// Catalogue

Pneumatic Logic Valves: AND, OR, NOT, and Memory Function Valves

Pneumatic logic valves make simple control decisions with compressed air alone, so a machine can sequence, interlock and count without electrics. TSA Hydraulics Engineering supplies them within the Pneumatic Valves family of our Valves range, as single function valves and complete logic modules.

Air logic has one edge over a PLC: you can trace it with your finger. Follow the tubes, check each valve with a gauge, and the fault shows itself. That makes it a favourite on hose down lines, simple presses and older machines still earning their keep. Tell us the function and port size, and we will match a genuine valve or an equivalent.

// Buying guide

The Basic Logic Functions

AND (two pressure valve): gives an output only when both inputs have pressure. It’s used for two condition interlocks.
OR: gives an output when either input has pressure. The shuttle valve does this job.
NOT: gives an output only while there is no input signal, which flips a signal around.
YES: repeats a weak signal as a strong one, boosting it for long tube runs.
Memory: remembers which of two signals came last and holds that output, even after the signal goes.

Combine these, and you can build sequences, counters and safety interlocks with no power at the machine.

Other Function Valves

Two-hand control units: the machine only cycles when both buttons are pressed within about half a second of each other.
Sequence valves: switch when a set pressure is reached, so the next step waits until clamping is complete.
Pressure sensing valves: send a signal when pressure rises above or falls below a setting.
Time delay valves: hold back a signal for a set time.

Where Air Logic Still Makes Sense

Wet, hose down and washdown areas.
Areas with flammable gas or dust, where electrics need costly certification.
Simple presses, clamps and assembly jigs.
Portable tools, and machines with no power supply nearby.
Older machines that run well and only need parts.

Fault Finding Air Logic

Start at the output that should move, and work back towards the inputs.
Use a small gauge or tee indicator to check each signal.
Look for kinked, cut or crushed tubes before blaming a valve.
Check the supply is clean and dry, because sticky logic valves are usually dirty ones.
Replace like with like, because a NOT valve and a YES valve can look the same.

Pneumatic Logic Valves Specifications to Check

Logic function
Port size or tube size
Mounting: inline, panel, DIN rail or sub-base
Operating and signal pressure range
Response time for fast circuits
Visual indicator, if needed

Why Buy From TSA Hydraulics Engineering

As a pneumatic logic valves supplier, we match the function, porting and mounting, so a replacement drops straight into the circuit. You get OEM or equivalent options, and help sourcing pneumatic logic valves replacement parts such as indicators, sub-bases and seals. We tell you upfront whether a part is genuine or an equivalent.

// FAQs