Following recurring seal failures encountered by engineers of pumps and valves manufacturer KSB that could not easily be resolved by changing operating practices, the company is expanding its range of mechanical seals for its own pumps as well as introducing solutions suitable for a wide number of competitor pumps and third party applications.

KSB’s development of its own mechanical seal range stemmed from its continuous drive to improve pump performance and was the result of the development of one of KSB’s pump ranges.

The company has recently taken steps to develop and manufacture its own range of mechanical seals that are matched exactly to the purpose of different pumps using its global advanced manufacturing facilities. The seals are also produced to the same exacting standards as its equipment.

KSB is already producing a significant portion of the seals used in its new pumps and has recently started marketing its sealing solutions.

Because KSB knows and understands pump designs, KSB SupremeServ mechanical seals sales engineer Phumelela Ngcobo says the company has a detailed understanding of hydraulic performance, shaft behaviour, bearing arrangements and the operating conditions inside the seal chamber.

“That allowed our engineers to identify the root causes of the failures and develop sealing solutions specifically designed to overcome those challenges,” he explains.

Ngcobo notes that while KSB is renowned as a pump manufacturer, customers are still surprised to learn that the company also designs, manufactures and supports nearly every pump type with its own range of mechanical seals.

He explains that the roles played by mechanical seals are important for the reliable operation of many types of pumps, as their primary purpose is to prevent the pumped material from leaking along the rotating shaft and ensure that the fluid remains safely contained within the pump and is not leaking into the surrounding environment.

Presently, KSB’s seals range includes solutions for the vast majority of KSB pumps together with universal mechanical seals suitable for many competitor pumps brands.

The range includes component and cartridge mechanical seals available in both single and dual arrangements. It also comprises pump-specific sealing solutions, seals manufactured in accordance with the DIN EN 12756 standard, and API 682-compliant sealing systems for applicable process pumps, slurry application seals, boiler feed pump seals, high-pressure mechanical seals, and ATEX-certified sealing solutions for use in hazardous environments.

“Where a standard solution is unavailable, our engineering team will even develop custom sealing systems based on pump dimensions and detailed process information supplied by the customer,” says Ngcobo.

Complete Solution

A considerable advantage of manufacturing mechanical seals is the ability to offer customers complete sealing solutions from a single source, says KSB.

In addition to mechanical seals, KSB’s portfolio includes API 682-compliant seal support systems, piping plans, seal pots, heat exchangers, flow meters and associated instrumentation. Supplying these components as an integrated package ensures compatibility between the sealing equipment and the support system, simplifying procurement, installation, commissioning and ongoing maintenance while enhancing overall system reliability, reports KSB.

The company emphasises that every application is unique, and that the materials selected for a mechanical seal are carefully chosen to improve reliability under the specific operating conditions.

For general industrial duties, reaction bonded silicon carbide is often the preferred choice as it offers good wear resistance and reliable performance across a wide range of applications.

For more demanding services involving aggressive chemicals, elevated temperatures or higher operating pressures, KSB says sintered silicon carbide is typically specified owing to its corrosion resistance, higher mechanical strength and good performance under severe operating conditions.

“Carbon is widely used as a seal face material due to its excellent self-lubricating properties and low coefficient of friction, making it ideal for clean fluid applications across a range of industries including food and beverage processing.

“For more demanding operating conditions involving higher temperatures and pressures, antimony-impregnated carbon is often specified because of its improved mechanical strength, wear resistance and enhanced thermal conductivity,” says Ngcobo.

Where pumps handle abrasive slurries or fluids containing suspended solids, tungsten carbide is frequently selected for its hardness and resistance to abrasive wear that ensures reliable performance in severe service conditions.

“Standard metallic components are manufactured from 316L stainless steel, while highly corrosive applications may require upgraded materials such as super duplex stainless steel,” he says.

Secondary sealing elements are also carefully selected with elastomers specified according to the chemical compatibility and operating temperature of each application.

“There are many variables and it pays to deal with our team rather than to guess, because every seal is engineered using the most appropriate combination of materials for the customer’s operating conditions,” explains Ngcobo.

KSB’s mechanical seals are used across a wide spectrum of industries including mining, water and wastewater, petrochemical processing, power generation, pulp and paper production, chemical processing, food and beverage manufacturing and general industry, among others.

These are supported by KSB SupremeServ’s dedicated refurbishment facilities which repairs KSB and competitor mechanical seals.