Thermostatic radiator valve
What it is
Using a straight-shank rather than angled radiator vent with the TRV will allow the condensate to drain out of the radiator.
With two-pipe steam, the TRV can be placed at the radiator inlet where it is able to block steam entirely from entering the radiator when the TRV is closed.
In addition, there are two main types of TRVs operation: wax and bellows types (bellows types in turn can be either liquid or vapor filled), affecting response time.
Tune the building’s boiler so that is able to deliver dry steam at low pressure (no more than 2 psi) – if this is not the case, water hammer and excess operating pressures may damage the TRVs and/or limit their effectiveness.
A fluid-filled capsule inside the TRV operator expands as room temperature increases. As it expands it closes the valve, blocking entry of steam or hot water into the heat emitter. In the case of one-pipe steam, it blocks the release of air through the vent which prevents steam from entering the radiator (Figure 2).
Its parts
Related pages
- Glossary: Thermostatic radiator valve
Its entry, and the guide's pages that use it.
- Steam heat
How steam boilers and radiators work, air vents, banging and boiler rules
- Hot-water heat
How hot-water boilers and radiators work, bleeding, pressure and efficiency
Sources
- U.S. Department of Energy. Measure Guideline: Steam System Balancing and Tuning for Multifamily Residential Buildings.
- U.S. Department of Energy. Thermostatic.