
What Are Calibration Columns?
A Calibration Column is a clear, graduated cylindrical vessel installed in the suction or discharge line of a chemical dosing pump.
By isolating the pump and timing how long it takes to draw down (or fill) a known volume marked on the column, operators can calculate the exact flow rate in gallons per hour (GPH), liters per hour (LPH), or milliliters per minute.
The column body is typically made from clear PVC, or acrylic for excellent visibility. The critical component is the end caps (top and bottom fittings), which determine chemical compatibility, pressure rating, and ease of installation. End caps are available in three primary materials: CPVC, and PTFE, each offering distinct advantages depending on the process fluid, pressure, and temperature requirements.
Key Benefits of Calibration Columns
| Accurate Pump Calibration | Provides direct visual measurement of actual pump output — far more accurate than relying on pump stroke settings alone. |
| Simple & Fast Verification | No need for scales, flow meters, or complicated test equipment. Just time the draw-down with a stopwatch. |
| Versatile End Cap Selection | CPVC and PTFE end caps allow perfect material compatibility for any chemical being pumped. |
| Permanent or Portable Use | Can be permanently installed in the pump suction line or used as a portable calibration tool. |
End Caps
Choosing the right material is critical for chemical compatibility, temperature resistance, and long-term performance.
| Material | Key Characteristics | Best Applications |
|---|---|---|
PVC![]() |
Excellent corrosion resistance to acids, bases, and salts. Cost-effective. Max temp: ~60°C (140°F) | Water treatment, mild chemicals, wastewater, pH adjustment, general industrial use |
CPVC |
Higher temperature resistance than PVC. Good chemical resistance. Max temp: ~93°C (200°F) | Hot water treatment, higher temperature chemical processes, industrial cooling systems |
PTFE |
Outstanding chemical resistance to nearly all acids, solvents, and bases. Non-stick surface. Max temp: ~260°C (500°F) | Highly corrosive chemicals, pharmaceutical, semiconductor, strong acids & solvents |
PVDF |
Excellent chemical resistance, high purity, superior mechanical strength & UV resistance. Max temp: ~150°C (302°F) | Aggressive acids, high-purity applications, pharmaceutical, food-grade, halogenated chemicals |
Need help selecting the right material for your application? Contact our team for expert recommendations tailored to your process conditions.

















CPVC
PTFE
PVDF





