AC-LVDT Linear Position Sensors PGHD Series Power Generation Steam Control Valves

For Use In
Interceptor Valves
Governor Valves
Throttle Valves
Bypass Valves
Stop Valves
PG Series
LVDT Linear Position Sensors
Specifically Designed and Engineered for Applications in Power Generating Steam Turbine Control Systems

Alliance Sensors PG series LVDT linear position sensors are designed and engineered specifically for steam turbine valve position control system applications in electric power plants. Many of the features incorporated in the design were actually requested by power generation controls engineers. PG sensor models include the PGHD Heavy Duty LVDT and the PGSD Super Duty LVDT.  Both PG versions are available on special order as mild radiation resistant for operation in BWR nuclear power plants.

The PG Series LVDT linear sensors are heavy duty, from the wire connection terminal block inside an IP-68 sealed heavy wall housing to the 3/8 inch outside diameter core rod in which the LVDT core is encased so that it can never vibrate loose or break off. A pair of double contact shaft seals for the core rod keep dirt and water out of the sensor’s bore. An in-line ball joint coupling on the core connecting rod to take up minor installation misalignment is optionally available, along with other installation hardware such as hold-down clamps, threaded core extension rods, swivel rod eye ends, and mounting flanges. Electrical connections utilize a screw-clamp terminal block for 24 to 14 AWG wires that feed through a 3/4 inch conduit hub outfitted with a 1/2 inch conduit adapter. User-installable connectors are available.

  • - Core is Enclosed in 3/8 Inch (9.5 mm) Diameter Rod...Cannot Vibrate Loose or Break Off
  • - Dual Redundant Double Contact Shaft Seals Keep Contaminants out of LVDT’s Bore
  • - Works in 3-Wire, 4-Wire, 5-Wire, 6-Wire, and Ratiometric (A-B)/(A+B) Systems
  • - Operates to 350°F (175 C) with Over-Temperature Indicator Built in
  • - Screw-Clamp Terminal Block Accepts 24 to 14 AWG Wires
  • - 2 Year Warranty...Twice the Industry Standard
Excitation Frequency: 3 kHz nominal
Excitation Voltage: 3 V ACrms nominal
Full Scale Output: 0.9 V ACrms output (nom.) from differentially connected (S1-S2) secondaries with 3 Vrms excitation; sum of secondaries output is constant over range for ratiometric (S1-S2)/(S1+S2) operation
Linearity Error: ≤±0.5% of FSO nominal, ±0.5% of FSO max
Operating Temperature: -40 to 175 C (-40 to 350 ̊F)
Temperature Coefficient: ≤±0.025% FSO/degree C
Shock: 1000 g, 11 msec
Vibration: 5-20 Hz, 0.5 inch p-p; 20-2000 Hz, 4.2 g p-p
Ordering Info Table



Operating Range

Coupler Type

Rod Coupler Size *







HD Heavy Duty

0203 2 to 3 inches

BJ Ball Joint

3S 10-32 UNF, 1/2 inch deep


SD Super Duty

0406 4 to 6 inches

RN Rigid Nut

4S 1/4-28 UNF, 1/2 inch deep



0609 6 to 9 inches


5S 5/16-24 UNF, 1/2 inch deep



0912 9 to 12 inches


6S 3/8-24 UNF, 1/2 inch deep



1215 12 to 15 inches


6L 3/8-24, 3/4 inch deep (default)





8M M8 x 1.25, 14 mm deep





10M M10 x 1.5, 14 mm deep





* No size callout gets 6L default

Configuration Table

Model Number

Linear Range

Body Length ‘A’




165.1 MM



10.25 INCHES

260.4 MM



13.25 INCHES

336.6 MM


12.00 INCHES

17.25 INCHES

438.2 MM


15.00 INCHES

21.25 INCHES

539.8 MM



Body Diameter ‘B’


1.05 INCHES [26.7 MM]


1.32 INCHES [33.5 MM]


If you are looking for CAD drawings of our PGHD sensor, simply call us at 856-727-0250 or use the online contact us form by clicking here.