A Delta Industrial knife gate valve from slurry equipment solutions provider Weir Minerals has been operating at a large international mining company for four years without any unscheduled maintenance, says Weir Minerals global product manager for valves John Abbott.

He explains that the company had been repairing the major valve on its tailings line every three months. “This was proving to be extremely inefficient and costly. They asked us to help solve this problem, which was costing them time and money.”

External leaks from valves during valve cycling are common problems for plant operators around the world.

The company stresses that hazardous material leaks can have disastrous consequences, contaminating the environment and endangering the lives of workers, resulting in major downtime for a company.

Delta Industrial knife gate valves can guarantee plant operators zero leakage in difficult process applications, emphasises Abbot. “This isolation is very important because it ensures safe and consistent plant operation, reduces downtime and provides lowest total ownership cost.”

Weir Minerals Delta Industrial guided shear gate valves are designed to repeatedly close and provide bidirectional zero-leakage isolation no matter what the process fluid may contain.

“Our knife gate valves guarantee no process [fluid] will [get] past the closed valve, [not] even abrasive slurry or when operating under high temperatures,” Abbott states.

This is a significant feature of Delta Industrial valves and one which offers customers numerous important benefits, providing some insight into why Weir Minerals acquired and continues to invest in Delta Industrial.

“Weir Minerals acquired Delta Industrial Valves in July 2015, increasing our market presence in the hard rock mining, oil sands, pulp and paper and power industries by expanding our portfolio of valve products,” Abbott states.

Weir Minerals is a global leader in the mining and oil sands markets and the acquisition of Delta Industrial Valves strengthens its comprehensive offering to customers through a range of high-performance knife gate valves for heavy-duty slurry applications and high-pressure environments.

Delta Industrial Valves was founded in 1987 and the company began designing and manufacturing high-quality knife gate valves in 1989. At the time, the company recognised the urgent market demand for a superior knife gate valve.

The company is an established valves industry leader and, with the backing of Weir Minerals, will continue to provide high-quality knife gate valves for its customers, notes Weir Minerals.

Not All Are Equal
Not all knife gate valves are the same – many allow for leakages which can leave plant operators exasperated, says Weir Minerals.

“[The Delta Industrial knife gate valve] construction provides a zero-leakage guarantee in external environments owing to its unique transverse seal design. Coupled with Delta Industrial’s long history in the design and production of valves, it consistently proves to be one of the best performing valves in these heavy-duty applications,” Abbott explains.

While many types of knife gate valves have been designed and manufactured since the 1950s, they have all had serious limitations. The Delta Industrial shear gate design, combined with its seating arrangement, ensures exceptional pipeline isolation and zero leakage into the atmosphere, resulting in performance customers can rely on every time the valve operates.

“Although there are at least five distinct types of knife gate valves marketed in the industry, we only produce absolute knife gate valves in our Delta Industrial range, capable of cutting, shearing and closing against solids, while still producing a tight shut-off,” he says.

The Delta Industrial knife gate valve has a design which is capable of offering the highest performance in the most severe applications where solids are in solution, suspension or both. This, says Weir Minerals, makes the valve the world’s premium isolation valve for scaling applications, where traditional valves are inoperable owing to cementation or precipitation of solids.

“What’s great about our Delta Industrial knife gate valves is that they even operate in clear solutions, an area where traditional knife gate valves are not appropriate,” Abbot adds.

The valve manufacturing process employs tight tolerances and minimum clearances to ensure reliable performance and the longevity of the highly engineered product, and customers benefit from consistent performance and lower maintenance.

“The Delta Industrial valve is designed to work in severe service applications, providing customers from a range of sectors [with] superior performance at high pressures,” Abbott states.

The valves are currently used in many industries, he says, highlighting that the valves are “heavily entrenched” in the oil sands process, “where performance is critical and leakage, both external and internal, cannot be tolerated”.

In terms of the future of Delta Industrial valves, Weir Minerals points out that it is currently working on complementing its range of ASME 600-rated valves.

There are also developments currently being tested which will provide enhanced performance in high-pressure applications. “We are all very excited about the product development and design innovations to help our customers and cannot wait to see these unfold,” Abbott concludes.