In brief
A valve terminal combines several pneumatic valves on a common base plate with a central compressed air supply and grouped electrical control.
Contents
What is Valve terminal?
Instead of piping and wiring each valve individually, many valves are mounted side by side on a valve terminal. Supply pressure and exhaust run through common channels, and control is centralised. This saves space, assembly time and wiring and is widespread in packaging machines, assembly systems and process engineering.
The stations hold valves with different functions, for example 5/2-way valves with spring or pulse return, 5/3-way valves or two 3/2-way valves in one housing. The electrical connection is via a multi-pin plug or a fieldbus or Ethernet module; some terminals integrate input and output modules. Key parameters are pitch, number of valve stations, flow rate, pressure range, voltage, port sizes and degree of protection. Pressure zones allow different pressures on one terminal.
Failures usually affect individual valves, solenoid coils, seals between valve and base plate or the electronics. Contaminated or oily compressed air shortens service life. Because valve terminals are configured for specific projects, ordering an identical new unit is hardly possible without the complete code. For critical machines, individual valves and coils from the installed series are therefore often kept in stock as spares.
In practice: maintenance and procurement
The order designation of a valve terminal is often a long configuration code that defines the valve functions and modules for each station. To replace individual valves, their own type designation is usually sufficient; for the complete terminal, the full code from the nameplate should be available.
Synonyms and abbreviations: valve manifold · valve island · pneumatic valve terminal · manifold valve block
Frequently asked questions
What are the advantages of a valve terminal over individual valves?
A valve terminal combines compressed air supply, exhaust and electrical control. This reduces hoses, cables and assembly work, saves space in the control cabinet or on the machine and simplifies troubleshooting. Via a fieldbus or Ethernet connection, diagnostic data can also be reported to the controller.
Can individual valves on a valve terminal be replaced?
On most valve terminals, individual valves or solenoid coils can be replaced without removing the entire terminal. The compressed air must first be shut off and the system exhausted. It is important that the replacement valve corresponds exactly to the function and series; the seals to the base plate should be renewed at the same time.
What information is needed to replace a valve terminal?
Required is the complete order or configuration code from the nameplate, which defines the series, number of stations, valve functions, port sizes, electrical connection and, where applicable, pressure zones. Photos and the assignment of each station are also helpful. For fieldbus modules, the protocol and firmware version must be stated.
Why does a valve on the valve terminal not switch?
Causes may be a missing electrical signal, a defective solenoid coil, a dirty pilot stage, insufficient supply pressure or a jammed valve spool. The manual override shows whether the valve switches mechanically. LED indicators and diagnostic data help to distinguish electrical from pneumatic faults.