The Chemical Pump Duty Data Sheet: What Your Supplier Needs

Every Wrong Pump Started as an Incomplete Inquiry

Ask any pump manufacturer what causes wrong selections and the answer converges on the same point: incomplete duty data. The chemistry was named but not concentrated. The head figure covered static lift but not friction. The fluid was "mostly" clean. A pump selected on partial data is a pump selected for a different duty than the one it will actually run, and the difference surfaces as corrosion, cavitation, overload, or chronic underperformance within the first months. The duty data sheet exists to close that gap: it is the structured set of fluid and operating data that lets a manufacturer select and verify a pump without assumptions. This guide defines every field that matters, explains what each one decides, and provides a complete template ready to fill in.

Fluid Identity: The Chemistry Block

Chemical Name and Concentration

The fluid's name starts the file, and its concentration makes the name usable. Corrosion behavior changes with concentration, sometimes discontinuously: concentrated and dilute sulfuric acid are effectively two different fluids from a materials standpoint. Record the concentration as a range if it varies, including the extremes reached during process upsets, cleaning cycles, and batch changeovers, because the worst case, not the average, is what the wetted material must survive.

Temperature

Temperature sets the material ceiling and shifts everything else: viscosity, vapor pressure, and corrosion rate, which roughly doubles with every 10°C rise. Record normal, maximum, and minimum operating temperatures, plus any excursions from cleaning or sterilization cycles. A pump selected at average temperature and exposed to a hot cleaning cycle it was never specified for is a classic avoidable failure.

Composition Notes: Mixtures and Contaminants

Real process fluids are rarely single chemicals. Trace components move material selections in both directions: a few parts per million of chloride in an otherwise benign stream can disqualify a stainless grade, while a trace oxidizer can stabilize a passive film. Waste streams and recirculated fluids deserve particular honesty in this block: if the composition varies or is incompletely known, say so, because "unknown, treat as aggressive" is a selectable answer, while an unreported surprise is not.

Physical Properties: The Numbers That Size the Pump

• Specific gravity. Scales shaft power directly and reduces self-priming height. A dense fluid at SG 1.8 nearly doubles the power demand of the same hydraulic duty on water, and a motor sized on water data overloads immediately.
• Viscosity. Affects pump efficiency, head, and NPSH. Above modest thresholds it also pushes the selection toward different speeds and impeller geometries, and at high values toward positive displacement designs entirely.
• Vapor pressure. Determines cavitation margin and flags volatile fluids that demand hermetic sealing. Hot fluids and low-boiling solvents both raise vapor pressure, and both consequences belong in the data.
• Solids content. Presence, particle size range, hardness, and concentration. This single field ejects most pump families: hard solids in a corrosive fluid move the selection to UHMWPE slurry pump construction before any other question is asked.
• pH. A quick cross-check on the chemistry block and a flag for extremes that narrow material and elastomer choices.

Operating Duty: What the Pump Must Do

Flow and Head

Flow rate, in cubic meters per hour, with normal and maximum values. Total head, in meters, calculated properly: static lift plus the friction losses of every meter of pipe, every valve, and every fitting in the line, at the design flow. The head figure is the most commonly wrong number in pump inquiries, almost always wrong in the same direction, static lift counted and friction forgotten, and it undersizes the pump before selection begins. Where the calculation is uncertain, provide the pipe layout, lengths, diameters, and fittings list, and let the manufacturer compute it.

Suction Conditions

State whether the installation is flooded suction, with the source above the pump, or suction lift, drawing from below it, and give the vertical distance from the lowest liquid level to the pump centerline. This field decides the priming method and feeds directly into the NPSH calculation. Also note whether the suction line drains between cycles, since that changes the priming requirement even in nominally flooded layouts.

Duty Cycle and Operation Pattern

Continuous or intermittent, starts per day, and seasonal variation. Duty cycle affects motor sizing, bearing life expectations, and speed selection, and it changes the maintenance regime the pump will need. A pump running twenty starts a day lives a different life than the same pump running continuously, and the selection should know which life it is being specified for.

Constraints and Environment: The Fields Everyone Forgets

Three blocks of data rarely make it into inquiries and regularly determine whether the selection survives contact with reality. Hazard classification: is the fluid toxic, volatile, flammable, or high-purity? This decides the sealing architecture outright, since hazardous fluids mandate magnetic drive zero-leakage designs regardless of hydraulics. Site conditions: ambient temperature range, altitude, which lowers atmospheric pressure and with it available NPSH and self-priming lift, indoor or outdoor installation, and any hazardous-area electrical classification. Utilities and standards: available voltage and frequency, required flange standards, and any industry-specific compliance requirements. None of these fields is exotic, and each one has sunk a selection that omitted it.

The Five Mistakes That Appear in Every Inquiry Season

Certain data sheet errors recur so reliably that experienced selection engineers check for them first. The head figure that covers only static lift, with friction losses uncounted, undersizes the pump and produces a unit that never reaches its flow. The fluid named without concentration, where "sulfuric acid" arrives with no percentage and the material selection has to be chased down before work can start. The worst case replaced by the average, where normal temperature and normal chemistry are reported but the hot cleaning cycle and the batch-end concentration spike are not, and the pump meets conditions it was never specified for. Solids described as "a little" or "occasionally," which is not data: particle size, hardness, and concentration decide between entire pump families, and a vague answer defers the most decisive question in the file. And the missing hazard flag, where a fluid's toxicity or flammability emerges only after a mechanically sealed pump has been proposed, forcing the selection back to the start. Every one of these mistakes is free to fix at the inquiry stage and expensive to fix after commissioning, which is the entire economic argument for the data sheet.

The Duty Data Sheet Template

Conclusion

The duty data sheet is the difference between a pump selected for your process and a pump selected for a guess. Complete chemistry, honest physical properties, a properly calculated head, real suction conditions, and the constraints everyone forgets: hazard class, altitude, and utilities. With these fields filled, a manufacturer can select, verify, and stand behind a recommendation; with any of them missing, the recommendation contains an assumption, and assumptions are what fail. YFTEL engineers review every inquiry against this structure across the full range of lined centrifugal chemical pumps, magnetic drive, self-priming, and slurry designs. Send us your duty data in this format, and we will return a verified selection with the reasoning documented.

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  YFTEL Pumps

  Fluid Engineers & Technical Support, YFTEL Pump

  YFTEL is a chemical pump manufacturer based in Hangzhou, China, with a 26,000 m² production base in Hangzhou, China, with a 26,000 m² production base in Anhui. Using the CAS-patented Fluoroplastic Alloy material, we produce 300+ models of corrosion-resistant pumps, valves and piping, exported to 30+ countries.