Diaphragm Pumps
Diaphragm pumps use a flexing membrane to move fluid without it touching a rotating seal, the standard choice for corrosive, abrasive, or shear-sensitive liquids and hazardous-area chemical transfer. NLS sources air-operated double-diaphragm (AODD) pumps in metal and non-metal bodies, ATEX/IECEx rated where required, for chemical transfer and industrial fluid handling on Saudi sites.
An air-operated double-diaphragm pump, the type NLS quotes most for general industrial duty, uses compressed air to drive two flexible diaphragms back and forth in opposition, each one alternately pulling fluid in and pushing it out through a set of check valves. There's no rotating shaft seal anywhere in the wetted path, no electric motor near the fluid, and no close-tolerance rotating parts that abrasive solids can grind against, which is exactly why this pump type gets specified where a centrifugal or gear pump would fail quickly.
That construction gives diaphragm pumps three practical advantages a project spec usually cares about. They run dry without damage, useful on tank stripping and drum unloading where the last of the fluid runs out before the operator shuts the pump off. They self-prime and tolerate suction lift a centrifugal pump can't manage. And because they're air-driven rather than electric, they're inherently suited to hazardous areas once fitted with ATEX or IECEx rated air-control components, no motor sparking risk to engineer around. NLS sources bodies in polypropylene, PVDF, or aluminum and stainless steel depending on the chemical's compatibility and the duty's abrasion level, with elastomer diaphragm options (PTFE, Santoprene, or nitrile) matched to the fluid.
On Saudi sites, diaphragm pumps handle chemical transfer between tanks and totes, construction and process dewatering where the water carries grit or debris, and general industrial fluid handling, paint, resin, or wastewater sludge, where a centrifugal pump's tight impeller clearance would clog or wear out fast. Where the standard applies, API 675 covers the accuracy and reliability practice for positive-displacement pumps used in chemical injection duty, though most diaphragm pump selection in general transfer service runs on the pump manufacturer's own performance data rather than a formal process standard.
NLS quotes diaphragm pumps against the fluid (chemical compatibility and any solids content), the required flow rate, and whether the installation sits in a classified hazardous area, since that last point determines whether ATEX or IECEx rated air-control hardware needs to be built into the package from the start rather than added later.
Specifications
- ✓Configuration: air-operated double-diaphragm (AODD) pump
- ✓Body material options: polypropylene, PVDF, aluminum, and stainless steel
- ✓Diaphragm/elastomer options: PTFE, Santoprene, and nitrile matched to fluid compatibility
- ✓Hazardous-area option: ATEX/IECEx rated air-control components for classified areas
- ✓Sizing basis: fluid chemical compatibility, solids content, required flow rate, suction lift
- ✓Typical use: chemical transfer, tank/drum unloading, construction and process dewatering, industrial fluid handling
Frequently Asked Questions
Why choose a diaphragm pump over a centrifugal pump for chemical transfer?+
A diaphragm pump has no rotating shaft seal in the wetted path, which removes the main leak point a centrifugal pump has on corrosive or hazardous chemicals. It also runs dry without damage and self-primes, useful for tank stripping and drum unloading where a centrifugal pump would lose prime.
Can a diaphragm pump be used in a hazardous, classified area?+
Yes, since it's air-driven rather than electric, it avoids the motor spark risk an electric pump carries. Fitting ATEX or IECEx rated air-control components makes it suitable for the classified area; NLS confirms the area classification before specifying the air-control package.
What determines the body material for a diaphragm pump?+
The fluid's chemical compatibility and abrasion level. Polypropylene and PVDF suit most acids and general chemicals, aluminum covers non-aggressive industrial fluids at lower cost, and stainless steel handles abrasive or higher-temperature duty. The diaphragm and check-valve elastomer material get matched separately to the same fluid data.