SPAIN: Sanhua has announced that its RFKH range of thermostatic expansion valves are suitable for use with lower GWP R404A refrigerant alternatives R448A, R449A and R452.
The new RFKH series of thermostatic expansion valves with interchangeable orifice is seen as a natural evolution of Sanhua’s existing range of RFKA thermostatic valves. Like their predecessors, the RFKH valves also feature a brass body, copper connections and a stainless steel head. The main difference is the use of a stainless steel bulb and capillary tube instead of copper.
The increased thermal exchange obtainable with a copper bulb, combined with a reduction in the thickness of the bulb’s steel cylinder, has enabled Sanhua to maintain the valve’s reactivity. In addition, the use of stainless steel in the bulb and capillary tube also brings greater strength to the valve and reduces the risk of capillary tube damage in the event of accidental impacts or unusual vibrations.
RFKH series valves can be used for both cooling and air conditioning applications and are available for the main refrigerants currently on the market: R407C, R134a, R404A, R507. A different version for R22 is available for non-EU markets.
The RFKH05 series has been developed for use with R410A, something not normally easily attainable with interchangeable-orifice thermostatic valves. A specific series has also been introduced for R407A/R407F refrigerants, proposed as a low-GWP alternative to the widespread R404A.
The RFKH range also offers flexibility of choice in regard to types of fitting with a threaded inlet and outlet (SAE flare), a configuration mainly used by installers, and with metric or imperial welded fittings. In the latter case, accessories such as weld adapters allow the screw fitting to be replaced with a welded fitting on the valve inlet. The valve bodies, available with internal or external equalisation, allow for the insertion of orifices with an increasing pass-through section with eight different sizes to choose from. For example, with refrigerant R407C the capacity varies from 1.3kW to 22.1kW, whereas with R410A it varies from 1.3 kW to 26.8 kW.