GIANT GLOBE-PATTERN VALVE FOR TSHWANE

Dynamic Fluid Control has announced delivery of its first order for the newly extended Cla-Val range of large-diameter Tytan globe-pattern control valves.

The 800mm, 40bar burst-control giant is the first of its particular size and configuration to be installed worldwide.

Customer is the City of Tshwane.

The new, higher volume Tytan globe-pattern valves are now available with nominal diameters from 700mm to 1200mm, and meet a need to be able to use this type of valve to control water flow in very large diameter water pipelines.

Previously available only in sizes up to 600mm, Cla-Val’s globe-pattern design is preferred by many water engineers to the larger but less efficient ball valves, ring-needle valves and sleeve valves.

These engineers continued to use the Cla-Val product as a control valve for very large diameter pipelines, which they divided into control pipes of smaller, manageable diameter in order to be able to incorporate the globe-pattern model.

City of Tshwane’s 800mm, 40bar Tytan valve will monitor and control the flow of one of Gauteng’s main gravity-feed water pipelines where it passes over a band of dolomite adjacent to the R21 highway.

The valve provides a solution to the planning dilemma of needing to route the pipe over the dolomite for reasons of economy, but having to run the risk of sink-holes that could break the pipe.

Cla-Val’s 800mm Tytan has allowed City engineers to achieve the required economy of construction while simultaneously eliminating any possibility of water loss and flooding.

The valve functions on the principle that any break in the pipe will cause an increase in water flow and a consequent decrease in pressure, with the valve responding by closing in stages according to manually set pressure parameters.

Manual re-setting ensures that engineers monitor the flow conditions for maximum response accuracy.

The valve has built-in surge protection.

Cla-Val’s Tytan valves are hydraulically operated and diaphragm actuated.

Comprising three major components – body, diaphragm assembly and cover – the diaphragm assembly is the only moving part, guided top and bottom by a precision-machined stem.

The disc retainer and rubber disc form a drip-tight seal with the renewable seat when pressure is applied above the diaphragm within the cover chamber.

When pressure is relieved, the pressure inlet opens the valve.

All Tytan valves are pressure balanced, and fitted with modulating controls that allow them to automatically compensate for pressure changes.

Dynamic Fluid Control has manufactured Cla-Val globe-pattern control valves under licence at its Benoni works since the late 1970s, in diameters from 50mm to 300mm.