Skip to content


In any pumping system, the mechanical seal is among the most essential components, safeguarding the motor against any leakage from the pump mechanism. As with any mechanical system where water is involved, a pump system must be designed to keep moisture away from any electrical components. Even a minuscule leak can destroy a pump over time by corroding elements to the point of failure. Once moisture reaches the motor, failure is imminent.

Casings, sleeves and bearings will likely show signs of corrosion before the more critical components are affected by leakage. While shaft seal failure is the most common cause of pump failure, a pump seal that is professionally designed and installed, properly maintained, and periodically replaced can keep any pump system running, leak-free, indefinitely.


Mechanical seals are critical components of industrial pumping infrastructure. Using the appropriate mechanical seal can increase reliability and significantly reduce downtime. The added advantage is the reduced product loss associated with poor sealing dynamics. Mechanical seals replace widely used gland packing to provide a more stable leak-resistant environment. A mechanical seal also helps eliminate the failure modes associated with gland packing, wear and damage to the shaft, excessive process leakage, and friction on the operating components. Using the right mechanical seal can reduce the shaft damage associated with gland packing.

Mechanical seals can significantly reduce the consumption of barrier fluids, increasing the Overall Equipment Effectiveness (OEE), and improving reliability.

Depending on the type of pump and process variables, there are various sealing devices to choose from. Mechanical seal designs are customized for the variables and characteristics of the fluid being pumped and the operational conditions of each process.


Stein Seal Industries has developed API (American Petroleum Institute) 682 seals for the oil and gas industry. Stein Seal has designed, manufactured and tested a Type A pusher seal, Arrangement 3, dual pressurized cartridge seal for this market. In an Arrangement 3 design, the barrier fluid pressure is kept higher than the seal chamber pressure and is designed to handle and contain hazardous and light hydrocarbon fluids. The process end face (inner) seal is specially balanced to handle reverse pressures, while the atmospheric end (outer) seal will contain the barrier fluids.

The Stein Seal Type A pusher seal is also available in Arrangements 1 and 2. An arrangement 1 seal is a single contacting wet cartridge seal with a bushing. Arrangement 2 cartridge seal is the same configuration as the Arrangement 3 seal but is an un-pressurized dual seal where the barrier fluid pressure is kept lower than the seal chamber fluid pressure. The atmospheric end (outer) seal will provide additional containment of hazardous fluids.

Stein manufactures API-certified and API-style pump and equipment seals, including multi-spring balanced, rotary-welded metal bellows, and single-spring seal assemblies.


Non-pusher seals are used in elevated temperatures and conditions that foul due to slurry packing or exposure to thick or viscous product. Polymer, elastomeric, and metal bellows shield the seal faces from contamination.

Pusher seals are often used at higher operational pressures. These increased pressures and heavy spring loading can lead to increased wear characteristics.

Cartridge seals are pre-assembled mechanical seals where faces and internal components are retained in a holder. Cartridge seals can be single, double or tandem, depending on design requirements.

Conventional seals are designed for simpler applications, such as water and food products.

Gas barrier seals are designed to be pressurized with an inert gas replacing the buffering fluid and the barrier support system.

Stein Seal Industries seals designed for the oil and gas industry are built, and qualification tested according to the rigorous API 682 test protocols.

With over 65 years of seal design, manufacturing and testing for the industrial and aerospace markets, the Stein Company has the experience to solve your sealing problems. Stein Seal Industrial provides sealing solutions to meet customer needs.

Please contact Stein Seal Industrial Industries directly to discuss a specific application or for more information.