steam boiler control

[jeremyr325]

I am looking for a way to control a steam boiler that has gravity return condensate. Do i reset the steam pressure with OSA? Need some ideals thank you for any help.

[klrogers]

No you can not reset steam pressure, if you need to do anything then do a duty cycle based on OSA temperature.

Kevin

[jeremyr325]

So there is really no controling a steam boiler beside a on/off input. Up for any suggestions

[Push It]

You should look into the Heat Timer controls.

[jeremyr325]

You should look into the Heat Timer controls.

could you explain?

[DaveCR]

http://www.heat-timer.com/En/Index.aspx

[Tecman1]

There is no way to reset steam as there is with water in a Hydronic System. In a one pipe system you would want to be certain the thermostatic air vents are working correctly at the radiators and that condensate is returning properly. If it is a two pipe system you would want to be certain the steam traps are not leaking by and the condensate is returning to the condensate receiver correctly. With steam it is more making certain the system is working according to design. The start stop time could work but could be a more complex strategy.

[bob_scheel]

I have a customer with an old 8 story bldg. that has poor insulation on the steam pipe risers and condensate return runs. They used to turn the steam on and off several times a day by hand because the radiant heat from the pipes in the walls would cause a lot of offices to be way to hot.

We put in a duty cycle timer that turns the steam on and off at 45-60 minute intervals. The length of time it remains on varys from a few minutes at 50 degrees outside air temp to the full 45-60 minutes at 20 degrees oat. (it never shuts off below 20)

This made a bad situation tolerable at a minimal cost and saved a lot of money because the hot offices no longer need to open their windows in the winter time.

Ideally the whole building should be updated, but old buildings don't generate a lot of rent.

[viceman]

heat timers work. i have been using them for decades.

[billcontrols]

On old steam systems sometimes a lower steam pressure setpoint will do wonders. I have had to change operating controls that operate at a PSI setpoint "Pressuretrol" for a "Vaporstat" that operates in ounces. With steam radiators the pressure is not what delivers the heat. The phase change of the steam is the heat source. Evidence of too high a steam pressure is overheating some rooms and condensate return problems. Of course there are other problems that produce those same symptoms (traps, vents, leaks, blockages). Honeywell L408J1009

Bill