Don’t let steam manage you. Check out this roadmap to success.
By Kelly Paffel, Swagelok Energy Advisors, Inc.
In light of today’s energy costs and demand for production reliability, it’s more important than ever to incorporate a proactive steam trap station management program in your overall steam system management program. Here are some “must-do” and “must-have” elements associated with this comprehensive approach.
A steam trap station failure rate must be below 3% annually. To achieve this type of reliability, root-cause-analysis methodologies must be part of your program. We simply can no longer accept failures of more than 3% with station components: The cost is too high. Today, plant operation mandates that a steam trap station should provide a reliable service life of at least six years.
Why “steam trap station management” instead of “steam trap management?” A trap is just one component in a proper steam trap station arrangement. Reviewing a trap by itself—instead of as part of an entire steam trap station—can hamper effective steam operations.
Poor steam trap station management is a major cause of energy-dollar losses and significantly increases emissions in today’s steam system operations. A successful steam trap station management program can identify defective steam valves and steam traps, as well as strainer and blowdown valve failures. Additionally, with this information, the amount of energy and emission impacts for each valve or trap failure can be calculated. Benefits of effective steam trap station management include:
- Reduced energy losses
- Increased system reliability
- Minimized failure rates (below 3% p/yr)
- Decreased combustion emissions
- Decreased production downtime
- Improved steam quality
Today, a steam trap station should have a reliable service life of at least six years.
A 16-step program for success
The return on investment (ROI) from a complete and integrated steam trap station management program typically takes less than 12 months. As you review the steps to success, keep in mind that Step #1—one of the most important items on your “must-do” list—is to ensure that all personnel understand their roles in this success. Now consider the remaining 15.
Step #2. Identify all components in a steam trap station.
- Isolation valves
- Blowdown valves
- Steam trap
- Test valve
- Check valve (in some applications)
Step #3. Build a steam trap station management team.
Be sure to include personnel from all levels of the organization on this team:
- Management (a program needs management commitment to provide resources)
- Energy person or department
- Maintenance management
- Maintenance personnel
- Utility department
- Plant engineering
- Corporate engineering
Step #4. Determine desired end results.
- Reduced energy usage
- Reduced emissions
- Increased reliability
- Increased production performance
- Improved safety
Step #5. Select a steam team leader.
The team leader has a number of responsibilities, including, but not limited to:
- Coordinating all aspects of the program
- Managing and coordinating efforts among team members
- Facilitating communication
- Arranging appropriate meetings
- Assuring proper documentation
- Leading benchmarking efforts
- Defining steam team work efforts
- Documenting project progress
Step #6. Determine specific items for the team to address.
Include timetables/schedules, where appropriate.
- Steam leakage detection and correction
- To be carried out frequently
- To be carried out every six months
- Enhance proficiency
- Gas leak detection and correction
- To be carried out frequently
- Enhance proficiency
- Steam safety valve
- Ensure data is captured in the database
- Ensure preventive maintenance (PM)
A trap is just one component in a proper steam trap station arrangement. Looking at the trap by itself, instead of as part of an entire station, can hamper effective steam operations.
Step #7. Develop a training roadmap for plant personnel on various aspects of the steam system and its operation.
Examples of topics include:
- Steam traps
- Root-cause analysis
- Testing methods
- Correct sizing
- Condensate-recovery methods
Step #8. Track the steam trap stations in a database.
Do you know where your steam trap stations are located? All such stations need to be designated with a unique identification code. Critical information should be recorded on each station for future reference and entered into a database system for proper analysis. Examples of the information to be recorded during a steam trap station survey include:
- A map of all steam trap station locations
- Picture of the steam trap station, if possible
- Steam trap station number
- GPS location numbers
- Maximum steam pressure
- Minimum steam pressure
- Connection size
- Type of isolation valve
- Steam trap information
- Model number
- Casting material
- Orifice size
- Operational condition
- Type of condensate-return system
Step #9. Benchmark steam trap station performance.
A steam trap station survey can be performed either by company personnel or outsourced to an experienced firm. The survey should cover all elements listed here (and more to meet plant requirements). The information must be gathered on each steam trap station. If plant staff conducts the audit, auditing personnel should be certified as Level I or Level II Steam Trap Examiners.
Step #10. Use proper tools to test steam traps.*
The typical tools used for testing steam traps include the following:
- Visual inspection… Observe the actual steam trap discharge by means of a block and test valve. Since the flash steam amount from a properly operating steam trap station can be confusing, experience is required to understand what is observed from the test-valve discharge. But a trap that’s leaking during the off cycle or is severely leaking or completely failed will be easily detected. Remember, though, that this testing method changes the operating conditions of the steam trap due to the elimination of backpressure in the condensate-return line, which can affect some steam trap designs.
- Temperature measurement… Sense upstream and down-stream temperatures with contact pyrometers or infrared detectors. This method will determine whether there is blockage (steam trap is cold), as well as provide an estimated operating pressure with a correlation of the temperature to steam pressure.
- Ultrasonic detection… Ultrasound technology offers a simple—and highly accurate—means of testing steam trap stations. During proper operation, steam traps emit a distinctive high-frequency sound that can be picked up with an ultrasonic device.
(*Important Note: All of these tools require training of the person assigned to do the task.)
Step #11. Conduct in-depth testing and evaluation of existing steam trap stations to establish benchmarks.
Add all components, including steam traps, isolation valves, letdown stations, etc., to a database. Steam profiling or a steam balance is typically added into the program to help users understand the dynamics of the steam and condensate system.
Step #12. Review the benchmark data.
Analyze results from Step #10, then set a roadmap for correction. Review data from the steam trap station study to identify unreliable components and deficient installations. The goal of the process is to obtain a 3% failure rate in the steam trap station population. The results of the analysis will provide necessary information on the steam trap stations that are leading to the highest energy losses, which, in turn, will help set the correction roadmap. All failed steam trap station components will be collected and factored into the root cause analysis.
Step #13. Perform a root-cause analysis (RCA).
RCA is a method of problem-solving aimed at identifying the root causes of problems or events that result in the failure of the steam trap station components. The practice of RCA is predicated on the belief that problems in the steam system are best solved by attempting to address, correct or eliminate root causes, as opposed to merely addressing the problem by changing out the component with the same or similar component. The result of the latter action is that the failure will occur again.
By directing corrective measures based on the RCA, failure recurrence can more likely be prevented. It is, however, recognized that complete prevention of the failure by one corrective action is not always possible. Conversely, several effective corrective measures (methods) may address the root cause of a problem. Thus, RCA is often considered an iterative process—and frequently viewed as a tool of continuous improvement. Still, RCA is one of the most powerful tools in a steam trap management program.
Step #14. Evaluate steam trap stations in a selected area.
Based on the RCA, you may want to re-evaluate steam trap station vendors—to determine which of them can best meet your plant’s requirements. The team leader should determine 6-10 steam trap stations for evaluation purposes. Select locations where it’s easy to monitor the stations’ performance. The following suggestions can help simplify the evaluation process:
- Ensure the use of Universal mount design steam traps (ease of changeout = 5 minutes or less).
- A test valve arrangement should be used to inspect the steam trap discharge (steam, condensate, flash, etc.) during the evaluation process.
- A video record of proper steam trap operation should be taken for evaluation, benchmarking and training purposes.
- Select the operational design of the steam traps.
- Set a standard for the operational design of the steam trap that will be used in the different applications found in your plant (i.e., mechanical, thermodynamic and thermostatic). If you need assistance, contact your vendor. Most plants need more than one operational steam trap design, but not more than two.
- Proper steam trap sizing is the most important factor in obtaining efficient steam trap operation. Even though the correct operating design of a steam trap was selected and the installation was correct, improper steam trap sizing will cause either condensate to back up in the system or excessive steam loss into the return system. Be sure to review the necessary considerations in sizing steam control valves, steam piping, expansion and heat transfer.
Take time to consider all the parameters and to evaluate the dynamics of the system while making the correct sizing and selection of the steam trap. Steam trap sizing is not just a selection based upon pipe size—it also involves sizing of the internal diameter of the steam trap discharge orifice. For low-pressure commercial heating systems, manufacturers have developed traps whose pipe size relates directly to the steam trap capacity (orifice size). For industrial steam traps, though, this is typically NOT the case.
A 2” steam trap can have the same capacity as a steam trap with ½” connections. Only following the determination of the condensate capacity, maximum orifice pressure rating, operating steam pressure, pressure differential, and steam trap model can the pipe size or connections be selected.
• Steam line drip leg, unit heater, tracer or other small condensate loads will use a thermostatic design steam trap.
• Process applications (heat exchanger, reboiler, reactor, etc.) will use a free float: float and thermostatic design steam trap.
- Select manufacturers for the evaluation process.
- The plant needs to evaluate the steam trap station components that will be used in the plant. The best practice is to implement a methodical selection process for steam trap station evaluation and selection of vendors. Even if the plant is using a specific manufacturer, there is a need to reevaluate. New steam traps will leak steam; the plant must select one or two manufacturers with the least amount of leakage.
Step #15. Update your established standards for steam trap station installation.
After the RCA, the plant may need to update its trap installation and connection standards to help reduce the steam trap station failure rate. A high percentage of such is due to an incorrect steam trap installation. (See sidebar for where to obtain standards.)
Step #16. Take all benchmark data (after the corrections) and continue the steam trap station program on a PM schedule.
Do not let the program stop. It MUST go on, based on the timeframes shown here:
It’s a safe bet that fuel costs for producing steam will only be going up from here on out. Now’s a good time to begin a proactive steam trap station program. These 16 steps to steam system success are a good place to start. They’ll help you be a true manager of the steam, instead of letting the steam manage you. MT
Kelly Paffel is technical manager for Swagelok Energy Advisors, Inc., (SEA) based in Solon, OH. Telephone (888) 615-3559. Email: email@example.com.
Steam Trap Assistance
Where Can You Get Steam Trap Standards?
The Swagelok Energy Advisors (SEA) Website has standard installation prints, which can be provided in AutoCAD format upon request. Standards allow plant personnel to better understand the operation of each steam trap station and proper installation techniques. This will help eliminate repair or replacement costs due to incorrect installation.
To obtain these standards and/or to learn more about SEA’s services, click here.
For more info, enter 263 at www.MT-freeinfo.com