Do 2-pipe TRVs provide on/off control, or do they modulate?

sev

I'm trying to understand steam trap leakage, and would like to know if a 2-pipe TRV prevents steam trap leakage when the TRV is satisfied by closing the supply valve.



Thanks,

sev

Enreynolds

You have to understand

how the TRV works.  The TRV control contains a capsule ( or capilary tube in the case of a remote controller) full of a wax that expands when heated. As the room comes up to the setpoint temp, the wax gradually expands, pushing on and closing the the spring loaded valve.  So it does sort of modulate the steam entering the radiator.  Once the room temp exceeds the setpoint, the wax should have expanded to  the point that the valve is totally closed, not allowing any steam into the radiator until the room temp drops.  Thus you should not have any steam at the trap, at least at some point in the cycle, granting that the room heats up to the setpoint. 



What are you trying to accomplish?  A TRV is not a good solution to a leaking trap, and is more expensive than rebuilding the trap in most cases.  If you want to do away with trap maintenance, then you may be able to retrofit your system with orifices.

Let us know.

Eric

sev

reason for asking...

...estimating utility savings from fixing traps, based on hours steam is applied to trap.



To incentivize steam trap repairs, utility energy efficiency programs need reliable savings estimates = not simple, but something close, on average, can work as a starting point. If your area has utility efficiency programs, some have incentives for steam trap maintenance - better still if you can provide comprehensive system assessments.



BTW, anyone have an on-line source for steam trap sounds for both proper operation and various failure modes?



Thanks,

sev

nicholas bonham-carter

Noisy traps?

If the trap leaks, replace the innards. If the trap is noisy, then there may be an over-pressure issue as well.

Can you see what the pressure is on your system? The average for functionality is 1.5 psi. For economy, and comfort, the pressure should be no more than 6 ounces.--NBC

Enreynolds

Try this site

http://energyexperts.org/EnergySolutionsDatabase/ResourceDetail.aspx?id=555