The Rotork YT3100LSN5211S is a configuration of the Rotork YTC YT-3100 compact smart valve positioner, designed for precise control of pneumatically actuated control valves where stable, repeatable travel is critical to process quality. In a modern plant, the control system may calculate a perfect output signal, but real valves still suffer from friction, packing wear, fluctuating instrument air pressure, vibration, and temperature changes. A smart positioner exists to bridge the gap between a theoretical command and the messy physics of actual valve movement.
The YT-3100 platform is positioned as a reliable and precise smart positioner for both linear and quarter-turn rotary actuators, and it is available in both single-acting and double-acting layouts. In this specific model, the “LSN…” portion points to a Linear + Single-acting + Safe-area build, which is a common selection for globe valves and diaphragm actuators in non-hazardous installations that still demand dependable control performance.
Unlike older electro-pneumatic positioners that are often tuned by trial and error, the YT-3100 family is designed around field usability: a clear menu structure, predictable setup steps, and diagnostics that help reduce commissioning time and shorten troubleshooting loops. The datasheet highlights a menu with four push buttons, visual self-diagnostics rated to NE107, the availability of 4–20 mA position feedback, and a non-contact sensor concept aimed at high-frequency valves and longer service life.
Model Code Meaning (Why “YT3100LSN5211S” is more than a label)
Rotork’s YT-3100 datasheet includes a product code legend showing how the model string maps to functional configuration choices. The code structure is shown in the datasheet as:
YT-3100 – Motion type – Acting type – Explosion protection – Lever type – Conduit & air connection – Gauges block – Options – Operating temp. For YT3100LSN5211S, the mapping is:
| Code Segment | Meaning (per YT-3100 legend) | What it means in the field |
|---|---|---|
| YT-3100 | Aluminium housing with polycarbonate cover | Compact industrial enclosure format |
| L | Linear motion type | Intended for linear-stroke valves/actuators |
| S | Single-acting | Typically used with spring-return actuators for fail-safe behavior |
| N | Safe area | Non-hazardous installation classification in the legend |
| 5 | Lever type position (see note below) | Needs confirmation vs datasheet lever options |
| 2 | G 1/2 conduit + 1/4 NPT air connection | Common cabinet and pneumatic plumbing standard |
| 1 | Gauges block included | Local pressure indication for faster checks |
| 1 | PTM 4–20 mA feedback option | Position transmitter output back to PLC/DCS |
| S | -30 to +85 °C operating range | Wide ambient range for industrial sites |
Important accuracy note (no sugar-coating):
The YT-3100 legend lists linear lever types as 0, 1, or 2 (10–40 mm, 20–100 mm, 90–150 mm), while “5 = NAMUR” is shown under the rotary lever type section. That means “L…N…5…” is not a clean match to the datasheet’s linear lever coding. In practice, this usually indicates one of three situations:
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The model is written with a distributor shorthand that reuses a digit differently,
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The motion type or lever digit was mistyped (common in long strings), or
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The unit is intended to be paired with a specific mounting kit that effectively “forces” a nonstandard code representation.
Everything else in the string (L, S, N, conduit/air, gauge block, PTM feedback, temperature) aligns directly with the published legend.
What Single-Acting Linear Control Looks Like in Real Operations
A single-acting positioner is typically selected when the actuator has a spring return and the process requires a defined fail position (fail-open or fail-close depending on valve/actuator orientation and safety philosophy). In these cases, the positioner modulates air to move the valve against the spring and lets the spring provide the return force when air is reduced. This can simplify pneumatic plumbing and often makes safety behavior more predictable in utility service, water treatment, and general process lines.
A linear positioner configuration is commonly used on globe valves, angle valves, and diaphragm actuators—anywhere valve travel is a straight stroke rather than a quarter turn. The YT-3100 datasheet specifies a linear stroke capability of 10 to 150 mm, which covers a broad range of typical control valve strokes in industrial service.
Key Platform Features (YT-3100 Family Capabilities)
| Feature | Practical value |
|---|---|
| Compact smart positioner for linear and rotary actuators | Supports standardization across mixed valve populations |
| Single- and double-acting availability | Matches spring-return or double-acting actuator architectures |
| Gauge manifold / gauge block option | Faster air-side checks and simpler field verification |
| Four-button menu navigation | Straightforward commissioning without extra tools in many cases |
| NE107-rated visual self diagnostics | Clearer troubleshooting signals aligned to common maintenance practice |
| 4–20 mA position feedback option (PTM) | Valve travel monitoring, trending, proof-of-movement logic |
| Non-contact sensor concept | Intended for high-frequency valves and longer lifetime |
Core Specifications (From the YT-3100 Datasheet)
The table below summarizes the main published specifications relevant to configuring and deploying the YT-3100 family and, by extension, the YT3100LSN5211S configuration.
| Item | Specification |
|---|---|
| Input signal | 4 to 20 mA DC |
| Supply pressure | 0.14 to 0.7 MPa (1.4 to 7 bar / 20 to 102 psi) |
| Stroke range (linear) | 10 to 150 mm |
| Stroke range (rotary, reference) | 55 to 110° |
| Impedance | Max. 500 Ω @ 20 mA DC |
| Air connection | Rc 1/4, 1/4 NPT (depends on option) |
| Gauge connection | Rc 1/8, 1/8 NPT |
| Conduit | G 1/2 |
| Operating temperature | -30 to +85 °C (-22 to +185 °F) |
| Linearity | ±0.5% F.S. |
| Hysteresis | ±0.5% F.S. |
| Sensitivity | ±0.2% F.S. |
| Repeatability | ±0.3% F.S. |
| Air consumption | Below 2 LPM (at 0.14 MPa supply) |
| Flow capacity | 70 LPM (at 0.14 MPa supply) |
| Output characteristics | Linear, EQ%, quick open, user set |
| Ingress protection | IP66 |
| Weight | 1.7 kg (3.7 lb) |
Where YT3100LSN5211S Typically Fits
| Application area | Why this configuration is used |
|---|---|
| Globe valve control in utilities and general process lines | Linear stroke control with stable positioning behavior |
| Diaphragm actuators with spring return | Single-acting positioner pairs naturally with fail-safe actuator design |
| Non-hazardous plant areas | “N = Safe area” classification in the product code legend |
| Plants that want valve travel monitoring | PTM option provides 4–20 mA feedback for monitoring and analytics |
Selection Checklist (to avoid ordering mistakes)
| Check item | What to verify before purchase |
|---|---|
| Actuator motion and stroke | Confirm linear actuator and stroke within 10–150 mm range |
| Acting type | Confirm single-acting pneumatic design and fail position requirement |
| Area classification | Confirm safe-area installation (non-hazardous) |
| Pneumatic and conduit standards | Confirm 1/4 NPT air and G 1/2 conduit match site standards |
| Gauge block requirement | Decide whether local gauges are needed (this code indicates included) |
| Feedback requirement | Confirm PTM 4–20 mA feedback is desired (this code indicates included) |
| Lever digit mismatch | Because “5” is not listed under linear lever types, confirm with supplier documentation or photos of nameplate/mounting kit |
Summary
The Rotork YT3100LSN5211S represents a practical “workhorse” configuration of the YT-3100 family aimed at linear, single-acting, safe-area valve control—often chosen for spring-return actuators and globe/diaphragm valve applications where stable travel control and maintainability matter. The YT-3100 platform emphasizes compact design, clear field setup, NE107-aligned diagnostics, and optional 4–20 mA position feedback for monitoring and control verification.
