In many facilities across the US, failing steam traps go unmaintained, resulting in thousands of dollars in energy costs. When steam trap maintenance is neglected, traps begin to fail. This can cost your facility hundreds, even thousands of dollars in energy loss.
The steam trap is an integral part of any steam system, proper upkeep is a must. Below, we’ve compiled some tips to ensure you can detect failures before it’s too late and improve the efficiency of your steam system.
What are Steam Traps?
A steam trap is a mechanism that filters out condensate (i.e., condensed steam) and non-condensable gases. It does this without removing the live steam from the system.
Depending on the steam system, the quantity of condensate steam the trap can carry varies. The trap may discharge condensate as soon as the condensed steam forms, or it may hinder below the steam temperature.
Selecting the Right Steam Trap
Choosing the appropriate steam trap for your system is critical. Ensure that your selected trap can effectively perform its functions under varying conditions. Key considerations include:
- Operating pressures
- Heat load
- Condensate pressure
- Resistance to corrosion and dirt
Proper selection will enhance your system’s efficiency and reliability.
Types of Steam Traps
There are three significant types of steam traps that are classified by the International Standard ISO 6704:1982.
1. Thermostatic (operate by changes in fluid temperature)
A thermostatic trap responds to changes in temperature. Therefore, they distinguish very well between steam and cooler non-condensable gases. Its pressure greatly determines the temperature of saturated steam. The steam in the space gives up its heat and produces condensate at steam temperature. To prevent further heat loss, the condensate’s temperature will drop. The thermostatic trap will pass condensate when it’s at a lower temperature. As the steam travels to the trap, the temperature will increase, and the trap will close.
2. Mechanical (operated by changes in fluid density).
Mechanical traps tend to work by sensing the difference between steam and condensate. They include elements such as “ball float traps” and “inverted bucket traps.” In “ball float traps,” the ball will rise in the occurrence of condensate. Next, the valve will open and transfer the denser condensate. In the “inverted bucket trap,” the inverted bucket floats once steam reaches the trap. Once it reaches the trap, the steam rises, shutting the valve.
3. Thermodynamic (operated by changes in fluid dynamics).
Thermodynamic traps partly rely on the formation of the flash steam from the condensate. These traps can’t distinguish between steam and or other non-condensable gases. Steam traps associated with the thermodynamic trap include the following: disc, impulse, and labyrinth traps.
Testing Steam Traps
Like all mechanical devices, steam traps are subject to wear and tear. To keep them performing efficiently, they require maintenance to meet manufacturer specifications. Common issues you want to prevent include steam leakage or blocked condensate discharge (i.e., cold traps).
Identifying faulty traps within the system is important. Faulty traps can lead to continuous problems. If found, replace faulty traps immediately.
Diagnostic Procedures
Routinely monitoring your steam traps should be part of your steam trap maintenance plan. This will improve your process efficiencies as well as prevent additional damage to your piping. Some diagnosis procedures include:
- Listening devices
- Optical sight glasses
- Temperature monitoring
- Ultrasonic techniques
Note: These diagnostic procedures can become inaccurate as your system’s conditions change.
These methods can provide valuable insights into the condition of your steam traps. For more accurate testing, consider using a steam trap testing device equipped with a sensor that detects the physical state of the medium through conductivity. This device can facilitate local, remote, manual, or automatic monitoring, allowing for immediate detection of failures.
Routine Steam Trap Maintenance
With today’s energy costs and demand for production reliability, it’s imperative to execute a steam trap maintenance program. With a maintenance plan in place, teams can successfully identify defective steam valves, traps, strainer failures, and blowdown valve failures.
Common Causes of Steam Trap Failure
Two prevalent causes of steam trap failure include:
- Oversizing: Oversized traps may overwork, leading to premature failure.
- Dirt Buildup: Dirt and debris can cause plugging or prevent proper valve closure.
ndicators of Steam Trap Failure
Watch for these signs to assess steam trap performance:
- An abnormally warm boiler room
- Condensate receiving venting steam
- Premature failure of the condensate pump water seal
- Overheating or underheating in conditioned spaces
- Difficulty maintaining boiler operating pressure
- Challenges maintaining vacuum in return lines
- Water hammer in steam and condensate lines
- Steam buildup in condensate return lines
- Higher-than-normal energy bills
- Inlet and outlet lines showing similar temperatures
Steps for Testing Steam Traps
If you suspect your steam traps are failing, follow these steps to test them:
- Install a test valve downstream.
- Use sound equipment to listen to the action of the trap.
- Measure the temperature difference between the inlet and outlet of the trap.
Maintenance Procedures
Remember that maintenance procedures vary depending on the type of trap and its application. For instance, balanced pressure steam traps have elements designed for easy replacement, typically every three years.
Replacing Internal Parts
Replacing Internal Parts Consider changing out internal parts to repair steam traps, which can sometimes be more cost-effective than replacing the entire unit. For thermostatic traps, removal of the screwed-in seat is usually sufficient. In contrast, damaged thermodynamic traps may require more complicated repairs, including lapping the seating faces or replacing components.
Always consult with the manufacturer for proper maintenance techniques specific to your steam traps and site conditions.
Replacing The Traps
In most cases, it will be easier to replace traps than to repair them. You want to ensure you can change steam traps easily during routine maintenance. One solution to consider is flanged connections, even though a flanged trap is more expensive than the screwed trap.
Steam traps consist of a swivel connector that allows rapid, easy removal and replacement of any sealed trap. A swivel connector consists of a pipeline unit or connector that remains in the pipeline during maintenance of the trap. Each trap can be replaced by operating two bolts. The traps match to the same connector that’s providing the flexibility and rationalism of spares.
Steam is the primary heat source for many processing plants and large commercial buildings, which makes steam trap maintenance that much more important. If maintenance isn’t performed, then reliability issues are sure to follow. After all, proper maintenance can create impactful production and earnings benefits, as well as significant energy savings.
Need Help?
What are you waiting for? Reach out to the experts at Rasmussen Mechanical Services and ensure your facility is safe. Call us at 1-800-237-3141, email sales@rasmech.com, chat with a support agent, or contact us online.
