The steam trap survey is a planned inspection of several traps, with meticulous cataloguing of the critical facts relevant to each – type and size, steam pressure at trap input, the temperature at inlet and exit, and working condition. If the plant or steam system is extensive, the survey does not have to cover all of the traps on the initial pass. In reality, it is best to inspect a large plant by segment, system, or process unit. The task can be completed more fully if this strategy is used.
steam trap survey disguised by fittings, other equipment, or insulation, for example, can be found. Moreover, each trap may be marked. Steam trap surveys are labelled to help in record keeping and reporting by identifying their position. As the surveyors travel down the system, the tags can be produced of aluminium, stainless steel, or plastic using hand-operated printing equipment.
Tagging can adhere to pretty regular code. For example, ‘T-1’ would be the tag for the first trap on a tracer line; ‘D-3’ would be the third drip trap in a pipe system. Other names include ‘P-‘ for process, ‘H-‘ for heating, and ‘MB-‘ for metre box. Alternatively, a separate coding system might be created to meet the needs of a particular plant. The trap survey will show several forms of steam losses, such as open tracing and defective valves.
However, its primary function is to test steam trap survey performance. There are three techniques for examining traps
1. Visual Inspection
2. Sound Inspection
3. Temperature Measures
None of the checking approaches gives a “one-size-fits-all” solution for all trap troubleshooting scenarios. The best results can be obtained by combining checking methods or utilising one system to cross-check signals offered by another. Therefore, always employ more than one approach.
1. By the Visual Method
Visual inspection of condensate discharge from the steam trap survey is the simplest and best approach to assess its functioning. There is no additional equipment required, but you should understand the distinction between flash condensate and live steam. Figure 4 shows the difference between condensate and steam. When heated condensate is ejected into the environment, flash condensate develops as vapour. The appearance of flash is normal and does not indicate waste steam or trap failure.
If the trap does not discharge to the atmosphere but rather into a closed condensate return system, a test valve should be fitted downstream of the steam trap survey. When inspecting trap performance, close the isolation valve to cut off the condensate return line and open the test valve to the atmosphere. If flash and condensate discharge to the environment while the trap cycles a few times, the trap will fail.
However, assume the steam accompanying the condensate is not flash, but rather live steam discharging hot and at high velocity (and, in the case of a disc trap, with a rapid chattering over 60 times per minute). The steam trap survey might therefore be assumed to have failed.
2. By the Sound Method
Steam trap survey may be examined without visual inspection of the condensate emitted by carefully listening to them work. When working with a closed condensate return system, this procedure is more convenient. An industrial stethoscope or a DIY listening device such as a two-foot length of 3/16″ steel rod in a filehandle, a piece of wood dowel, or a screwdriver are required. With practice, you may hear the trap’s operation with any handmade gadgets by placing one end of the tool against the trap bonnet and the other end to your ear.
3. Measurements of Temperature
A steam trap survey is simply an automated condensate valve with the only function of passing condensate and holding back steam. This definition implies the existence of liquid condensate water. Trap functioning may be monitored by taking temperature readings on the pipeline about 12 inches upstream and downstream of the trap. This approach requires a basic contact pyrometer for readings on the pipe’s surface and information on line pressure upstream and downstream of the trap. There is a steam temperature for each steam pressure.
Review Application Basics
A steam trap survey is simply an automated condensate valve with the only function of passing condensate and holding back steam. This definition implies the existence of liquid condensate water. Trap functioning may be monitored by taking temperature readings on the pipeline about 12 inches upstream and downstream of the trap. This approach requires a basic contact pyrometer for making readings on the pipe’s surface and information on line pressure upstream and downstream of the trap. There is a steam temperature for each steam pressure.
- Oversizing – this is most likely the most prevalent sort of misapplication. Said, the trap has too much capacity for the scenario. Instead, try a smaller capacity steam trap survey.
- Freeze-Proof Installation – thermo-static and thermodynamic (disc) traps can be fitted to allow self-drainage, making the installation freeze-proof in cold weather. The freeze-proof approach for installing a Yarway disc trap, for example, is in vertical pipes discharging down. If the trap must be positioned horizontally, the bonnet should be on the side. Read the written instructions that came with the steam trap survey. Use a vacuum breaker to ensure gravity flow.
- Flow Direction – Although this may seem simple, traps are occasionally built backwards, with the upstream or inlet side hooked into the downstream pipe. Again, look for the arrow or ‘inlet/outlet’ marks on the trap and properly put them in the line.
- Trap Location – Condensate discharge pipe should be attached to equipment at its lowest position to avoid condensate collection or pockets from blanketing the heating surfaces. To reduce the water hammer, angle the pipe toward the trap.
- Gravity Flow to Trap – A proper pitch of the input pipe to the trap helps condensate flow toward the trap, displacing steam that would otherwise induce trap steam binding.
- Short Drainage Legs – These reduce the likelihood of freezing up in cold weather.
- Trap Each Unit Individually – If you try to drain more than one piece of equipment with one trap, short-circuiting is highly possible owing to pressure drop discrepancies. The unit with the lowest pressure drop will blanket or short circuit the others, resulting in uneven and ineffective heating.
- Determine the size of each trap– Condensate loads differ from one piece of equipment to the next. As a result, you can’t expect one trap to operate equally effectively in all situations. Higher capacity traps are required for greater condensate loads.