Jim Tallia | ThermOmegaTech

| IMAGE 1: Thermostatic valves automatically control seal flush water to protect mechanical seals, reduce water usage and improve pump efficiency. (Image courtesy of ThermOmegaTech)

Mechanical seals are a critical part of many industrial systems that rely on pumps and mixers to process materials, preventing leakage while protecting rotating equipment from contamination and wear.

These seals require adequate cooling and lubrication to operate reliably. Without proper temperature control, seals can overheat. Conversely, excessive cooling can increase fluid viscosity, reduce system efficiency and place additional strain on rotating equipment.

Many facilities address these concerns by supplying a continuous flow of cooling media to the mechanical seal. While effective at preventing overheating, this approach consumes far more water than necessary.

Mechanical seal flush serves several important purposes:

Removes heat from the seal faces
Lubricates the sealing surfaces
Prevents contamination
Flushes away debris

Limitations of Traditional Seal Water Control

Many seal support systems supply cooling water continuously regardless of operating conditions. Once the seal reaches a safe operating temperature, much of that water flows directly to drain without providing additional cooling. The results can include excessive water use, higher wastewater treatment costs, increased operating expenses, premature seal failures and unnecessary maintenance.

For facilities operating dozens or even hundreds of pumps, these inefficiencies can quickly multiply. Operators have historically relied on manual valves or fixed-flow arrangements to provide cooling water to seals. While these methods are simple, they usually deliver more cooling water than necessary because they cannot respond to changing operating conditions.

Traditional approaches can present several drawbacks:

Continuous water discharge to drain
Dependence on manual operator adjustment
Inconsistent seal temperatures
Increased potential for seal damage
Excessive water consumption

Because process conditions fluctuate, a fixed flow rate rarely provides the optimum amount of cooling throughout operation.

Temperature-Based Control

One approach is to regulate water flow based on actual seal temperature rather than maintaining a constant flow. Installed on the seal water outlet, thermostaticseal support valves continuously monitor the temperature of the water leaving the seal cavity.

When the water temperature exceeds a predetermined set point, the valve modulates open to discharge heated water (which can be collected for another use), allowing cooler water to enter the seal chamber. As temperatures return to acceptable levels, the valve modulates closed.

Self-actuating thermostatic valves require no external power, sensors or controllers. By automatically regulating cooling water based on outlet temperature, they help prevent overheating, reduce dry-running conditions, extend seal life and lower operating costs while reducing water consumption.

| IMAGE 2: Sugar production facility (Image credit: mailsonpignata - stock.adobe.com)

Temperature-Based Control

One approach is to regulate water flow based on actual seal temperature rather than maintaining a constant flow. Installed on the seal water outlet, thermostaticseal support valves continuously monitor the temperature of the water leaving the seal cavity.

When the water temperature exceeds a predetermined set point, the valve modulates open to discharge heated water (which can be collected for another use), allowing cooler water to enter the seal chamber. As temperatures return to acceptable levels, the valve modulates closed.

Self-actuating thermostatic valves require no external power, sensors or controllers. By automatically regulating cooling water based on outlet temperature, they help prevent overheating, reduce dry-running conditions, extend seal life and lower operating costs while reducing water consumption.

Water Savings in Practice

In a recent case study, a major United States sugar producer faced high maintenance costs and excessive water use associated with its seal arrangements. After installing thermostatic seal support valves on double mechanical seals, the facility eliminated seal failures caused by dry running.

The reduction in water consumption was substantial. While seal manufacturers recommended approximately 2.6 gallons per minute for cooling, the thermostatically controlled system required only approximately 3 gallons per hour under operating conditions.

Assuming 2,080 operating hours annually, water usage was reduced from approximately 324,480 gallons per year to just 6,240 gallons per year, saving more than 318,000 gallons annually for each mechanical seal equipped with temperature-based control.

Benefits Beyond Water Conservation

Reducing water demand with thermostatic seal support valves can deliver operational benefits in addition to environmental advantages. Temperature-controlled seal support systems can:

Extend seal life by maintaining proper operating temperatures and minimizing thermal damage.
Reduce maintenance costs by preventing dry running and overheating.
Improve equipment reliability through automatic, self-regulating operation that eliminates manual valve adjustments and operator oversight.
Lower wastewater treatment costs by reducing the amount of water discharged to drains.

For many facilities, these combined operational savings exceed the value of water conservation alone. By improving seal temperature control, facilities also can reduce one of the leading causes of pump downtime, resulting in greater reliability and lower maintenance costs.

Temperature-based seal water control enables facilities to reduce water consumption without sacrificing seal performance. By supplying cooling water only when operating conditions require it, thermostatic valves improve pump reliability, lower operating costs and support long-term sustainability initiatives.

As manufacturers continue seeking ways to improve operational efficiency while conserving valuable resources, thermostatic seal support valves offer a solution that benefits both the bottom line and the environment.

Jim Tallia, PE, DBA, is the vice president of sales and marketing at ThermOmegaTech. He has extensive experience in pumping solutions for a wide range of industrial applications and holds a professional engineer license, a BE and ME in mechanical engineering, an MBA and a doctorate in business administration. For more information, visit thermomegatech.com.

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