Local manufacturer and supplier of cable and pipe sealing systems Roxtec Africa has been awarded three contracts worth more than R2.4-million for its transit frame sealing systems by companies in the power generation, petrochemicals and mining industries.

Roxtec’s cable and pipe transit frames help to ensure operational reliability of industrial plants and reduce the impact of hazards induced by water pressure, fire, smoke, gas, temperature changes and seismic activity.

The sealing systems are contained in a multidiameter system, which consists of a steel frame, rubber sealing modules and a compression unit.

When the cables or pipes are installed in the frame, the sealing modules are lubricated and adjusted to the correct diameter.

The compression unit is installed when the frame has been filled with multidiameter modules and any unused modules in the frame allow for future changes to the system.

Similar to the multidiameter system is the Roxtec sealing system that has been installed at petrochemicals group Sasol Polymers’ ethylene purification Unit 5 plant, in Sasolburg, at a cost of R2-million, says Roxtec product manager Derek Colyn.

The order, which comprised cable seals for transformer cables, control cables and power cables, had been awarded to Roxtec by process-plant contractor Linde Process Plant in August 2011 and was completed in March.

Colyn says the final project handover is expected in the last quarter of this year.

Roxtec initially supplied a large stain- less-steel frame in September, which had formed part of the overall project construction phase.

“Thereafter, over a nine-month period, Roxtec supplied various stainless-steel G-frame modules, specifically for use in corrosive petrochemicals environments; blast load-resistant cable seals and frames; Roxtec Ex e-certified module seals; as well as compression wedges for electric equip- ment in hazardous areas, which were com- pleted in March, says Colyn.

Kolomela Mine Expansion Contract
Roxtec supplies the bulk of its industry- specific cable and pipe seals to iron-ore producer Kumba Iron Ore’s Kolomela mine on an ongoing basis, for use at the substations and control rooms, says Colyn.

The sealing systems manufacturer was recently contracted to supply cable transit frames, sealing modules, wedges and stayplates worth R370 000 to the new mine and the existing Sishen mine to prevent dust and rodent problems, which are common at iron-ore mines.

Roxtec systems were installed at numerous buildings inside the Kolomela process plant area, which included the 11 kV substation, the pump room, the radio-frequency room, the utility pumpstation, as well as the modular substations, says Colyn.

From the outset, Kumba requested that Roxtec cater for about 20% spare-cable capacity. Roxtec managed to install an additional 35% capacity, some of which has already been required for use, he says.

The Kolomela installation was completed in February.

Wonderboom Substation Contract
Colyn says Roxtec was awarded the Tshwane municipality Wonderboom substa- tion field control cable upgrade contract in July 2011, as well as an additional contract to replace transformer seals, which was awarded in September 2011.

The contracts have a combined value of R110 000.

“The cable sealing system order was placed by the main project contractor, high-voltage construction company Consolidated Power Projects, while electrical equipment manu- facturer Powertech Transformers specified the transformer seals as required by the Tshwane municipality,” notes Colyn.

He explains that the transformer contract is the result of a change in the Tshwane munici- pality’s engineers’ technique of terminating transformer cables.

The engineers requested that the same technique used on all the new 40 MVA transformers, which were manufactured by Powertech, in Pretoria, be used on all existing Tshwane municipality transformers.

“In the past, all 40 MVA transformers used the outdated technique of terminating transformer cables, called wiping gland,” explains Colyn.

Roxtec RS watertight seals replaced the traditional termination and, in doing so, dramatically reduced installation time.

This contract has resulted in Roxtec receiving additional orders from Powertech Transformers for other Tshwane sites, Colyn concludes.

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