Alliance Sensors Group introduced the PG series of LVDTs for power plant systems integrators and electric power utilities in 2008. This product line was specifically designed to solve various problems and minimize inconveniences associated with then existing LVDT position sensors used to measure steam valve position in both fossil fuel and nuclear power plants, and serving other functions in these plants. The PG series design is based on many years of making power plant valve position sensors and discussing requirements with the I & C personnel actually servicing and maintaining these plants. The following bullet points highlight many unique features of ASG’s time-proven PGHD and PGSD LVDTs that for years have made them the de facto industry standard for steam valve position sensing.
- LVDT core is totally enclosed in a tubular core rod and absolutely cannot break off or fall out.
- 3/8 in. (9.5 mm) dia. SS core rod assembly offers 5/16-24 or M8 x 1.25 male coupling threads.
- Core rod rides in a bronze bushing with double shaft seals against contaminants at each end.
- PG LVDTs have a built-in core rod stop for quick and easy calibration with ASG S2A modules.
- Ball joint and rigid couplings available to attach 5/16-24 or 3/8-24 threaded core extension rods.
- A 7/8-14 male thread (protected by a nut) projects from sensor housing to support accessory hardware like flanges, clamps, stacking kits, etc. and fits through a 1/2-inch conduit knockout.
- External auxiliary shaft seal with 5 Teflon chevrons available that fits on 7/8-14 housing thread.
- High sensor sensitivity and output permits operation down to 50% or less of nominal full range.
- All PG series LVDTs are rated for continuous operation at 350 degrees F or 175 degrees C.
- Internal temperature indicating label shows if LVDT was exposed to temperature over its rating.
- Terminal block in connection box for all LVDT connections eliminates failure-prone connectors.
- Terminal block connection markings match those of older LVDTs that use military connectors.
- Terminal block has screw-down serrated clamps for connection of 24 AWG to 14 AWG wires.
- Captive screws and lanyard on connection box cover keep parts from falling off during hookup.
- Connection box accommodates either 1/2-inch or 3/4-inch male conduit threaded hardware such as cord grips, cable clamps, and fittings for liquid-tite flexible conduit, armored cable, etc.
- PGHD LVDT aluminum housing is 1.050 inches in diameter, the same as 3/4-inch rigid conduit.
- PGSD LVDT aluminum housing is 1.315 inches in diameter, the same as 1-inch rigid conduit.
- Housing sizes permit use of ubiquitous Stauff saddle-style aluminum or polyamide tube clamps.
- All PG series LVDTs can be connected up as inductive half-bridges for use with GE controls.
- Mounting hardware available having same mounting centers and center height as GE sensors.