Product Lines

- Mechanical Seal Pumps • WMSA-API Pumps

HIGH EFFICIENCY NON-METALLIC PROCESS PUMPS
High thickness, machined billet construction withstands severely corrosive and penetrating process liquids. Far more durable than linings or coatings, machined thermoplastics resist swelling and permeation for long-term reliability and extended service life. Non-metallic liquid ends avoid unpredictable corrosion with alloy pumps that require costly and constant maintenance. Optimized hydraulic efficiencies provide energy savings along with extended pump lifecycle. Go to our Models page here.

Mechanical seal pumps use precision sealing components to control fluid leakage at the point where the rotating pump shaft passes through the stationary pump casing. A rotating seal face and stationary seal face remain in close contact under controlled spring and hydraulic pressure, creating an effective barrier between the process liquid and the surrounding environment. Seal faces may be manufactured from silicon carbide, tungsten carbide, carbon graphite, or other application-specific materials. Selecting the right face materials, elastomers, and pump construction is essential when handling corrosive chemicals, abrasive liquids, elevated temperatures, or demanding continuous-duty services.

Compared with traditional packed pumps, mechanical seal pumps provide better leakage control, reduced shaft wear, less routine adjustment, and lower friction. Warrender combines these benefits with corrosion-resistant non-metallic pump construction for demanding chemical-processing applications.

Warrender mechanical seal pumps are available in solid polypropylene, PVDF, reinforced thermoplastic, and FRP constructions. Available designs include ANSI and ISO centrifugal process pumps and high-capacity axial-flow pumps with capacities up to 14,000 GPM.

Need help selecting a pump? Contact Warrender at 847-247-8677 or sales@warrender.com

High-Efficiency Non-Metallic Mechanical Seal Pumps

Warrender mechanical seal pumps are engineered for process liquids that can rapidly attack conventional metallic, lined, or coated pumps. Thick-section, machined thermoplastic and FRP construction provides corrosion resistance throughout the liquid end—not merely at its surface.

Because the corrosion-resistant material extends through the pump component, minor surface damage does not immediately expose an incompatible base metal. This makes a solid non-metallic pump particularly valuable when handling aggressive or penetrating chemicals.

Key advantages include:

• Solid polypropylene, PVDF, reinforced thermoplastic, and FRP constructions
• ANSI B73.1 and ISO 2858 configurations
• Centrifugal and axial-flow hydraulic designs
• Flow capacities ranging up to 14,000 GPM
• Resistance to corrosive and penetrating process liquids
• Reduced dependence on expensive specialty alloys
• Replaceable mechanical seal components
• Efficient hydraulic designs for demanding industrial service
• More than 50 years of industrial pump experience
  
  

What Is a Mechanical Seal Pump?

A mechanical seal pump is a pump that uses an end-face seal around its rotating shaft to limit the escape of process fluid. The mechanical seal is installed between the rotating shaft and stationary casing, typically within a dedicated seal chamber.

During operation, one seal face rotates with the shaft while the opposing face remains stationary. Springs and process pressure keep the two precisely finished faces together. A microscopic film of liquid between them provides lubrication and helps control heat while the faces restrict outward leakage.

Secondary sealing elements, such as O-rings, gaskets, or bellows, prevent leakage around the primary seal faces. The precise configuration depends on the pumped liquid, temperature, pressure, shaft speed, solids content, and required level of containment.

How Does a Pump Mechanical Seal Work?

A mechanical seal must perform two jobs at the same time: permit the pump shaft to rotate and prevent the process liquid from escaping through the shaft opening.

The principal components normally include:

• Rotating seal face: Turns with the pump shaft.
• Stationary seal face: Remains fixed within the seal gland or housing.
• Spring mechanism: Maintains contact between the sealing faces.
• Secondary seals: O-rings, gaskets, or bellows that seal around stationary and moving components.
• Seal gland: Positions and supports the seal assembly.
• Liquid film: Lubricates and cools the contacting faces during operation.

A properly selected mechanical seal allows only the extremely small amount of fluid necessary to lubricate the faces. Excessive visible leakage can indicate worn faces, incorrect installation, dry running, misalignment, chemical incompatibility, or operation outside the pump’s intended range.

Benefits of Mechanical Seal Pumps

Improved Leakage Control

Mechanical seals provide much better control of process-fluid leakage than conventional compression packing. Better containment can reduce product loss, keep surrounding equipment cleaner, and improve workplace conditions.

Reduced Shaft Wear

Packing contacts the shaft or shaft sleeve and can cause wear over time. Mechanical seals concentrate the dynamic sealing action between replaceable, precision-lapped faces, helping protect the pump shaft.

Less Routine Adjustment

Packed pumps may require periodic tightening to maintain the desired leakage rate. A correctly installed mechanical seal generally operates without frequent manual adjustment.

Lower Friction

Mechanical seals normally create less shaft friction than tightly compressed packing. Reduced friction can decrease power loss and unnecessary heat generation around the shaft.

Broad Application Flexibility

Mechanical seal designs can be configured for numerous fluids, temperatures, pressures, and operating conditions. Face materials, elastomers, metallurgy, and seal arrangements should always be matched to the specific service.

Serviceable Construction

When wear eventually occurs, the seal can normally be inspected or replaced without replacing the complete pump. Ready access to maintenance personnel and replacement components makes mechanical seal pumps practical for many industrial facilities.

Warrender Mechanical Seal Pump Models

WCDI and WCDA Solid PP and PVDF Pumps

WCDI and WCDA mechanical seal pumps feature solid polypropylene or PVDF thermoplastic liquid ends. They are available in ISO 2858 and ANSI B73.1 configurations and offer flow capacities up to 10,000 GPM.

These pumps are intended for high-flow industrial processes in which chemical compatibility and corrosion resistance are primary considerations.

WCDI-R and WCDA-R Reinforced Thermoplastic Pumps

WCDI-R and WCDA-R pumps use reinforced solid polypropylene or PVDF construction for demanding process applications. ANSI B73.1 and ISO 2858 configurations are available, with capacities up to 10,000 GPM. The reinforced construction provides an option for applications requiring corrosion resistance combined with additional structural support.

WCFG FRP Fiberglass Pumps

WCFG mechanical seal pumps use FRP fiberglass construction and are designed to ANSI B73.1 dimensional standards. Available capacities extend to 6,600 GPM. These pumps provide an alternative to metallic equipment for compatible corrosive chemical services and high-flow industrial processes.

WCGI-A and WCGA-A Armored Thermoplastic Pumps

WCGI-A and WCGA-A pumps combine solid polypropylene or PVDF liquid ends with an armored construction. They are available in ISO 2858 and ANSI B73.1 configurations, with flow capacities up to 10,000 GPM. The armored design adds exterior support while retaining non-metallic wetted components for chemical compatibility.

WCGK Axial-Flow Pumps

WCGK reinforced polypropylene axial-flow pumps are designed for applications requiring extremely high circulation rates at relatively low differential heads. Flow capacities extend to 14,000 GPM.

Typical uses include chemical circulation, evaporation, crystallization, and other high-volume process services where corrosion-resistant construction is needed.

Common Mechanical Seal Pump Applications

Warrender mechanical seal pumps can be considered for compatible applications involving:

• Acids and alkaline solutions
• Chemical transfer and circulation
• Corrosive process liquids
• Plating and metal-finishing solutions
• Chemical manufacturing
• Scrubber circulation
• Wastewater treatment
• Pickling and surface-treatment systems
• Evaporator and crystallizer circulation
• Fertilizer and agricultural chemicals
• Pulp and paper processing
• General industrial fluid transfer

Final pump and seal selection must be based on the actual chemical concentration, operating temperature, pressure, solids content, viscosity, flow rate, required head, and system conditions.

Mechanical Seal Face Materials

The correct seal-face combination is critical to reliability.

Carbon Graphite

Carbon graphite offers low friction and useful self-lubricating characteristics. It is commonly paired with a harder mating face, but its chemical compatibility and suitability must be evaluated for the particular liquid.

Silicon Carbide

Silicon carbide provides excellent hardness, wear resistance, temperature capability, and broad chemical resistance. It is frequently considered for corrosive liquids and services containing limited amounts of abrasive material.

Tungsten Carbide

Tungsten carbide offers high strength and resistance to mechanical wear. Its suitability depends on the chemical environment and the binder used in the material.

Elastomers and Secondary Seals

O-rings and other secondary seals must also be compatible with the process liquid. Common elastomer families include EPDM, FKM, and PTFE-based materials, but no material should be selected without reviewing the complete operating conditions.

Single Versus Double Mechanical Seals

A single mechanical seal uses one primary sealing interface between the process liquid and atmosphere. It is often appropriate when the liquid is compatible with the seal materials and limited leakage does not create an unacceptable safety or environmental risk.

A double mechanical seal uses two sets of sealing faces and a barrier or buffer fluid between them. This arrangement may provide additional containment or lubrication for hazardous, abrasive, crystallizing, or poorly lubricating liquids. It also requires additional support equipment and monitoring.

The best arrangement depends on the liquid, emissions requirements, operating pressure, temperature, reliability objectives, and maintenance capabilities of the facility.

Mechanical Seal Pumps Versus Sealless Magnetic Drive Pumps

Mechanical seal pumps and sealless magnetic drive pumps address different operating priorities.

A mechanical seal pump is often a practical choice when:

• The process liquid presents a manageable leakage risk
• Maintenance personnel can inspect and replace seals
• A standard ANSI or ISO pump configuration is preferred
• The application requires large flow capacity
• Initial equipment cost is an important consideration

A sealless magnetic drive pump may be preferable when:

• Zero external leakage is required
• The liquid is toxic, hazardous, or extremely valuable
• Mechanical seal maintenance must be eliminated
• Emissions regulations require a higher level of containment
• Process contamination from seal leakage cannot be tolerated

Warrender manufactures both mechanical seal and sealless pump designs, allowing the selection to be based on the application instead of forcing every process into one pump technology.

How to Select a Mechanical Seal Pump

Accurate application information is essential when choosing a pump, construction material, and seal arrangement. Before requesting a recommendation, gather the following:

• Required flow rate
• Total dynamic head or discharge pressure
• Liquid name and chemical concentration
• Operating and maximum temperature
• Specific gravity
• Viscosity
• Solids type, size, and concentration
• Suction pressure and available NPSH
• Continuous or intermittent duty
• Preferred connection and dimensional standard
• Motor and electrical requirements
• Indoor or outdoor installation
• Hazardous-area classification
• Acceptable level of leakage
• Applicable environmental or plant standards

Providing these details helps avoid chemical incompatibility, cavitation, inadequate performance, premature seal wear, and unnecessary energy consumption.

What Causes Mechanical Seal Failure?

Mechanical seals often fail because of operating conditions rather than a manufacturing defect. Common causes include:

• Running the pump dry
• Inadequate seal-face lubrication
• Incorrect seal or elastomer materials
• Shaft misalignment
• Excessive vibration
• Cavitation
• Abrasive solids
• Crystallization around the seal faces
• Excessive temperature or pressure
• Improper installation
• Operating too far from the pump’s recommended range
• Starting the pump against incorrect valve conditions

A complete review of the pump, seal, piping, and operating procedure is usually more valuable than repeatedly replacing the failed seal.

Mechanical Seal Pump Maintenance

Mechanical seals do not normally require the routine adjustment associated with packing, but the pump should still be monitored. Maintenance personnel should regularly check for visible leakage, unusual noise, vibration, elevated bearing temperature, pressure changes, and changes in motor load.

Never allow a liquid-lubricated mechanical seal to operate dry unless the pump and seal are specifically designed for dry-running service. Before maintenance, isolate the pump, disconnect and lock out its power source, relieve system pressure, drain the equipment safely, and follow the plant’s procedures for the pumped chemical.

Why Choose Warrender?

Since 1975, thousands of Warrender pumps have been placed in service worldwide. Warrender supplies mechanical seal and sealless pumps for demanding chemical-processing and industrial applications.

Warrender mechanical seal pump options include:

• Solid polypropylene and PVDF pumps
• Reinforced and armored thermoplastic pumps
• FRP fiberglass process pumps
• ANSI B73.1 and ISO 2858 configurations
• Centrifugal capacities up to 10,000 GPM
• Axial-flow capacities up to 14,000 GPM
• Application-specific pump and material selection
• Mechanical seal and sealless alternatives

Our goal is to match the pump technology, materials, hydraulics, and sealing arrangement to the actual service conditions.

Frequently Asked Questions About Mechanical Seal Pumps

What is a mechanical seal pump?

A mechanical seal pump uses a rotating and stationary seal face to control leakage where the rotating shaft enters the pump casing. It offers better leakage control and normally requires less adjustment than traditional packing.

Are mechanical seal pumps completely leak-free?

Mechanical seals are designed to control leakage to an extremely low level, but they should not automatically be described as completely leak-free. Applications requiring zero external leakage may be better suited to a sealless magnetic drive pump.

What is the best mechanical seal for a chemical pump?

There is no universal best seal. Selection depends on chemical compatibility, concentration, temperature, pressure, lubricity, solids content, shaft speed, and required containment. The seal faces, elastomers, and pump materials must be evaluated together.

Can a mechanical seal pump handle corrosive chemicals?

Yes, when the pump construction, seal faces, and secondary seals are compatible with the liquid. Warrender offers polypropylene, PVDF, reinforced thermoplastic, armored thermoplastic, and FRP pump configurations for compatible corrosive services.

What is the difference between a mechanical seal and pump packing?

Packing uses compressed rings around a shaft or sleeve and usually permits controlled visible leakage. A mechanical seal uses precision-lapped faces to provide much tighter leakage control with less shaft friction and less routine adjustment.

When should I use a double mechanical seal?

A double seal may be appropriate for hazardous, abrasive, crystallizing, poorly lubricating, or high-consequence fluids. The arrangement requires a properly designed barrier or buffer system and should be selected by an experienced engineer.

How long does a pump mechanical seal last?

Seal life depends on correct selection, installation, alignment, operating conditions, and maintenance. Dry running, cavitation, vibration, incompatible materials, and operation outside the pump’s intended range can shorten service life dramatically.

Should I choose a mechanical seal or magnetic drive pump?

Choose based on the fluid and containment requirement. Mechanical seal pumps can provide economical, serviceable performance for many industrial processes. Magnetic drive pumps are generally preferred when zero leakage, toxic-emissions control, or elimination of seal maintenance is the primary objective.

Request a Mechanical Seal Pump Recommendation

Send Warrender your required flow, total dynamic head, liquid composition, concentration, temperature, specific gravity, viscosity, solids information, suction conditions, motor requirements, and installation details. Our team can help evaluate the appropriate mechanical seal pump, construction material, and hydraulic configuration.

Call 847-247-8677, email sales@warrender.com, or submit a pump request through Warrender’s online RFQ form.

Mechanical Seal Pumps for Corrosive Chemical Processing

What is a Non-Metallic Mechanical Seal Pump?

A non-metallic mechanical seal process pump is an industrial pump designed to safely and efficiently transfer corrosive, abrasive, or demanding process liquids while preventing leakage through the use of a precision mechanical seal. High-efficiency non-metallic mechanical seal process pumps feature high-thickness, machined billet construction that withstands severely corrosive and penetrating chemicals, offering far greater durability than lined or coated alternatives. The machined thermoplastic liquid end resists swelling and permeation, providing long-term reliability and extended service life. By eliminating metallic wetted components, these pumps avoid the unpredictable corrosion common with alloy pumps, reducing maintenance requirements and operating costs. Combined with optimized hydraulic efficiencies, they deliver reliable performance, lower energy consumption, and extended pump life, making them an ideal solution for the most demanding chemical processing applications. See more about what a mechanical seal pump is.