Above: A 1.5-inch vacuum chamber manifold, made with grade 316L with No. 4/32 Ra finish.

A preemptive approach to avoid costly mistakes

October 2015 - To contain a chemical reaction on a massive scale requires a reliable apparatus. From hair dye and soft drinks to chocolate or toxic chemicals, stainless steel tanks are a sterile mode of storage for industries as various as the liquids themselves. 

Precise and sanitary plate with documented traceability is an absolute necessity for Feldmeier Equipment Inc. Located in Syracuse, New York, Feldmeier manufactures tanks and pressure vessels for pharmaceutical, biotech and cosmetic clients and sells storage and mixing tanks used by brewers, food, dairy and beverage processing facilities. With six facilities spanning New York, Alabama, Nevada and Iowa, the family owned company buys its raw materials from Stainless Steel Services Inc., Philadelphia.  

The relationship has stood the test of time. Gregg Sollars, Feldmeier’s senior purchasing manager, says he and Stainless Steel Services President Rick Stewart have worked together for 20 years. The kinship comes from a similar place as both businesses began as and remain family-run organizations, riding the economy’s ebbs and flows. 

Feldmeier’s 52-year-old business has finished tanks for liquids spanning “pretty much any industry from hair color to candy and anything you can think of. We produce more 50,000- to 70,000-gallon tanks than any other company in the U.S.,” claims Sollars. 

Since 1976 Stainless Steel Services has provided polished plate for the pharmaceutical, energy, vacuum, food and dairy, military, and architectural industries, among others. The company’s initial customers were in the nuclear power industry but it’s the protocols and methods used to process orders from RFQ through load-out that has been valuable to fabricators and service centers.

Beyond the batch

Instead of approaching polishing with a “batch processing mentality,” the company takes into consideration that both shape and surface vary from plate to plate as each reacts differently “even in the same heat,” explains Stewart. 

According to Susanne Donnelly, sales manager at Stainless Steel Services, many polishing processors of stainless require “dead flat” material. For competitors, “incoming material has to be dead flat” to polish the plate, she explains. But since its inception, Stainless Steel Services developed and sourced equipment that could accept material that is less than ideally flat and level, allowing for flatness variations of up to 1 inch in any 72-inch dimension. 

“Today’s equipment follows that key objective,” Donnelly says. “By accommodating the plate shape, you ensure the process removes the same amount of material uniformly across the surface of the plate. High spots are not ground to the thickness of low spots, creating under-gauge issues, and low spots are not missed or partially polished as with some other methods.” 

Feldmeier buys stainless steel plate to minute specifications. “We purchase 5 Ra to 35 Ra required for pharmaceutical, food, dairy and beverage industries that each have different standards and Stainless Steel Services is always accommodating,” Sollars says.

“We need very defined smoothness tolerances that are gauged with a profilometer,” he continues. A profilometer measures the roughness of a surface. Ra values are the computed surface roughness average, less outlier high and lows. Readings are learned by using a calibrated profilometer that drags a diamond stylus perpendicular to the polish grain/surface to determine surface roughness. Typically this is done in established multiple areas of the plate surface, side to side and end to end to ensure no spot is above the designated maximum Ra.

Feldmeier purchases from 1⁄4-inch to 5⁄8-inch-thick plates as large as 120 inches wide by 340 inches long. “By industry standards, the size of some plate needed is extremely large,” says Sollars. “Stainless Steel Services can provide larger sizes than our limit.” 

Every detail

After receipt, material is thoroughly inspected, allowing Stainless Steel Services to either suggest a “fix” to tweak the material provided, or on rare occasions, reject the material and suggest replacement, says Stewart. “Over the years, the question is most often not if we can polish the material provided, [but rather] if we should,” he continues. “We consider the end use and the customers’ expectations. Frankly we consider it a bit lazy to grind-and-pack material not offering the likelihood of a first-class result. Keep in mind, once the protective covering is applied, no one’s going to see it until it’s fabricated [and] that’s too late.” 

That traceability is one aspect of the overall inspection process conducted on any of the material Feldmeier receives. “The pedigree of the products Stainless Steel Services offers is impeccable,” Sollars adds. “These plates are traced right back to the original melt and tests conducted are documented and maintained all along the way.

“We also strip and inspect every plate received underneath special lights ... making sure they meet the requirements of each order,” Sollars continues. “We have a team of inspectors that—after stripping plate of its protective PVC coating applied for shipping—ensure the Ra and pit-free finishes are met. That’s really time consuming, especially when you’re talking about a plate the size of your office.”

The process from plate to tank includes taking the flat material and rolling it into a hollow cylinder, on which heads are fit and welded at the ends, depending on tank style. The plate used to make pressure vessels for the pharmaceutical industry are considered reactors because a chemical or physical reaction will occur, Sollars explains. These pressure vessels are rated from 20 to 125 psi and are built to meet ASME codes. “Pharmaceutical tanks, which can reach 20,000 gallons, are the most tedious to fabricate,” he says, noting the company fabricates tanks as small as 1 liter or as large as 250,000 gallons. 

“We never assume anything. Through the years we’ve figured out what questions to ask and we ask the right questions upfront,” Donnelly says. “Questions like, ‘Do you know what’s being built?’ ‘What is the end use?’ This can lead to asking [whether the plate needs a] sanitary or pit-free surface. ‘Does the gauge need to meet a specific tolerance or wall thickness?’ ‘Will the final surface be electro-polished?’ or ‘Does there need to be a specific grain direction, [such as for an] architectural or weld joint configuration?’ Because sometimes that really matters, and it’s too late after the assembly or tank is built.”

Hand conditioning material, a common process that can detract from the finish if the application has higher aesthetic requirements, is one area Stainless Steel Services has been proactive. “Depending on the use, if there’s coil set or a dip in the plate, for example, it may not be useable,” Donnelly says. “We’ve had customers ask us for a quote without specifying that it is for an architectural application, but we know to always ask and provide the appropriate polish solution,” she says.

“We’ve saved our customers a lot of heartache and we’ve had them come back thanking us,” Donnelly continues. “Asking these questions—this is just part of my day to day.” MM