Valves

Rotork has won a framework agreement for the supply of electric valve actuators to a UK water and wastewater services company, Thames Water. The exclusive agreement is set to run for a minimum of three years.

The majority of actuators supplied will be the IQ and IQT models. Thames Water was amongst the first of the UK 's water companies to use Rotork's IQ ‘non-intrusive' intelligent actuator technologies when first launched in 1993. Rotork's two-wire control capabilities, particularly regarding Profibus networks, were also important contributors to the Thames Water decision.

Dwyer Instruments has developed a new series of thermoplastic butterfly valves for chemical and wastewater applications.

The valves have a one-piece body design which incorporates fully supported flanged bolt holes to prevent stressing of the mating pipe flanges. They also feature a blowout-proof stainless steel stem and a unique, full body liner that has a V-notch retention design, which helps create a positive sealing of the liner to the valve body. There is also an integrally moulded face seal which provides positive sealing against the mating flange without the need for additional gaskets.

Grundfos has developed a multi-function valve with two diaphragms for Grundfos Alldos dosing pumps up to 60 l/h. The valve, which combines four functions - pressure loading, pressure relief, deaeration and drain - is directly mounted on the dosing valve. Grundfos says that the multi-function valve simplifies the handling of the pump and ensures process reliability.

If the system has not enough backpressure, the new multi-function valve can maintain the backpressure at the level which is necessary for the pump. In addition it protects the pressure-side dosing line system from an excessive pressure build-up. The pump can be deaerated and the pressure-side piping system can be drained via the multi-function valve.