Duty & liquid
Suitability
0 for clean liquids
Awaiting Valid Duty Parameters
Adjust the parameters on the left to compute live hydraulic values, ranges, and sizing verdicts.
Mag-drive pump failed again?
Dry running and bushing wear are the classic killers. We repair and re-build PP and PFA mag-drive pumps with the protection the duty needs.
Magnetic drive pumps explained
Why go sealless
A magnetic drive pump has no shaft seal: the impeller is driven through a containment shell by magnets, so there is no leak path. For acids, solvents and hazardous chemicals that is the whole point — no seal to fail, no vapour to escape. The cost is a set of constraints the sizing must respect.
The calculator sizes the duty normally — flow, head, SG to power and motor — then checks the constraints that decide whether a mag-drive pump is even the right answer.
The three killers
Dry running: with no process liquid, the internal bushings run dry and the magnets overheat — failure in minutes. Mandatory protection is a flow switch or low-level interlock; the calculator flags it every time. Solids: hard particles grind the bushings, so clean liquids only — a suction strainer is standard. Heat: friction in the bushings raises the liquid temperature, so hot, viscous or near-boiling duties need care and a real NPSH margin.
Temperature decides the build: PP up to about 80 °C, PFA lined beyond — the calculator picks the build from your temperature and density.
When to choose something else
Mag-drive pumps are the wrong answer for slurry, crystallizing liquids, and duties where dry running is unavoidable. For those, open-impeller centrifugal or diaphragm pumps win. Teflow manufactures PP and PFA mag-drive pumps and repairs both — call +91 98251 62709 for a duty review and rebuild quote.
Technical & Operational FAQs
Q1.What is a magnetic drive pump?
A sealless pump where the impeller is driven through a containment shell by magnets — no shaft seal, so nothing to leak. Standard for hazardous and corrosive chemicals where seal leakage is unacceptable. The trade-off: clean liquids only, no dry running, and temperature limits.
Q2.Why do magnetic drive pumps fail?
Dry running destroys bushings and magnets in minutes, hard solids grind the internals, and overheating from friction or hot liquids cooks the magnets. All three are preventable: fit flow/level protection, keep liquids clean, and respect temperature and NPSH limits.
Q3.Can a mag-drive pump run dry?
No — running dry for even a few minutes typically damages the internal bushings and magnets beyond repair. A flow switch or low-level interlock is mandatory protection, and the calculator flags it on every result.
Q4.PP or PFA mag-drive pump?
PP builds suit moderate chemicals up to about 80 °C. PFA lined builds handle hot acids, strong oxidizers and higher temperatures (up to ~180 °C), and are the choice for dense or aggressive duties. The calculator suggests the build from your temperature and liquid.
Q5.Do mag-drive pumps need NPSH margin?
Yes — more than sealed pumps. Internal friction heats the liquid, raising vapour pressure inside the pump, so a margin of 1.5 m or more above NPSHr is recommended. The calculator warns when the entered NPSHa falls below that.
Related Engineering Tools
Chemical Pump Sizing
NPSH Available Calculator
Compatibility Selector
Magnetic Drive Pumps
PP Mag-Drive Repair
Dry-Run Guide
Need a custom hydraulic audit or specific duty curve verification? Call +91 98251 62709 or Request a Detailed Engineering Quote.