When a medical supply customer urgently required uninterrupted softened water for sterilisation processes, Allmech was able to deliver a reliable duplex water softening solution within just two days, despite having no conventional duplex control valves in stock at the time. The team turned to an alternative already proven in practice by Runxin: a ceramic 3-way L-type ball valve configured to manage two softener vessels in a continuous-duty system.
Allmech is a leading South African manufacturer of boilers and supplier of water treatment equipment and chemicals and services customers across a wide variety of sectors. “We know that in healthcare-related environments, any interruption to water quality or supply can have immediate operational consequences,” says Anelia Hough, water treatment consultant at Allmech. “The customer required a production capacity of 4m³/h and continuous availability of softened water, with no tolerance for downtime during regeneration cycles.”
Drawing on recent exposure to the system in operation during a Runxin factory visit in China, Allmech’s managing director, Lionel Maasdorp, proposed using the Runxin ceramic 3-way valve to create a duplex configuration. The valve was installed on the outlet of the system and wired directly into the existing control valves. “The key was ensuring the correct electrical connections so the system could function as a true duplex softener,” explains Maasdorp. “Once that logic was in place, the solution was surprisingly simple.”
How the system works
The working process is cyclical. When the resin’s capacity to remove hardness from the supply water decreases to zero, a signal is sent to the 3-way ball valve to change direction. Water is immediately routed from the second softener vessel, which has already completed regeneration, while the first vessel begins its regeneration cycle. Once regeneration is complete, the first vessel returns to standby, and the valves continue alternating automatically. “The system was assembled, tested, and made available for collection within 48 hours. Performance has met expectations, delivering the required flow rate consistently and ensuring uninterrupted supply,” says Hough.
Benefits of the 3-way valve system
Beyond speed, the solution offers structural advantages over traditional duplex manifolds. Ceramic 3-way valves generally outperform conventional manifold arrangements in durability and reliability, particularly in abrasive or corrosive environments. While ceramic valves carry a higher upfront cost, their longer service life and reduced maintenance requirements can offset the expense of frequent manifold rebuilds over time. The configuration also reduces system complexity. Rather than relying on multiple valves and a complex manifold arrangement, a single ceramic valve controls flow between two vessels. This results in a more compact, mechanically straightforward installation.
While purpose-built duplex valves such as the Runxin F73 or F135 remain a cost-effective option for new installations where 24/7 soft water demand is known upfront, the 3-way valve approach opens new possibilities for existing sites. “This setup is particularly well suited to retrofit applications,” says Maasdorp. “Where a site previously operated with a single softener, but demand has increased, this configuration allows customers to upgrade to continuous operation without a full system replacement.”
Applications include healthcare facilities, industrial plants, food and beverage operations, and any environment where softened water must be available around the clock. For Allmech, the project reinforces the value of deep product knowledge and practical engineering judgement. “Sometimes the best solution isn’t a standard configuration,” Maasdorp says. “It’s about understanding what’s possible and applying it intelligently under real-world constraints.”
