High-Temperature Sponge Cleaning Balls – Types RT / RTL

Typical Applications

RT and RTL sponge cleaning balls are designed for use in online tube cleaning systems operating at temperatures up to 140°C or higher, making them particularly suitable for MSF (Multi-Stage Flash) desalination plants and other high-temperature industrial heat exchanger applications.

Other sponge ball types are available for special operating conditions and specific applications.

Available Sizes

RT sponge cleaning balls are available in standard diameters ranging from 15 mm to 45 mm, in 1 mm increments.

The standard specification is medium hardness. Non-standard diameters and hardness grades are available upon request.

Material Composition

RT sponge cleaning balls are manufactured from a specially formulated natural rubber compound containing inert fillers, with a filler-to-rubber ratio of approximately 1:2.

The compound contains approximately 10–20% vulcanizing agents, and its composition has been carefully optimized to provide the best balance between:

• Mechanical properties
• Service life
• Cleaning performance

The material is non-hazardous, and all ingredients used are approved for food-contact applications.

The pigments used to achieve the standard ball colours do not affect the physical or cleaning properties of the balls.

Colour Identification

Standard colours are:

• RT:Blue
• RTL (Light Density):Light Blue

Specific Gravity

The typical specific gravity of the cleaning ball material is approximately 0.27 g/cm³.

Water Saturation and Settling Characteristics

Before use, the balls should be fully saturated with water by repeatedly compressing them under water to remove all trapped air.

To ensure effective cleaning of every tube, the saturated ball should have a specific gravity close to that of the cooling medium.

Typical settling velocities are:

• Standard Balls (RT):6–8 cm/s
• Light-Density Balls (RTL):1–3 cm/s

Resistance to Cooling Water

RT sponge cleaning balls have been specifically developed for desalination plants and other high-temperature cooling water applications.

Although certain chemicals, such as petroleum products and other hydrocarbons, may adversely affect the ball material when present in significant concentrations, such contaminants are rarely encountered in cooling water systems.

Consequently, RT sponge cleaning balls provide excellent resistance to virtually all types of cooling water.

Cleaning Performance

RT sponge cleaning balls effectively remove the soft deposits commonly encountered in desalination systems, including:

• Mud
• Slime
• Magnesium oxide deposits
• Other soft fouling

They also help reduce the formation of hard scale by removing the initial crystal nuclei from which deposits such as calcium carbonate develop.

Once hard scale has become established, however, sponge cleaning balls alone are generally no longer effective.

Within practical operating limits, cleaning performance is not significantly affected by either:

• Ball oversizing (the difference between the ball diameter and the tube inside diameter), or
• Ball hardness.

However, the ball diameter should always be slightly larger than the inside diameter of the tube to ensure effective cleaning.

The maximum permissible oversize depends on:

• The allowable pressure drop across the heat exchanger, and
• The need to prevent the ball from becoming lodged inside the tube.

Ball Service Life

The service life of RT sponge cleaning balls depends primarily on:

• Cleaning frequency
• Tube surface condition
• Operating conditions

Under normal operating conditions, the typical service life is approximately four weeks, although considerably longer service life may be achieved depending on site conditions and cleaning frequency.

Scaled, roughened or corroded tube surfaces significantly accelerate ball wear.

Where excessive wear is observed due to rough tube surfaces, the use of abrasive cleaning balls is recommended to restore a smooth tube surface before returning to standard sponge cleaning balls.

Storage

We warrant that our cleaning balls are free from defects in materials and workmanship throughout their specified shelf life. This warranty does not cover normal wear during service.

To maximize storage life, cleaning balls should be stored:

• In a cool, dry place.
• Protected from direct sunlight.
• Away from excessive heat or freezing temperatures.

To prevent deformation, the balls should preferably remain in their original packaging.

As a general guideline, cartons should not be stacked more than two layers high during storage. If the balls are removed from their packaging, they should be stored loosely rather than under compression.

Note: Abrasive cleaning balls should be used with caution to avoid increasing the risk of corrosion, particularly in brackish water, seawater, or other cooling waters with high chloride concentrations.