The IP system of ingress protection classification is designed to indicate the degree of protection against ingress of solids, liquids and mechanical impacts into enclosures in accordance with BS5490: 1977, IEC529:1976.

It should be noted that the system of quantifying degrees of protection does not relate to protection against corrosion or rust.

The level of protection is indicated by the letters IP followed by a 2 of 3 digit number.

The first digit relates to protection against solid objects, the second digit relates to protection against liquids and the third digit (often omitted) relates to protection against mechanical impacts.

Example: IP65 protected solenoid valve the coil would 6 Dust Tight and 5 Protected against water jets from any direction. When used in combination with a DIN43650 electrical connector, the classification of the connector must be equal too or better than the coil IP rating MUST BE fitted correctly with the connector and gasket and the correct size of cable to suit the cable gland, i.e. connectors with PG8 will clamp effectively against a cable diameter 6mm to 8mm and PG11 will clamp effectively against cable diameter 8mm to 10mm or PG6 5mm to 6 mm cable.

Important Note: Fitting an under size cable will mean the cable is not securely clamped and is an electrical hazard but also very vulnerable to water and dust ingress thus totally invalidating any ingress protection.

Helpful hint: when wiring into a connector it is recommended that the cable drops down away from the connector to avoid puddling or water ingress over time.

IP Ingress Protection Explained

Most solenoid valves for safe area use (non hazardous area) are IP65 as standard offering good ingress protection for dust and moisture (find IP65 solenoid valves here), however there are always exceptions such as IP54 which are commonly used in the USA, Canada and Far East. 

In rare instances such as low voltage applications for appliances and water dispensing equipment the solenoid valves are typically enclosed within a dry dust free cabinet and ingress protection is required and faston tags can be used. (find solenoid valves with faston tags)

For hazardous area use where there are or could be potentially explosive gases, fluids or dusts in the atmosphere then an ATEX solenoid coils must be used. These fall into different categories but basically there are 3 types: (find ATEX solenoid valves here)

ATEX Protection by encapsulation ll 2 G Ex mb ll T4 Gb and ll 2 D Ex tb IIIC T130°C Db IP65 

ATEX Protection by enclosure, EEx d IIC T flameproof solenoid coil

ATEX protection by intrinsic safety,  II 2 G Ex ia IIB/IIC T4 or T6.

IP65 valves out doors.

Caution: Typically the IP rating relates to the DIN connector and the solenoid coil when correctly assembled and installed with the correct size cable / clamp. However water ingress can still occur between the solenoid coil and the solenoid tube.  

IP65 rate means that items can stay outdoor because can face some low pressure jets of water and moisture for a certain period of time. Indeed IP65 test is not carried on for infinitive time. Third party labs, according to what norms say, carry on the test for some minutes.  

Hence, the definition of IP65 itself let user think about a shelter for prolonging life towards infinitive outdoor time.

We must remind that materials in general get aged more quickly outdoor than indoor because atmospheric agents.