When selecting a steam trap there are many points to consider to choose the appropriate trap. The below table is a good quick layout to help define which kind of steam trap would be more suitable to your application.
| Mechanical Trap | Thermodynamic Trap | Thermostatic Trap | ||
|---|---|---|---|---|
| Float | Bucket | Disc | Bellows | |
| Operating princlple | Difference in specific gravity between steam and condensate (up-and down movement due to buoyancy) | Difference in thermodynamic properties between steam and condensate | Difference in temperature between steam and condensate (Closed at steam temperature and opens at lower temperature) |
|
| Operating characteristics | Continuous | Intermittent | Intermittent | Continuous |
| Condensate accumulation | None | None | Possible | Possible |
| Steam loss amount | Negligible | Negligible | Small | Negligible |
| Discharge of air | Excellent | Fair | Excellent | Excellent |
| Water hammer proof | Fair | Excellent | Excellent | Poor |
| Back pressure tolerance | Excellent | Excellent | Poor(P2 must be 50% of P1 or less) | Fair |
| Response to load fluctuation | Immediate | Fair | Delayed | Delayed |
| Scale proof | Fair | Excellent | Poor | Fair |
| Size and weight | Large and heavy | Large and heavy | Small and light | Small and light |
| Installation posture | Limited* | Limited | Unlimited | Unlimited |
| Operation during failure (in many cases) | Closed | Open | Open | Closed |
| Application example | - Steam header, drain separator - Jacketed kettle· - Plate heat exchanger requring large condensate discharge and quick air-venting |
- Steam header - Steam main pipe - Main pipe end where noise of water hammer must be avoided |
- Steam main pipe end - ON-OFF controlled coil heater in boiling tank which has water hammer |
- Heat exchanger without water hammer - Air conditioning unit with limited installation space |
When selecting a steam trap there are many points to consider to choose the appropriate trap. The below table is a good quick layout to help define which kind of steam trap would be more suitable to your application.
| Mechanical Trap | Thermodynamic Trap | Thermostatic Trap | ||
|---|---|---|---|---|
| Float | Bucket | Disc | Bellows | |
| Operating princlple | Difference in specific gravity between steam and condensate (up-and down movement due to buoyancy) | Difference in thermodynamic properties between steam and condensate | Difference in temperature between steam and condensate (Closed at steam temperature and opens at lower temperature) |
|
| Operating characteristics | Continuous | Intermittent | Intermittent | Continuous |
| Condensate accumulation | None | None | Possible | Possible |
| Steam loss amount | Negligible | Negligible | Small | Negligible |
| Discharge of air | Excellent | Fair | Excellent | Excellent |
| Water hammer proof | Fair | Excellent | Excellent | Poor |
| Back pressure tolerance | Excellent | Excellent | Poor(P2 must be 50% of P1 or less) | Fair |
| Response to load fluctuation | Immediate | Fair | Delayed | Delayed |
| Scale proof | Fair | Excellent | Poor | Fair |
| Size and weight | Large and heavy | Large and heavy | Small and light | Small and light |
| Installation posture | Limited* | Limited | Unlimited | Unlimited |
| Operation during failure (in many cases) | Closed | Open | Open | Closed |
| Application example | - Steam header, drain separator - Jacketed kettle· - Plate heat exchanger requring large condensate discharge and quick air-venting |
- Steam header - Steam main pipe - Main pipe end where noise of water hammer must be avoided |
- Steam main pipe end - ON-OFF controlled coil heater in boiling tank which has water hammer |
- Heat exchanger without water hammer - Air conditioning unit with limited installation space |
