop us a line sales@pyebarker.com and we’ll help you get to the bottom of your troubles.

In December, I shared with you 3 Air Operated Diaphragm Pump (AODD) installation traps. There are another 3 common installation traps that I see maintenance teams make when installing them.

I thought I’d share these with you here to save you the time and hassle of having to wait until something stops working on your AODD pumps to go and troubleshoot it and fix it.

AODD Pump Installation Trap #1: Prime the Pump According To Directions

A lot of plants choose to use AODD pumps when self-priming is required. If you just switch the air flow from off to the required flow rate, you may find that there is not enough time for the fluid to be drawn into the pump to prime it…

This can be avoided by just turning down the compressed air at the regulator for a few seconds – letting the pump work at the reduced pressure – which allows it to draw the fluid into the pump and prime it.

Then you can turn the pump back to full operating speed.

AODD Pump Installation Trap #2: Ensure Your Tubing and Piping Is The Correct Size

The inlet and outlet ports on your pump are selected based on the flow rate you specify. Make sure your inlet and outlet hoses match the pump’s ports.

The main reason is cavitation. Too little flow to the pump and you’ll end up with cavitation which can ruin a pump in no time flat – leading to costly downtime and repairs. Getting the pipes to match the flow rate is worth the fraction of extra investment upfront to avoid the future problems.

Also – I’d recommend using flexible inlet/outlet piping rather than hard plumbing the pump in. As the pump speed increases the vibration increases which elevates the risk of loosening hard plumbed inlets/outlets – creating a risk of leaks forming.

AODD Pump Installation Trap #3: Clear Fluid Line Restrictions During Maintenance.

Honestly, you’d be surprised how often this step gets missed. We get called in on pumps that have broken down and find all sorts of restrictions in the fluid line. We point this out to the client and they mumble something like - “The maintenance team is supposed to look after that.”

If you’ve got a problem with your maintenance team cutting corners, be sure to inspect them – find out who’s doing their job and who isn’t. Also, it’s not hard for a maintenance supervisor to listen for the tell-tale sound of gravel in the pump or flashing around the manifold elbows which indicate cavitation.

Make sure your maintenance team is checking for

Doing your maintenance is like going to the gym for most people… We hate doing it but we feel better afterwards. If you have any questions about your existing air-operated diaphragm pumps then get in touch with our team on 404-363-6000 or drop us a line sales@pyebarker.com and we can get your questions answered.

We have a customer who manufactures fiberglass bathtubs — tubs made from materials that are more affordable than brass, copper, or cast-iron models, easier to install, and more convenient to repair.

But making them that way requires a special pump. It drives a mixture of resin and fiberglass strands around the manufacturing plant. To form the product, they mix the liquid with a chemical, which turns it into a hardened gel that fits a certain mold — a bathtub, in their case.

The manufacturer approached me with a problem. They have a Moyno progressing cavity pump that has to be rebuilt every year. You can imagine how expensive that is. They asked me if we could come up with an alternative.

The best option is to use a Viking size KK4624B abrasive liquids pump.  This pump is perfect for this application.  The cost of the pump quoted is approx. half of the cost of the rebuild parts for the Moyno pump.

We’re still going back and forward on it, since they have to coordinate the project with a shutdown schedule. But we’re looking forward to seeing their pump problem project through!

We recently dealt with a customer who extrudes cottonseed oil. This customer was using diaphragm pumps when we encountered their setup. These pumps were taxing the entire system, causing a number of efficiency problems, as well as requiring frequent maintenance. In short, they were costing the company both manpower and operational hours, which adds up to a lot of money. Looking at the system, it was clear that the pumps were inadequate for their operation.

We recommended the customer upgrade to some top-of-the-line Viking spur gear pumps. While the initial investment might have been more than the previous pumps, the overall cost of ownership would be substantially less. Immediately, the customer noticed that the operational improvement. The capabilities of their system had never been higher, and they no longer needed to worry about constant repairs. The benefits are not just short-term though. Years down the line, they will have saved money on repairs and made money from being able to run their system more often and more efficiently.

When one part of your system is overworked, it spreads quickly to other components. In this case, the diaphragm pumps put undue tax on the air compressors. When you are in an industry where every second counts, the last thing you want is to be worried about when the next problem might spring up. The costs of substandard equipment are both direct and indirect, and business owners don’t need the added stress. Thanks to Viking, this company has a low-maintenance, high-performance pump, and the owner is much happier as a result.

AUTHORIZED DISTRIBUTORS FOR

Savannah Office Address:
1105 Louisville Rd
Savannah, GA 31415
TEL: (912) 238-0303
FAX: (912) 238-5214
Forest Park (Atlanta) Address:
121 Royal Dr.
Forest Park, GA 30297
TEL: (404) 647-0986
FAX: (404) 361-8579
Sylvania Address:
452 Industrial Park Rd.
Sylvania GA 30467
FAX: (912) 564-2636
Orlando, FL Address:
524 Mid-Florida Dr., Suite 204
Orlando, FL 32824
FAX: (321) 282-6424
Main Switchboard:

(404) 647-0986

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