When a pump moves a toxic, flammable, or environmentally damaging liquid, the engineering question is rarely whether the containment boundary can be breached – every boundary can fail given the right initiator. What matters: how quickly is a breach detected, how much margin remains, and how much escapes before shutdown?
Our new white paper sets out a layered defense in depth framework, separating measures that merely limit and direct leakage (secondary control) from those that fully retain it (secondary containment) – from the simplest solution to the most robust: a sealless pump with a double containment system, continuously monitored, requiring no external utilities and achieving zero leakage to atmosphere.

Fresh out of painting and ready for delivery: three out of a total of 30 side channel pumps with magnetic drive for a petrochemical plant in China. The pumps are engineered for handling different chemicals like Di-Isobutene, C8 Hydrocarbons, Trimethylhexanal, 3-Methylhexanoic Acid or Valeraldehyde.

Our side channel pumps provide the following advantages:
🔹 Up to 8-stage pump design
🔹 Low-NPSH first stage for improved suction performance in challenging conditions on suction side and reduced cavitation risk
🔹 Magnetic drive for hermetically sealed, low-maintenance operation
🔹 Radial vane impellers made of duplex steel with DLC coating, combining corrosion resistance with high wear protection
🔹 Heavy duty barrel casing design as per standard providing only two gaskets for sealing against atmosphere -> regardless of the number of stages❗️

The combination of multi-stage hydraulics, robust design + materials and the leak-free drive technology makes this pump solution well-suited for handling such sensitive and demanding fluids.

Handling hydrofluoric acid (HF) is one of the most demanding challenges in petrochemical applications. For a plant in Germany, Klaus Union delivered a solution where material selection and manufacturing know-how took center stage.
HF requires absolute reliability and zero tolerances – both in terms of corrosion resistance and containment. Standard designs quickly reach their limits, especially when complex geometries are involved.

OUR SOLUTION 🔧
A taylor made single-stage centrifugal pump with magnetic drive (series SLM APL) acc. API 685 eliminating dynamic seals and providing a hermetically sealed system:
🔹 Full Alloy 400 design for outstanding resistance against hydrofluoric acid
🔹 Double volute casing – but instead of casting, manufactured as a precision welded construction
🔹 Hybrid double containment shell with inner PTFE-based lining
🔹 External flushing connection for inertization between batches

ADVANTAGES OF THE HYBRID DOUBLE CONTAINMENT SHELL 💡
🔹 Combination of metallic & non-metallic shell
🔹 Pressure rating: up to PN 63
🔹 Separate pressure integrity testing for inner and outer shell possible
🔹 Fully compliant with API 685
🔹 Reduced heat input to the pumped liquid
🔹 Maximum operational safety with less energy consumption
🔹The protection of positive double containment with an increase in eddy current loss of less than 8% compared to a single metallic shell of the same material

For a demanding biodiesel unloading application at one of the world’s largest tank terminal operators in southern Thailand, we supplied a single volute twin screw pump with mechanical seal (series DSP-2CO), strictly engineered and manufactured in accordance with API 676 (4th edition).

Twin screw pump technology is particularly well suited for terminal operations. Its inherently smooth and low-pulsation conveying principle ensures a stable and gentle flow, enabling safe and reliable fluid handling under the challenging operating conditions. At the same time, the Klaus Union DSP-2C pump series provides excellent self-priming and stripping capabilities – both critical requirements for an efficient unloading/loading process.

The Klaus Union design strongly focuses on robustness and operational reliability – key features that set our solution apart from many standard pump designs on the market:

🔹 Rotor chamber fully positioned below the suction and discharge flanges – the horizontally arranged screws as well as the mechanical seal remain always wetted, protecting them from dry running while also supporting superior self-priming and stripping performance
🔹 PN 25 casing as per standard for enhanced strength and durability
🔹 Replaceable bearing bushes with integrated standard lubrication grooves, suitable for both low and high viscosities while maintaining maximum efficiency (marked 🟡 in the sectional drawing)
🔹 Replaceable shaft sleeves protecting the screws in the bearing seat areas (marked 🔵 in the sectional drawing)
🔹 Replaceable shaft collars mounted on non-drive end, absorbing the residual axial loads and ensuring axial positioning of the rotors + simplifying maintenance and extending service life (marked 🟢 in the sectional drawing)
➕ many more…

The result is a pump solution designed to perform reliably and reduce downtime and OPEX to a minimum.

We would like to thank you for the good cooperation and the trust you placed in us in 2025.

We wish you a Merry Christmas, pleasant and peaceful holidays and a Happy New Year.

A great case to close the year: after 40 years of operation, a customer requested service support for two magnetic drive centrifugal pumps (series SLM N) – specifically two baseplates.
Not because of an issue with the pumps, but because they were fitted with new motors.

A strong example of durability and long-term serviceability.

This submerged centrifugal pump with magnetic drive series SLM NVT, designed with a 3.9 m immersion depth, is ready for shipment to a German refinery, where it will handle slop gasoline. The pump will replace a mechanically sealed pump, that had reached its limits when handling this particularly severe medium, where the solid content and fluid characteristics lead to high wear in the intermediate bearings and unsatisfactory meantime between maintenance.

Built in accordance with DIN EN ISO 2858 and DIN EN ISO 15783, and specifically engineered for demanding refinery service, the system is optimized for processing this difficult to handle liquid containing significant amounts of abrasive solids and a tendency to polymerize.

Key design features include:
🔹 Leak-free magnetic drive system, specially designed for high viscosities and high solid content
-> Equipped with a non-metallic containment shell made of zirconium oxide
-> This ensures no contact between process fluid and ambient air, reducing the polymerization properties of the liquid
🔹 Klaus Union NoVisco® bearings, offering exceptional reliability under challenging operating conditions
-> Extremely resistant to abrasive and erosive wear
-> Operates without a hydrodynamic lubrication film
-> No minimum fluid viscosity required
-> Retrofittable into existing Klaus Union pumps
🔹 Plug & Pump Retrofit Design
-> Fits into existing installation space
-> No need to modify any piping