Case Study: Custom solution for a costly diaphragm failure problem


A major chemical manufacturer in Southern Indiana was having an issue with premature diaphragm failures on a chemical transfer operation.

The diaphragms in a competitors air operated double-diaphragm (AODD) pump were failing after only a short time in operation.
In this harsh application, the pumps are required to transfer chemicals from totes to other process-es in the plant. The operators must work quickly between batches and the pumps are required to pump several different chemicals each day.

After visiting with the customer and seeing the operation, it was surmised that the reason for the premature diaphragm failures was over-pressurization on the air supply and water hammer or back pressure spikes from the rapid opening and closing of valves at the beginning and end of pumping cycles.


Our team came up with the following solution; we recommended a custom package comprised of a 1.5” ARO® AODD pump in 316SS and Teflon construction with ARO® Long Life® Teflon diaphragms, an ARO® air line kit complete with air hose, air pressure regulator/filter with gauge and a 1.5” NPT, 316SS/Teflon pulsation damp-ener manufactured by Blacoh®.

Additionally, this equipment was offered on a 60-day trail basis. The customer has experienced a significant increase in diaphragm life with this system in place.

If you have a troublesome application, let us provide a solution for you!

Custom diaphragm pump package model info:

  • 1.5” ARO®, air-operated, double diaphragm pump model PD15A-ASS-STL
  • ARO® air line connection kit w/ARO® filter-regulator and gauge for air pressure control
  • 1.5” Blacoh® pulsation dampener model AOD-15-NPT


Case Study: Another Above and Beyond

Case Study: Another Above and Beyond

The R. A. Ross team goes above and beyond to keep you up and running.

Whatever it takes.

Heat exchanger plates and gaskets needed NOW!


Our customer was in need of 14 plate and Nitrile gasket sets for its heat exchanger.

The customer, whose primary function is the application of corrosion-resistance coatings for all types of metals for the automotive industry, was unable to operate without its heat exchanger and would be down until the exchanger was brought back into service.

The customer requested that we supply these parts TODAY, and indicated they would be willing to drive to pick up the parts if we could locate the correct parts for their heat exchanger. While we don’t stock parts for heat exchangers, we made numerous phone calls until we were able to work with one of our supplier’s in Tennessee that not only had the parts in stock, but was able to have the order available for pick up within a few hours. What normally would take at least a day to get delivered with expedited delivery was available to the customer and they were able to get their operations back on track within the same day. This “Whatever it takes” attitude by our team is how we operate every day, no matter how large or how small the order.

In addition to plates and gaskets for heat exchangers, we stock or can order parts, part kits and drop in replacements for the following brands of pumps, blowers and vacuum.

American Marsh
Crane Deming
Fairbanks Morse
Finish-Thompson (FTI)
Pump (IDP)
Robbins & Meyers
Smith & Loveless


Case Study: Whatever it takes

Case Study: Whatever it takes

Custom Part Duplication

The R. A. Ross team goes above and beyond to keep you up and running

Our customer was in need of a part for an older pump and faced with long leadtimes and high costs. The part needed was a custom machined eyebolt, not an off the shelf hardware store type item, and had a 10-12 week leadtime at a cost of over $400.

With one of the customer’s parts as a template R.A. Ross was able to work with one of our vendors to have the part duplicated at less than half the cost and reduce the leadtime to approx. a third of the OEM. While this was a significant savings to the customer for one it was a tremendous savings as they purchased 5 of them. The custom duplication process also gave them the option to select whatever material they wanted; carbon steel, 316ss or 304ss.

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Original part – Top bolt     Duplicate part – Bottom bolt


Case Study: Rapid Repair

Case Study: Rapid Repair

The R. A. Ross team solves repair turnaround time by at least half or better

Problem: Long lead times on repair parts making turnaround times for repairs extremely long.

Wemco model 4×11 CES, 30 HP, 120 GPM @100’ TDH, pumping coal slurry.

Wemco immersible model
E4K Hidrostal, 30 HP, 120 GPM @100 TDH,
pumping coal slurry.

Solution: A major energy company in southwest Indiana was having issues getting their Wemco submersible pumps that they use in their coal yard serviced in a timely manner. The repair company they were using was having trouble with long lead times on repair parts making the turnaround times for the repairs extremely long. After securing an appointment with the appropriate personnel, we were able to get an opportunity to repair one of the pumps as a trial to see how we could do. We also agreed to stock the appropriate repair parts in our facility to eliminate the long lead time for factory parts. We were able to cut the pump repair turnaround times by at least half or better and have repaired several pumps to date. In addition to the repairs, our quality work and customer service have earned us new replacement pump business as well.


Customer also purchased the E4K Hidrostal with the immersible motor for the “run in air” capability on the occasion when the water level drops below the level of the motor.



The screw/centrifugal impeller with open channel design combines the clog-resistant features of a vortex pump and the high efficiency of a centrifugal pump. The screw section of the WEMCO®- Hidrostal® pump performs like an Archimedes spiral. In thick sludges, slurries, and suspended solids, it burrows like a corkscrew to start the material pumping and keep it pumping. The centrifugal section produces steep head-capacity curve for non-overlaping performance. Combined, the screw/centrifugal action provides high, hydraulic efficiences and clog-resistant pumping. The pump is able to handle large soft solids with efficiencies of more than 80 percent.

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Case Study: Cost Saving Upgrade

Case Study: Cost Saving Upgrade

Chicken processing plant upgrades and saves money through R. A. Ross & Weir

When R.A. Ross & Associates introduced a local chicken plant to the WEIR WEMCO® Self-Primer pump they were very excited by what they saw. The tool-less, shimless impeller adjustment, the Buzz Saw wear plate, and superior materials of construction were among the main features they liked… and wanted! However, with relatively new self-primer pumps from a different manufacturer in use, the chicken plant could not justify the cost of replacing each unit. With its “one step ahead” style of thinking WEIR had that problem solved. When designing the WEMCO® Self-Primer, other industry standard pumps were taken into consideration. The rotating assembly in the WEMCO® Self-Primer pump was a direct replacement for the pump casing currently in use, making it possible to upgrade each unit to have the benefits of the WEMCO® Self-Primer at a lower cost than replacing the entire pump.

The Weir Self-Primer solids handling pump with Buzzsaw technology. (See reverse side for exploded
view and features.)

The process for upgrading each pump was simple. When a rotating assembly from the existing pump would go down, rather than rebuilding the assembly, a new WEMCO® Self-Primer rotating assembly and cover were swapped into the current pumps. This change out gave them the benefit of superior materials of construction like ductile iron over cast iron for the bearing housing, cast steel over ductile iron for the impeller, stainless steel 17-4PH over regular steel for the shaft, and a one-piece stainless steel impeller bolt instead of a steel bolt and washer. They also gained the patented self-cleaning Buzz Saw wear plate designed to dislodge materials as they become trapped on the impeller and moves them into the flow stream, reducing clogging of the pump. While there are many other benefits to the WEMCO® Self-Primer, like advanced safety features and an easily removable flap valve, it’s sometimes not economical or possible to replace a working pump. With that in mind WEIR made a superior product even more beneficial with the ability to upgrade competitors’ pumps.

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Case Study: Tough Repair

Case Study: Tough Repair

The R. A. Ross team’s experience and innovative
skills discover the problem behind the problem

Problem: Rush repair on a foreign pump with no parts availability.

Situation: When faced with a rush repair on a German made pump with no stocking US distributorship, our team came up with innovative solutions to get the pump back up and running. The pump was an ITP brand rotary gear pump model V60-2. The problem with the pump was that the mechanical seal was leaking. Upon inspection of the seal it was determined that the tungsten carbide rotary and the ceramic stationary were still in usable shape, but the holder for the tungsten insert was damaged.

To save the customer time and money we repaired the rotary holder, re-lapping the seal faces and installed new o-rings. With the mechanical seal back in working condition we found the real obstacle in repairing the pump was something that was not what it seemed.

The fluid being pumped was a slurry of distilled mineral spirits with aluminum powder at 260ºF- 280ºF.

With the high temperatures, all o-rings and elastomers needed to be able to handle at least 280º. The remaining obstacle was the lip seal (Figure 1) in the back of the stuffing box (which was designed to contain clean mineral spirits inside the box). The oil bottle filled with the clean mineral spirits (see picture on front page) helped keep the main seal and lip seal (or a second seal) lubricated. The factory supplied lip seal was a custom made Teflon lip seal that had an extremely long lead time. No lip seal was available quickly that could withstand the high temperature. With this stalling the repair, R. A. Ross and Associates got innovative!

SEALING DETAILS: We measured and custom fit a second complete mechanical seal to completely replace the lip seal. Lip seals start wearing immediately and leaking is just a matter of time. Instead, we installed a short height mechanical seal (Figure 2) that would fit into the limited space. We transformed the pump into a double seal arrangement giving the customer the advantage of a secondary mechanical seal in the case of a main seal failure, a BIG SAFETY improvement.

RESULT: A much improved, more reliable, SAFER, leak free pump. The pump is working flawlessly and the customer is up and running instead of waiting on parts.

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