FONTERRA has selected the new VS18 ISO standard valve range from Norgren for its Kauri site in Whangarei, New Zealand. The facility manufactures dairy products including milk powders, cocoa blends and creams.
Fonterra Kauri wanted to upgrade the solenoid valves that control the opening and closing of process valves in the steam generation plant. The number of different brands of solenoid valves they had on site was causing difficulty when pneumatic replacement valves and parts were required.
Solenoid valves are used extensively to control cylinders in packaging machines, palletisers, conveyors and to operate process valves.
The VS18 valves Fonterra chose conform to the new International Standard (ISO) 15407-2. The standard determines the valve to manifold interface footprint and the wiring connection between the valve body and wire-way entry in the manifold base.
The standard specifies solenoid valve interchangeability for compact 18mm and 26mm width valves. These valves are typically ported 1/8 BSP or 1/4 BSP and are significantly more compact than the older ISO 5599-1 dimensional standard 46mm width valves.
ISO 15407-2 also introduces multipole technology into the standard, with all electrical connections from the valves wired through the manifold base. The wiring terminates through one electrical connection, typically be a 25 or 44-pin D connector.
ISO 15407-2 also enables fieldbus serial communication protocols such as DeviceNet, Asi and Profibus to be used in the valve island. Other valve brands can also be used at a later date.
One of the advantages of the Norgren V18 valves for Fonterra was that the valve island was supplied fully assembled and tested. The V18 valves had integral 8mm push-in fittings and a 25-pin D Connector. During installation all that was needed was the push-in connection for tubing.
The D Connector with wiring only required connecting to one end. With multipole technology no individual wiring of solenoid DIN plugs is required.
Although ISO valves are generally considered a five-port function for the control of cylinders, the Norgren VS ISO valves are available in twin three-port valves. This effectively allows two three-port valves in one valve body to be operated separately. In an eight-station valve island this can enable up to 16 different process valves to be operated at any one time.
Fonterra selected single shut off plates as accessories for the Norgren VS valves, mounted between each valve and the manifold base. Should any solenoid valve in the manifold need removal for maintenance or replacement that specific valve can be isolated with an isolating screw (90° turn) in the shut off plate.
All other valves can continue operating with uninterrupted air supply. This was important to Fonterra where the solenoid valves control numerous process valves in the steam generation plant.
The VS18 ISO solenoid valves can be easily removed from the manifold base by loosening four cap screws. When the valve is removed the electrical connection is also disconnected. This saves having personnel disconnect electrical DIN plugs. Should a valve need replacement downtime is minimal.
Norgren has developed several other options that easily integrate into the valve manifold system. Sandwich flow controls can be fitted enabling cylinder or process valve speeds to be easily adjusted at one safe, central point. This is helpful during commissioning.
Sandwich pressure regulators can also be integrated enabling multi-pressure systems for different cylinders. This is particularly useful in packaging machinery applications.
VS18 and VS26 valves are available in soft seal or glandless spool configurations. The glandless spool has no moving seals and is constructed of a hardened alloy spool that is Teflon coated. The glandless spool technology offers longer life and the valve can sit idle for long periods without startup problems.