VENTED ROLLER TYPE WEAR DETECTOR
The Exline Vented Roller Type Wear Detector may be used to monitor horizontal or vertical movement of reciprocating or rotating parts in applications where gas is used as control media.

The Detector has a replaceable stainless steel Vent Valve with a Viton™ seal rated at 375° F and a 1/4" n.p.t. male connection threaded to accept a pneumatic control system air line.

Principal application is to signal compressor rod drop. The Vented Roller Type Wear Detector may be installed directly below the compressor rod, where rod travel is horizontal, or on the thrust side where the rod travels vertically. If wear occurs on the piston, piston riders, crosshead, or cylinders, the rod contacts the Detector’s knurled wheel. Rod motion rotates the wheel, which in turn opens the Vent Valve connected to the pneumatic control system. A spring-loaded pin locks the rotated wheel into the “shutdown” position. The resulting pressure drop may be used to shut down the compressor automatically.

The Vented Roller Type Wear Detector can be used in applications where low ambient temperatures, certain synthetic lubricants, and incompatible rod coatings have ruled out the installation of heat-sensitive friction-type protective devices.

• Total Reliability
• No Maintenance
• No Calibration
• Temperature Independent
• Reusable
• Easy To Reset In Place
Order By Part Number
Vented Roller Type Wear Detector Assembly with Aluminum Wheel
320550
Assembly includes (1) ea. of the following items which can be ordered as spares:
 
Body, Aluminum
300550
  Wheel, Aluminum
300555
  Vent Valve
300101
  Locking Pin/ Spring Plunger
030301
  Vent Adapter Assembly: Jam nut, gasket, vent adapter, vent tube
030302
   
Vented Roller Type Wear Detector Assembly with Nylon Wheel*
320550-NLY
Assembly includes (1) ea. of the following items which can be ordered as spares:
  Body, Aluminum
300550
  Wheel, Nylon
300551
  Vent Valve
300101
  Locking Pin/ Spring Plunger
030301
  Vent Adapter Assembly
030302
* Not Suitable for engines that run over 350 hp
How to Order
The Vented Roller Type Wear Detector comes in one size only and can be used with rods of any diameter. Its aluminum
body is drilled and tapped so that the Vent Valve and spring-loaded plunger can be mounted on either side of the
device.
Details of Installation
The packing case nuts can be used as mounting points. Fabricate a metal bracket to support the Detector directly under, or on the thrust side of, the compressor rod. Drill and tap two holes in the bracket to attach the Detector.

To determine the appropriate clearance between Detector wheel and rod, consider the thickness of the piston rider band material, the location of the device in relation to the crosshead pin and the desired sensitivity. Insert a shim stock of the appropriate thickness between the rod and wheel, hold the device firmly against shim stock and bracket as the bolts are tightened. Remove the shim and pipe the Vent Valve to the control header. Tie into vent tube to vent to atmosphere or appropriate area.

No regular maintenance or calibration is required unless new compressor components are installed or packing is replaced. The Vent Valve can be replaced and the device reset to the marked “run” position without recalibration, but it is advisable to confirm the preset clearance after new parts are installed.
Setting Instructions
1. Determine which side will be accessible after installation.
2.  Install bleed valve, Part No. 300101 into body of RTWD.
3.  Install spring plunger / locking pin, Part No. 030301 into body of RTWD:
  a. Pull back plunger head and rotate the wheel until punch marks line up- this is the run position. Punch marks are located on each side of the wheel and on top of the RTWD body.
  b. Release the plunger head. The pin should seat down into a 1/8" stop hole in the face of the wheel.
4. Turn the wheel, making sure the plunger will release and hold in the shutdown position after dropping into the 1/8" hole. There will be a strong drag on the wheel as it is turned. It is important that the wheel is not locked into place too tightly so that it cannot move at all and not too loose so that it can move too easily.
5. Install complete Roller Type Wear Detector assembly, set proper clearance. Check for shut-down by simply turning the wheel.
  a. Suggested clearance for worn rings/ riders should be set at approximately .005" to .010".
  b. Suggested clearance for new rings/ riders should be set at approximately .010" to 0.15".