Create a custom Pressure Safety Valve / Pressure Relief Valve Test to run on a FieldLab

Create a custom Pressure Safety Valve / Pressure Relief Valve Test to run on a FieldLab

Create a new valve test and add it to a FieldLab Pressure Calibrator to test pressure safety valves (PSVs) and pressure relief valves (PRVs).
InfoThis feature requires:
  1. FieldLab Desktop App version 1.24.0 or later is installed on your PC. You can update from within the app if you already have it installed, or download the latest version for free.
  2. FieldLab Firmware version 1.123 or later installed on a FieldLab Pressure Calibrator. Learn how to update firmware.

Instructions for FieldLab Desktop app versions 2.0 and later

Idea
You don't enter the valve's Set Pressure in FieldLab Desktop when you create this test. The Set Pressure is entered directly on the FieldLab Pressure Calibrator during the test. Everything you configure in this test mode is calculated relative to that Set Pressure once it's entered on the FieldLab at the time of the test.

1. In FieldLab Desktop, select "Test Library"


2. Select the "New Test" button, and then select "PSV/PRV" from the dropdown menu.


3. Name the test mode
Enter a name in the Test Mode Name field.

4. Choose the method for Crack and Reseat detection


      Auto Detection of Crack and Reseat
      The FieldLab automatically detects, displays, and saves the crack and reseat pressures. Use this where the crack and reseat happen so quickly that it's difficult for a person to determine the exact crack pressure.

      Manual Marking of Crack and Reseat
      The person performing the test watches the valve and manually marks the crack and reseat events by pressing a button on the FieldLab. Use when testing liquid Pressure Safety Valves (PSVs) or proportional relief valves, which open gradually rather than popping, so manual marking captures the crack point more reliably.

5. Set the number of cracks per test
Note that the number you enter and save in this test will be the required number of tests to perform on the FieldLab Pressure Calibrator every time you perform a test.


6. (Optional) Set the threshold for high-speed logging

Begin high speed test: X% of Set point
While the test is running, the FieldLab starts logging at 10 readings per second. When live pressure reaches the threshold (75% by default), the logging interval speeds up to 200 readings per second to capture the exact Crack and Reseat points. The FieldLab can sustain this high speed for 30 seconds before its high-speed data buffer fills.
Because of that limit, set the threshold as high as your test allows. If you need to hold pressure near the Set Pressure for an extended period before forcing a Crack, a higher threshold keeps you in sustainable 10-reading-per-second logging during that dwell period and reserves the high-speed window for the final approach to the crack.


7. Set the acceptable crack range
The Acceptable crack range setting defines the pass/fail limits. A crack pressure that falls within the limits passes; a crack above the over-limit or below the under-limit fails. You can set the limits yourself (Any Value or Conditional) or apply a published standard with Use Preset.

Any Value
Applies a single pair of pass/fail limits to every crack test, regardless of the Set Pressure entered on the FieldLab. You'll enter the limits in Step 9.
Conditional
Applies two different pairs of pass/fail limits, divided by a Set Pressure breakpoint you specify. Useful when your acceptance criteria change with pressure (a fixed tolerance at lower set pressures and a percentage at higher ones). You'll enter the breakpoint and both limit pairs in Step 9.


Or apply a standard with Use Preset
Select Use Preset to choose one of three published valve-testing standards:
  1. ASME BPVC VIII.1 UG-134(d)(1)
  2. ASME BPVC VIII.1 UG-125(c)(3)
  3. ISO 4126-1
Selecting a preset automatically sets the acceptable crack range type and fills in the breakpoint and the over/under limits to match that standard. You can review the values entered in the threshold fields and the Summary panel before saving.


8. Set the default pressure unit
Use the Default Units dropdown to choose the pressure unit for the test. 

9. Set the pass/fail thresholds
How you enter the limits depends on the acceptable crack range type from Step 7. (If you applied a standard with Use Preset, these fields are already filled in for you. Review them and adjust if needed.)

If you selected "Any Value"
Enter the maximum by which the crack pressure may exceed the Set Pressure (the + field) and the maximum by which it may fall below the Set Pressure (the − field). Set each limit as either a fixed value in the default pressure unit or as a percentage of the Set Pressure, using the unit dropdown beside the + field. The same limits apply throughout the test, regardless of the Set Pressure.

If you selected "Conditional"
Define two pass/fail ranges separated by a Set Pressure breakpoint:
  1. In the If set pressure row, choose the boundary operator (is less than or equal to or is less than) and enter the breakpoint pressure.
  2. Under the first ...then the acceptable crack range is:, enter the + (over) and − (under) limits for set pressures on the lower side of the breakpoint.
  3. The second If set pressure is greater than... row covers the upper side of the breakpoint. Enter the + and − limits that apply there.
FieldLab Desktop automatically sets the second range's condition to complement the first, so the two ranges always cover the full pressure span with no gap or overlap: if you choose is less than or equal to X, the second range applies to set pressures greater than X; if you choose is less than X, the second range applies to set pressures greater than or equal to X. Each limit can be entered in the default pressure unit or as a percentage of the Set Pressure.

10. (Optional) Include a Seat Tightness Test
When you include a Seat Tightness Test, the FieldLab Pressure Calibrator records:
  1. That the test was performed
  2. The amount of pressure applied to the seal
  3. The duration of the pressure application
  4. Whether it passed or failed
The FieldLab Pressure Calibrator interface prompts you to determine PASS/FAIL status at the time of the test.


11. Save the new test mode
Select Save to save the test mode.



Instructions for FieldLab Desktop app versions 1.0 through 1.44.8

1. In the FieldLab Desktop app, select "Test Modes"



2. Select the "New" button, and then select "PSV/PRV" from the dropdown menu.

3. Name the test mode


4. Select Crack & Reseat Detection

Auto Detection of Crack and Reseat
When you select auto detection, the FieldLab will automatically detect, display, and save the crack & reseat pressures. Ideal for scenarios where the crack and reseat happen so quickly that it's difficult for a human to determine the exact crack pressure.

Manual Marking of Crack and Reseat
With this setting, the person performing the test watches the valve and manually marks the crack and reseat events with the press of a button on the FieldLab.
It is recommended that you select the manual setting when testing liquid Pressure Safety Valves (PSV) or proportional relief valves (PRV).
5. Select the number of crack tests you want to perform on the PSV/PRV. 

6. (Optional) Adjust the high-speed test threshold to avoid high-speed data buffer overrun.

Note: The Set Point is entered directly on the FieldLab Pressure Calibrator when you run the test. Everything you configure in this test mode:
  1. The high-speed threshold
  2. acceptable crack range
  3. seat tightness settings
...is calculated relative to that Set Point once it's entered on the device.


While the test is running, the FieldLab logs at 10 readings per second. When live pressure reaches the threshold you set here (75% by default), logging speeds at 200 readings per second to capture the exact Crack and Reseat points. The FieldLab can sustain this high speed for only about 30 seconds before its high-speed data buffer fills.
Because of that limit, set the threshold as high as your test allows. If you need to hold pressure at, say, 80–95% of Set Pressure for an extended period before forcing a Crack, a higher threshold keeps you in sustainable 10-reading-per-second logging during that dwell period and saves the high-speed window for the final approach to Crack.

7. Select acceptable crack range

Simple Crack Range
Simple Crack Range sets the pass/fail limits. Enter the maximum the crack pressure may go over the Set Point (or Set Pressure) and the maximum it may go under; set each as either a fixed value (psi) or a percentage of the Set Pressure. A crack that falls within both limits passes. A crack above the over limit or below the under limit fails. The same limits apply throughout the test, regardless of the Set Pressure entered on the FieldLab.
Conditional Crack Range
Similar to Simple Crack Range, Conditional Crack Range allows you define your own custom parameters, but with more options to handle if-then scenarios.

When you select any of the following for acceptable crack range:
  1. ASME BPVC VIII.1 UG-134(d)(1)
  2. ASME BPVC VIII.1 UG-125(c)(3)
  3. ISO 4126-1
...specified standards will be applied to the test as defined by The American Society of Mechanical Engineers (ASME), or the International Organization for Standardization (ISO).
8. (Optional) Include a seat tightness test

If you are including a Seat Tightness Test, enter your desired settings for Length of test and Static Pressure Setting. 

When you include a Seat Tightness Test, the FieldLab will enable you to record in your test data that the Seat Tightness Test was performed, the pressure that was applied to the seal, the length of time the pressure was applied, and whether it passed or failed. The FieldLab Gauge interface will prompt you for PASS/FAIL status at the time of the test.


9. (Optional) Select Custom Data Fields to be included with the test data

For more information on creating and adding custom data fields, see Add Custom Data Fields to your Data Sets.

10. Save the new test mode

Next Steps
Add the test to your FieldLab(s).
In order to use the test you created on a FieldLab to test a valve, you must add it to a FieldLab. See Add Test Modes to a FieldLab for instructions.
Use your FiedLab to perform a valve test.



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