Rotork YTC Smart Valve Positioner YT3303

The YT-3303 exists for one reason above all others: on a sliding-stem valve it attaches to the left-hand yoke of the actuator, where the YT-3300 attaches to the right. If the valve’s handwheel, stem connector, tubing run or a neighbouring pipe leaves no room on the right-hand side — a constraint you meet constantly on retrofits and on tightly packed skids — the YT-3303 is the model that will physically fit without repiping the actuator.

The second distinguishing feature is pneumatic. The YT-3303 is the only member of the family fitted with a variable orifice rather than the plate-type orifices used elsewhere. Its flow to the actuator is set in the field with a flat screwdriver: turn the slot vertical for maximum flow, horizontal for minimum. That means a technician can damp out hunting on a small, fast actuator, or open the orifice up on a sluggish one, without removing the positioner or fitting a different orifice plate.

How the YT-3303 differs from the YT-3300, YT-3350 and YT-3301

The electronics are identical across the family — 420 mA DC, minimum 3.2 mA (3.8 mA with HART), 500 Ω maximum impedance, 0.140.7 MPa supply, IP66 and Type 4X (FM), HART rev. 7, SIL 2, LCD with four pushbuttons, auto-calibration, adjustable PID and partial stroke test. The differences that decide the order are these:

The other quiet difference is the linear lever range set. The YT-3303 uses four bands — 1040, 2070, 50100 and 100150 mm — where the YT-3300 uses three standard bands plus four adapter types. Match the band to the valve travel when ordering; the rotary levers (M6 or M8 × 34L or 63L, or NAMUR) are common with the rest of the family.

Specification

Hazardous-area protection is by intrinsic safety: ATEX, IECEx, KCs and NEPSI as Ex ia IIC T5/T6 Gb with Ex iaD IIIC T100 °C/T85 °C Db, or FM and CSA as Class I Division 1 & 2 Groups ABCD. The KCs certificate specific to this model is 14-KB2BO-0335X.

Typical application

Most YT-3303s we supply go onto retrofits. An existing globe or diaphragm valve is being upgraded from a pneumatic or analogue positioner to a smart one, the actuator was installed decades ago with its tubing, handwheel and stem connector arranged around a left-hand mounting, and moving all of that is neither quick nor cheap. Specifying the YT-3303 turns a two-day job into a two-hour one. This comes up constantly in sugar mills and older textile plants, where the valve population is long-lived and was assembled piecemeal.

The variable orifice earns its keep on small, fast actuators — the kind fitted to 1 in and 1½ in control valves on chemical dosing, boiler chemical injection and biogas scrubber duty — where a positioner sized for a large actuator will over-drive a small one and cause it to oscillate around setpoint. Being able to close the orifice down with a screwdriver during commissioning, rather than ordering a different orifice plate and coming back, is the practical benefit. Note the trade: if the valve also needs hard-wired limit switches, the YT-3303 cannot carry them and the YT-3300 or YT-3350 should be used instead.

View the product manual or the datasheet, or for more details visit the manufacturer’s website.