SAMSON Type 3434 Pneumatic Controller Module

Adjustment of proportional action coefficient Kp

The Kp regulating throttle (usually a needle valve with a scale) is located on the front or side of the module. Kp is defined as the ratio of the output change to the input change (reciprocal in the proportional band). The adjustment range of 1-20 means:

Kp=1: Low gain, proportional band of 100%, smooth control effect, good stability but large static error.

Kp=20: High gain, proportional band of 5%, strong control effect, fast response but may cause oscillation.

In actual adjustment, it is usually started from a lower Kp, gradually increasing until the system exhibits equal amplitude oscillation, and then returning to 50%~70% of the critical value. For pneumatic controllers, adjusting Kp will change the sensitivity of the baffle nozzle mechanism.

Relationship with other controller modules

Type 3434 is just a sub series of the Type 3430 controller series. According to the data manual, there are more controller modules to choose from:

P controller (other models): may have different working point settings or a wider range of proportional bands.

PD controller: Proportional derivative control, suitable for large lag objects such as temperature control.

PID controller: Proportional integral derivative control, suitable for objects with complex dynamic characteristics.

Special task modules: such as ratio control, cascade control, selection control, etc.

The specific specifications and ordering information of these modules need to be found in data sheet T 7040 EN. The Type 3434 series is positioned as a low-cost, basic module, suitable for applications that do not require high control functionality but require high reliability.

Key points for installation and maintenance

1. Installation steps

Confirm that the gas supply pressure of the controller station (Type 3430) has been adjusted to 1.4 bar.

Align the plug of the Type 3434 module with the self sealing connector and gently push it into place.

Tighten the fastening screws (recommended torque of 0.3~0.5 N · m to avoid damaging the plastic shell).

Connect the gas supply and check for leaks. You can apply soapy water to the connection.

2. Debugging

Set the Kp throttle to the initial value (e.g. 5).

For the PI module (3434-2), it is also necessary to set the integration time (if adjustable).

Input analog measurement signals (such as using precision pressure reducing valves to provide 0.2, 0.6, 1.0 bar) and measure whether the output corresponds to the expected value.

After entering the closed-loop, adjust Kp according to the system response.

3. Maintenance

Regularly check the gas supply filter to ensure that the gas source is clean, free of oil and water.

Verify the input-output characteristics every 6 months. If the deviation exceeds 1% of the full range, clean the throttle or replace the module.

If the fastening screw slips, thread locking adhesive (low strength) can be used as an aid.

Troubleshooting Guide

Possible causes and solutions for the fault phenomenon

No output. Insufficient or interrupted gas supply pressure. Check the gas source and adjust it to 1.4 bar

Output always at maximum or minimum baffle nozzle blockage or damage Clean or replace module

Output fluctuation Kp is too large or supply pressure fluctuation decreases Kp, stabilize the gas source

Static error cannot be eliminated (PI type). If the integration time is set too long or the integration gas volume leaks, reduce the integration time and check the internal seal

After replacing the module, the self sealing connector of the controller station still does not work properly. Troubleshooting connector

Selection guide and ordering information

Select the correct model based on control requirements:

Only requiring proportional control, allowing for static deviation, cost sensitive: choose Type 3434-1

Need to eliminate static error, frequent load changes: choose Type 3434-2

Differential action required: Refer to T 7040 EN and select PD or PID module

Special algorithms (such as interval and ratio): select the corresponding special module

Order Text Format: Controller Module Type 3434-... Output 0.2 to 1 bar or 3 to 15 psi (specify output signal range, choose one of the two). For example, "Controller Module Type 3434-2, output 0.2 to 1 bar".

Comparative advantages with electronic controllers

Although DCS and PLC dominate in large factories, pneumatic controller modules are still irreplaceable in certain scenarios:

Intrinsic safety: No explosion-proof enclosure required, can be directly installed in hazardous areas (Zone 0/1).

Anti electromagnetic interference: not affected by lightning strikes, radio, and frequency converters.

Simple and reliable: without electronic components, the lifespan can reach several decades.

Low cost maintenance: On site personnel can clean the throttle and replace the diaphragm by themselves.

The Type 3434 module is an ideal choice for renovating old factories or building small pneumatic control systems based on these advantages.

Compatibility and Alternative Information

The Type 3434 module is fully compatible with the Type 3430 controller station. If the original system uses pneumatic controllers from other brands (such as Foxboro, Fisher, Moore, etc.), it is usually not directly interchangeable because the pneumatic connection size and signal range may be different. But if the entire controller station is replaced with Type 3430, the Type 3434 module can be used. For scenarios that require upgrading to higher performance, solutions with I/P converters or intelligent locators can be chosen, but the cost will significantly increase.