RS / RSL / RSR (en)

Type RS Sponge Balls are available in a range of standard sizes from 15 to 45 mm diameter, in 1 mm steps. Each size is available in a standard medium grade of hardness. Non-standard sizes or hardness’s are available on request.

The composition of the balls is based on a natural rubber mixture containing inert filler material. 10-20% of the mixture is vulcanizing agents. The exact mixture has been chosen so as to give the optimum combination of physical properties, ball in life and cleaning effect. There is no health risk associated with the ball mixtures; all chemicals used are permitted for use in contact with foodstuffs.

The standard colour is red. Light ball colour is yellow.

Immediately prior to use the balls are watered by squeezing them under water in the ball vessel about to 3 to 4 times to expel air.

To ensure that all tubes are cleaned, the watered balls should have a specific gravity close to that of the cooling medium.

They have a sinking velocity of:
Standard ball - 8-12 cm/sec.
Light ball - 1-4 cm/sec.

The Type RS Sponge Ball has been specially chosen for service in power plants and similar applications. There are a number of chemical species, including oil and other hydrocarbons, which can have a detrimental effect on the performance of the balls if present in appreciable quantities; carbons, which can have a detrimental effect on the performance of the balls if present in appreciable quantities; these are not common in cooling water systems. In consequence, the balls are resistant to virtually all types of cooling water.

Generally speaking, all types of sponge ball remove soft deposits of the usually found in once through cooling systems, such as mud, silt, sand, slime etc. To some extent, they can limit scale formation in harder waters by removing hard crystalline scales (e.g. calcium carbonate) as nuclei. However, they are ineffective one scales have become established.

Within practical limits, the cleaning effect is not significantly affected by either ball oversize (i.e. difference between ball diameter and tube i. d.) or grade of hardness. However, the ball diameter should always exceed the internal diameter of the tube to be cleaned.

The maximum permissible oversize is dictated by the available pressure drop across the heat exchanger and the need to avoid balls sticking in the tubes.

Ball life is strongly dependent on the cleaning frequency and the surface condition of the tubes to be cleaned. It is typically about 6 weeks, but can be much longer depending on local conditions and frequency of cleaning. Scaled and corroded surfaces have a particularly detrimental effect on ball life. The use of abrasive balls to polish roughened surfaces should be considered in case of excessive ball wear.