Operation and test procedure Partial stroke testing

The Faith partial stroke test device consists of a custom made bracket and coupling drive bush and is mounted between the valve and actuator. No additional mounting parts between valve and actuator are required. The FAITH bracket is equipped with 2 blocking pins (standard above 1.000 NM) to centralize forces. This avoids damage to the valve and actuator seals during blocking of the stem at the test angle. FAITH’s design is simple and reliable. Being an easy to operate tool, it is used without any hesitation by operators as a standard device to perform a regular test.

A regular test can be viewed on a video on the FAITH partial stroke test device.

FAITH nmechanical partial stroke test device

Being an easy to operate tool, FAITH is used without any hesitation by operators as a standard device to perform a regular valve test

Manual operation

  • System can only be put into test mode after inserting a key
  • System is put into test mode by pulling the lever
  • One key for all systems or a unique key for every system
  • During testing, key is trapped
  • Key can only be removed when system is in normal operation
  • Once removed, key is stored in the control room
  • Custom Key Cabinet is available to store the unique keys in an orderly manner

Remote operation

  • Test is initiated and performed from control room
  • Same usability and functionality
  • Faster and easier test procedure
  • System put in test mode by actuated lever, which is operated from the control room

Partial stroke test device schematic view

Legend figure 1:

  1. Custom made bracket
  2. Linear key enables test mode
  3. Lever puts system in test mode
  4. 2 pins block travel of drive bush when in test mode
  5. Custom made coupling (drive bush between valve and actuator)
  6. Custom made hole patterns for directly coupling valve and actuator to FAITH device, without additional bracketing

Test procedure

During normal operation, the key is in the control room. The valve can be operated freely, so it can be opened or closed when necessary. When the valve needs to be tested, the following procedure must be followed:

Procedure for mechanical partial stroke test

Figure 2: Insert the linear key into the FAITH partial stroke test system to release the handle

Figure 3: Pull the handle to move the blocking pins into place for testing. The key is now trapped. The system is now ready for testing. The blocking pins will restrict the linear or rotating movement of the actuator to the requested percentage. After testing, when the actuator is back in its original position, pull the handle back and release the key to lock the handle and return key to the control room.

Download brochure of Netherlocks FAITH partial stroke test device