Device with at least two components , of which at least one component is at least partially exposed to an aqueous fluid, such as an HFC-Fluid, and can be fixed in a housing as an additional component, wherein - one component made from steel material, which is in contact both with the fluid and with the ambient air or nitrogen (Fig. 1), is chemically nickel-plated; - one component made from steel material, which is completely in contact with the fluid, is in particular installed statically and comprises gaps , particularly measuring < 0.5 mm, or seals between it and the adjacent component , is coated with zinc phosphate; - one component made from steel material, which is completely in contact with the fluid and is completely surrounded by the fluid in an operating state, is left uncoated; and - one component made from aluminium material is anodised, characterised in that at least one valve is installed as a component in a valve block as the additional component; in that the valve block is made from an aluminium material and is anodised on its outer side facing the environment; in that , on surfaces of the components having an electrical potential difference between a gap and an outer gap region and using sealing elements to seal the gap from the outer gap region, the following measures are proposed to avoid crevice corrosion for the respective component : - anodising aluminium material, - chemically nickel-plating steel material, the phosphorus content in the coating amounting to at least 10%, or - using stainless steel; in that , on surfaces of the components that do not have an electrical potential difference between a gap and an outer gap region, between which there is no fluid exchange, and with groove runs in the respective component , which seal two adjacent fluid chambers with the fluid against one another, and with at least one component which is arranged such that it is stationary or has only limited mobility, the following measures are proposed to avoid crevice corrosion for the respective valve component : - anodising aluminium material and - using steel material with a zinc phosphate coating; and in that , on surfaces of the components having an electrical potential difference between gap and outer gap region, when fluid is exchanged between the gap and the outer region and with groove runs in at least one component , which seal two adjacent fluid chambers against one another, and with at least one movable component , the following measures are proposed to avoid crevice corrosion for the respective component : - leaving the aluminium material uncoated and - leaving the steel material uncoated. - one component made from steel material, which is in contact both with the fluid and with the ambient air or nitrogen (Fig. 1), is chemically nickel-plated; - one component made from steel material, which is completely in contact with the fluid, is in particular installed statically and comprises gaps , particularly measuring < 0.5 mm, or seals between it and the adjacent component , is coated with zinc phosphate; - one component made from steel material, which is completely in contact with the fluid and is completely surrounded by the fluid in an operating state, is left uncoated; and - one component made from aluminium material is anodised, - anodising aluminium material, - chemically nickel-plating steel material, the phosphorus content in the coating amounting to at least 10%, or - using stainless steel; - anodising aluminium material and - using steel material with a zinc phosphate coating; and - leaving the aluminium material uncoated and - leaving the steel material uncoated. <EOS>