Engineering News and Mining Weekly
Valves are critical components that should not be overlooked
Viewing valves as insignificant components and, consequently, failing to procure the most suitable solution for a robust application is a common occurrence that impacts negatively on the uptime of any minerals processing operation.
“During plant operations, companies often experience the regret of purchasing lower quality valves. This is where we emphasise the importance of considering the total cost of ownership (TCO). Starting with a premium product lowers TCO and eliminates buyer’s remorse down the line,” heavy-duty valves manufacturer FLSmidth regional product line manager for pumps, cyclones and valves Herman Britz tells Mining Weekly.
Through its latest iteration of the KREBS Technequip bidirectional knife gate valve, launched in 2021, FLSmidth has introduced significant technological advancements that deliver the highest-quality valve that will not leave end-users feeling caught off guard, says FLSmidth regional product line manager for pumps, cyclones and valves Diren Lalla.
“In the near future, this will be the only valve we sell as we phase out our legacy valves when they warrant replacing,” adds Britz.
The advancements included in the KREBS Technequip knife gate valves have seen demand increase in Southern Africa, where FLSmidth’s product has a proven record of operating in harsh, abrasive applications across various commodities and materials.
“The premium materials used to manufacture this valve range ensure that your valve will last longer, reducing TCO, when compared with various other valves in the market that have been manufactured using subpar materials,” says Lalla.
For example, the thickness of the elastomer sleeves used enables a KREBS Technequip knife gate valve to handle longer periods of actuation. These sleeves and gates are the only parts requiring replacement during on-site maintenance intervals as they are the only part in direct contact with the slurry, aiding the longevity of other components.
Persistent Pressure Performance Under
The open body style of the valve still offers excellent isolation at high pressures in abrasive slurry applications, says Lalla.
Britz adds that isolation is also aided through two full flanges on either side of the valve.
“You can use the valve in ‘deadend service’. Therefore, the valve can be closed and you can work on the rest of the pipeline without any chance of leakages at a higher operating pressure than that offered by opposition valves.”
Further, FLSmidth’s KREBS Technequip valves are also designed to withstand higher pressures through the inclusion of a thicker gate design compared with the company’s legacy valves.
Drops in pressure are also avoided through the inclusion of a full port flow design. The KREBS Technequip knife gate valve enables the gate to move completely clear of the slurry’s path when the valve is open.
“That means there's a reduced drop in pressure where the valve is installed on a pipeline and your parts last longer as well, because there's less turbulence,” explains Britz.
Similarly, when closing the knife gate valve, its push-through or self-cleaning feature ensures that the gate closes every time without fail. The underside of the valve is open and allows for slurry to be pushed clear of the gate’s path to create a proper seal. This also prevents the gate from bending, as traditional, closed-body valves are prone to do, when there is an obstruction, impacting on the integrity of the valve.
Cleaner Lubrication
Lalla highlights that the lubrication of the KREB Technequip valve is another notable feature.
“The lubrication of the gate has been improved to make it much easier for an on-site team to apply grease when needed into ports without having to worry about dust ingress or slurry escaping. The wiper blade has also been redesigned to change the way in which it is inserted to scrape away slurry as the gate is coming up, as part of the valve’s self-cleaning feature.”
The KREBS Technequip valves also include flush ports around the wiper blades to flush the cavity to prevent any build-up that might occur at the wiper blades.
Interchangeable Parts
When considering whether to upgrade their valve, end-users benefit from the KREBS Technequip knife gate valve’s interchangeable frames and actuators, which are either pneumatic, hand wheel, bevel gear, hydraulic, electric or chain wheel. Therefore, end-users do not need to change the frame of their valve to replace the actuation type, states Britz.
Being able to supply standardised, interchangeable parts, FLSmidth reduces the end-user’s spare parts stockholding requirements when considering demand planning.
Complementing the support provided by its field-service, aftermarket team, automated demand planning is also offered by FLSmidth through the digitisation of an end-user’s historical parts consumption. Thereby, orders are automatically placed on an end-user’s behalf with relevant parts departments.
With an installed base mostly in South Africa, the KREBS Technequip knife gate valve range can accommodate pressures up to 51 bar and ranges between 50 mm and 1.3 m in diameter to handle an array of demanding applications, concludes Britz.