The filters with indicator are classified as “Vessels” in the sense of Directive PED 2014/68/EU, Article 2, paragraph 2 and are subject of Article 4, paragraph 1, letter (a), of the same Directive. All the product range is suitable for use with fluids proper to Group 2, as defined in Article 13, paragraph 1, letter (b), of Directive PED 2014/68/EU with reference to the Regulation (EC) n. 1272/2008, according to safety classification A1 in Annex E of the standard EN 378-1: 2016. Examples of refrigerant fluids are:
– HFC R134a, R404A, R407C, R410A, R507;
– Blends HFC/HFO R448A, R449A, R450A, R452A, R513A.
The function of a filter indicator is to protect the system from moisture, acids and solid contaminants; this filter must be installed on the liquid line. The presence of moisture, immediately highlighted by the indicator combined, may be due to the formation of ice; in charging conditions and during normal operation of the system, the refrigerant must pass in the indicator in the completely liquid state. The presence of bubbles indicates the partial evaporation of the fluid along the liquid line.
All types of filters with indicator have bodies and heads made of steel UNI EN 10130 – DC04. The assembly of the two parts is done by MIG welding. In this type of filter, the dehydrating charge is composed of a single and compact block with 100% of molecular sieve core from 3Å. This cartridge it’s coupled to a particular felt type which allows an efficient mechanical filtration combined with a low resistance to the motion of the fluid to the benefit of the effectiveness of dehydration. The presence of the indicator after the filter guarantees instantly the real effectiveness of the filter. The indicator is characterized by an element sensitive to moisture, which changes colour from green to yellow in the presence of moisture in the system; Yellow indicates that is needed to change the filter drier. The product range, as well as versions with SAE Flare threaded nickel-plated steel, offer models with solder copper-plated steel.
To optimize the performance, the filter should be mounted with the longitudinal axis vertical and the arrow pointing down. The importance of the filters within the system is such that it is advisable to provide for scheduled maintenance in order to verify the efficiency and thus to ensure the proper functioning of the system.