Anti-adhesive surface treatment
One of the most serious problems affecting the use of brass components coming into contact with water is the formation of limestone deposits into the ducts, especially near the hole intersections or section changes. This is particularly clear when the solenoid valves are used at high temperatures where limestone deposits form very quickly. Limestone deposits cause, in a more or less short period of time depending on water hardness, a progressive damage to the device operation resulting in a slow but relentless reduction of flow rate until it reaches the total absence when the solenoid valve internal movable parts (plungers) stop working. To reduce these problems, OLAB has strongly improved the quality of machined surfaces and obtained very low roughness levels, in the aim of reducing the limestone adhesive effect to a minimum. OLAB has also patented the application of a surface coating called TM1®, which increases the anti-adhesive characteristics. This coating, which is 15÷20 μm thick with a 350÷400 HV hardness, is also suitable for the food sector according to the fda american standards. When comparing the life of OT 58 solenoid valves with the TM1®‚ treated ones, it appears that the latter required maintenance (hole cleaning) after a number of operations three times that of the non-treated solenoid valves (*).
(*): this result has been obtained in tests with water hardness of 30° French degrees, water temperature between 85°C and 95°C, coil installed above the valve body (see installation section), cycle time around 10 seconds on / 25 seconds off.