Checklist
Steam Trap Survey Checklist
A comprehensive steam trap survey checklist — covering testing methods, documentation, and failure diagnosis for all trap types.
5 min readUpdated July 2026
Pre-Survey Preparation
- Obtain trap list: Get a list of all steam traps with tag numbers, types, and locations from the CMMS.
- Verify trap tags: Walk the plant and verify all traps are tagged. Tag any untagged traps.
- Prepare tools: Ultrasonic tester, infrared thermometer, contact pyrometer, and survey forms or tablet.
- Schedule survey: Conduct the survey while the steam system is at normal operating pressure and load.
For Each Trap
- Record tag number and location: Identify the trap by its tag number. Note the location and application (drip leg, heat exchanger, tracing).
- Record trap type: Identify the trap type — thermodynamic (TD), float and thermostatic (F&T), or thermostatic.
- Measure upstream temperature: Use a contact pyrometer on the pipe upstream of the trap. Compare to steam saturation temperature at the operating pressure.
- Measure downstream temperature: Measure on the pipe downstream of the trap. Compare to upstream — a significant drop is normal; no drop suggests failed open.
- Ultrasonic test: Place the ultrasonic probe on the trap body. Listen to the sound pattern and compare to the known pattern for the trap type.
- Visual test (if possible): If a test valve is fitted, crack it open and observe the discharge. Intermittent = normal for TD; continuous = possible failed open.
- Diagnose: Based on all tests, classify as: working, failed open (blowing steam), or failed closed (backing up condensate).
- Record results: Log: tag number, type, temperature readings, ultrasonic result, diagnosis, and any notes.
Diagnosis Guide
| Symptom | Likely diagnosis | Action |
|---|---|---|
| Upstream temp = saturation, downstream temp close to upstream, continuous high ultrasonic | Failed open — blowing steam | Schedule replacement |
| Upstream temp below saturation, no ultrasonic sound, no discharge | Failed closed — blocked or stuck | Schedule replacement or cleaning |
| Intermittent ultrasonic, temperature drop across trap | Working — normal operation | No action required |
| Continuous flow sound, steady temp drop, F&T trap | Working — normal for F&T under steady load | No action required |
Post-Survey
- Compile results: Create a survey report with all trap results, failure rate, and estimated steam loss from failed traps.
- Calculate steam loss: Estimate the steam loss from each failed-open trap (use the orifice size and pressure). Calculate the annual fuel cost.
- Prioritise repairs: Prioritise failed-open traps by steam loss cost. Schedule replacements.
- Schedule follow-up: Test replaced traps 2–4 weeks after installation to verify correct operation.
How CHI can help
Ask CHI about steam trap survey procedures and to help diagnose trap failures from your test results. The CHI assistant can help you create custom checklists for your specific equipment, explain each inspection point, and flag items that need attention based on your equipment's condition.