When visiting a steam boiler room, I like to note the steam pressure settings on the pressure controls. Published: February 26, 2019 - by Ray Wohlfarth. Please click here to continue without javascript.. Top three reasons to pair PEXa with cold expansion compression-sleeve fittings, Modern Hydronic Heating and Cooling For Residential and Light Commercial Buildings, 4th Edition, Dan Holohan: How to size a condensate pump, Dan Holohan: How Frank and John taught me to see, Workshop: Hydronics for High Efficiency Wood-fired and Pellet-fired Boilers. If your boiler has a multiple position burner, that adds an additional wrinkle to setting the pressure controls. To get to Cut In you have to subtract the differential from the main. So set the differential for 1 psig. It's 200 feet wide, 100 feet deep and five stories tall. I asked who changed the control settings since we were there last and he shrugged his shoulders. This will cycle the system between 1/2 psig and 1 1/2 psig as long as the thermostat is calling. So 12 psi is the typical "cold" pressure for residential boilers. Can someone direct me as to the proper settings for a Honeywell Pressuretrol installed on a residential steam boiler. Fill the loop with water when you are done. Well, lets consider the square foot of equivalent direct radiation (EDR). The Location of a boiler pressuretrol is the top pressure side of the boiler. 4 Tips To help ReduceFreshwater Consumption On Ship. A boiler's pressuretrol is a mechanism that measures how much pressure your boiler is creating with air and steam. In an additive system, this is lower PSI range where the system is to cut in. What should a pressuretrol be set at? There is a screw on top above that scale which you can turn to adjust the setting. First, know that the pressure the steam-heating system needs depends on the size and condition of the steam pipes and the amount of steam flowing though those pipes. You can set this between 3.0 and 15 PSI. The burner will modulate between low and high firing rates depending on the steam pressure inside the boiler and where the modulation control is set. If you have a vaporstat, consider yourself lucky. Thanks. For example, say you want to maintain 80 PSI. Youre going to look like a hero every time. Most boiler feed pumps are designed to operate with condensate temperatures less than 200. The setpoint on this control is set higher than the operating pressure control. In other words, if we have 1 psig pressure at the boiler, well have 12 ounces at the radiator. (The number 1 should be visible in the middle of the visible portion of the thumbwheel.). of pressure. And thats how you set a pressuretrol. Then verify that it comes back on before the thermostat is satisfied. Understanding Steam Boiler Pressure Controls - SteamWorks - YouTube 0:00 / 4:41 Intro Understanding Steam Boiler Pressure Controls - SteamWorks powermechanical 9.35K subscribers Subscribe. It is one of those controllers where the mercury has to make contact with the wires to keep the current active, and it is currently set so that once the pressure exceeds 10, the tumbler that holds the mercury flips the other direction and shuts it off to prevent the boiler from exploding or whatever other disasters occur when that happens. The boiler manufacturer would have set the slope to the boilers capacity and i recommend NOT adjusting it without a proper Technicial or PE to say so. Thermostat is working fine. However, the operator control is not the same as the boiler steam pressure setpoint. What kind of sales do you expect in 2023? They have two parallel vertical scales and adjustment screws. Product information Technical Details Additional Information Warranty & Support This device keeps your steam boiler from building up so much pressure that it explodes. Base your pressure drop on that corrected equivalent figure. Unlike the operation control, the modulation control is not a two-contact circuit. If the boiler has this type of burner, I will set the firing rate control for the desired pressure, ten psig. Also note If set the differential pressure too wide, your steam pressure might drop lower below the temperature you require for your operations, therefore make sure to keep little rang. This control is almost identical to the operator control in terms of function. That means we should be able to get steam to the end of the 200-foot run with just two ounces of pressure. Your email address will not be published. It's nice to hear about a boiler that's working good for a change. Sounds like you got a good installation and the boiler is doing what it should be doing! Literature, diagrams and more information for Pressuretrols. That means we should be able to get steam to the end of the 200-foot run with just two ounces of pressure. High fire is the maximum amount of fuel burned and low firing the A boiler should always start off in low fire and shut off in low fire. If you put more pressure than that into the radiator, youre wasting money and probably going to screw up the system. lb. Differential. And now we know we need about 1 psig at the radiator. The system will now operate between 1/2 psig and 1 1/2 psig whenever the thermostat is calling for heat. The burner stays off until the pressure inside the boiler drops to the differential (2 psi) setting minus the setpoint. I see settings ranging from 2 to 14 lb. It means that in a one-pipe system, if you start with 16 ounces of pressure at the boiler, you will have about 15 ounces of pressure 100 feet down the line, and so on. How high is too high? An example of an additive control is the Honeywell PA404 Series of controls. One scale is the main pressure scale the other is the differential. It solves the shortcomings of using traditional large boilers, long steam supply pipelines, high heating loss and wet steam. All Rights Reserved BNP Media. If your inclined to learn more pick up a copy of TLAOSH - The Lost Art of Steam Heating. fig. (The number 1 should be visible in the middle of the visible portion of the thumbwheel.) And thats how you set a pressuretrol. Any help is appreciated, That reset button is used to override a safety cutout of some kind. Contact Us or Read Privacy Policy. Have your product or service seen by tens of thousands of heating professionals every month. I will run down and return the Pressuretrol to the settings you suggest. If we add those two numbers together, well have our pressuretrol cut-out setting, which in this case will be 1 1/2 psig. Pressuretrol Steam Pressure Controllers from Honeywell Pumps Boiler Feed Pumps Condensate Pumps Fuel Pumps Hydronic Pumps Sump Pumps Vacuum Pumps Steam Traps Cage Units Float & Thermostatic Traps Inverted Bucket Traps Liquid Drain Traps Radiator Traps Thermodynamic Traps Thermostatic Industrial Traps Testing Equipment Steam Trap Parts Adapters Set the vaporstat to Cut In at about 4 ounces and Cut Out at about 10 ounces after making sure that all the air vents are the right size, in the right places and working properly. Next, consider what defines the term EDR. I usually set it for two psig. This control is there as the last resort protection in case of a runaway boiler. And now we know we need about 1 psig at the radiator. The pressuretrol is an important safety device in a steam boiler because it helps to prevent overpressure and ensure that the boiler operates within safe limits. A cut-out of 1.5 is as low as you can get with a Pressuretrol. These three main controls are the operator, modulation, and high limit pressure controls. Its 200 feet wide, 100 feet deep and five stories tall. The main scale -- the one on the right -- is OK, but the differential scale -- the one on the left -- isn't. Dan Holohan and his wife, Marianne, founded www.heatinghelp.com in 1997. Set that scale at 1 1/2 psig. Unless youre sizing the piping from scratch (and few do that these days), you can assume the guy who did size them based his calculations on a pressure drop of 1 ounce of pressure loss per 100 feet of run for one-pipe-steam systems, and 2 ounces of pressure loss per 100 feet of run for two-pipe systems. You can set it anywhere from 0.5 lb. Set that scale at 1 1/2 psig. One scale is the Cut In setting, and the other is the Cut Out setting. You should feel a little pressure until you get the water out of the loop back into the boiler. The operator control will shut down the boiler to prevent too much steam pressure from building up. Pressuretrols dont come with screwdrivers, but most contractors already have their own screwdrivers, so thats okay. Pressuretrol limit controls are high pressure limit switches which break electrical circuits when pressure rises to a preset value. Although, using a Cyclegard moves the tripping function from one safety device to another. 20 psi is typical for U.S. / Canadian residential heating systems normal hot . The pressuretrol (Honeywell PA404? Copyright 2023. weather prattville alabama. All models automatically reset and have an adjustable differential. A vaporstat is a very accurate (and more expensive) control that senses ounces of pressure rather than pounds. When the pressure reaches to 250 psi, it will shutdown the boiler. I do not want to run it up to the top of the scale as I am a bit skeptical of the accuracy at the far ends of the range. This is a safety factor and it means that in our example, we only have to have 1/2 psi (or 8 ounces) of pressure at the boiler to get the steam to the furthest radiator. The limit control system normally, has small Manual Reset button inside or on top of the cover. The Pressuretrol should actually be a safety devise and should not have to control the pressure in a system that is properly sized. Honeywell pressuretrol controller with a range of 2-15 psi (adjustable 2-6 psi differential range), and a 1/4" NPT female connection to siphon loop (included). Another consideration is the flash steam will find its way to the boiler feed unit and escape through the vent. Allowing for turns in the basement, lets say we have to travel 150 feet to get to the base of the riser thats furthest from the boiler. The problem, however, is that most of those screwdrivers turn in only one direction: clockwise. I'm not an expert on steam heat but I did specify certain piping for the installers such as the very high risers and header (much more than the recommended 24") and the addition of main vents, etc. Same Pressure, Different Energy, How to Take Your Boiler Room from Good to Great. On-off steam systems for comfort heating are usually set for an average of 2 lb. Set the operator to 88 PSI and set a 5 PSI differential so that the boiler will shut off at 88 PSI but will start the purge cycle when the pressure drops to 83 PSI. This standard boiler pressure control with an additive differential is an automatic reset control used for setting the desired boiler operating pressure. That means that were basing steam EDR on a pressure slightly less than 1 psig at the radiator. Add the height of that riser and we wind up with a longest run of about 200 feet. turn the screw on the top of the unit counter-clockwise until the pointer is at the bottom of the scale, remove the cover and rotate the white thumbwheel to the right as far as it will go. If you have a steam boiler youre also going to have a pressuretrol. Pigtail i clean a month ago. Photo credit: Ray Wohlfarth, This boiler pressure limit control is a manual reset control and requires pushing the red button on the front to resume boiler operation once the boiler pressure drops. 10 Important Things To Check During Electro Hydraulic Crane Inspections, Latest Fuel compatibility and stability testing 1, 3 Nigerian Stowaways landed in Ghana port instead of Spain. Pressure gauge reading as high as 12psi even when boiler is not firing. Then set the differential (or diff) wheel at 1 psig. But that doesnt allow for the fittings and valves, does it? The Additive type control is a bit different to set and adjust. Copyright 2019 boilerspecialists.com All right reserved. female pipe threads Once the pressure reaches a set point; for example 8 PSI, the boiler burner cut off (stop). Even if you don't want to spin the wrenches yourself it will give you the knowledge to direct the guy that does spin the wrenches. I would set the operating control slightly higher, to operate between 2 and 4 psi and the firing rate or modulating control to operate between 1 and 3 psi. That, by the way, is why standard pressuretrols have a minimum cut-in pressure of 1/2 psi. A sequence of how these controls work is as follows: You start the boiler and allow the pressure to build. I am a bit leery of going to close to that setting and causing it to open and lose all our steam. It can manually be reset by pressing reset button at the top. (Im not 100% sure he changed it, and if so, Im not sure why either.) I flushed it out 4-5 times this week, filled it with fresh water and Rector-seal 8-Way Boiler Treatment, and then skimmed it. Design, CMS, Hosting & Web Development :: ePublishing. So to figure the correct pressuretrol cut-in setting, well use an old-timers trick. I adjusted the operating pressure control to the normal steam pressure. Remove the outer casing of the Pressuretrol Controller to access the differential dial using a screwdriver. Well set the boiler right in the middle of that building with two mains, one going to the left, and the other to the right. Honeywell proportional pressuretrol controller with a range of 0-15 psi, non-adjustable, one potentiometer, and a 1/4" NPT male connection to siphon loop. Weil Mclain EG-55 steam boiler. Can it be higher? Set the Pressuretrol "Main" to "1" or 1.5 and the Differential to .5PSI. Honeywell pressuretrol controller with a range of 10-150 psi, manual reset, and a 1/4" NPT female connection to siphon loop. He loves hearing from you! This will cycle the system between 1/2 psig and 1 1/2 psig as long as the thermostat is calling. Honeywell pressuretrol controller with a range of 5-50 psi (adjustable 4-12 psi differential range), and a 1/4" NPT female connection to siphon loop (included). The last control you will have on your boiler is the Limit Control. A vaporstat is the nicest present you can give many smaller steam systems. The main setting is accessible from the outside of the controller, but the differential is often located inside the controller box, and typically the cover must be removed by removing a screw to access the differential control. I have to keep pushing the reset button, the frantic school custodian said when I answered the phone one cold January morning. By closing this message or continuing to use our site, you agree to the use of cookies. Click to enlarge and you can see the actual pressure settings on the steam boiler control shown at left. Many customers and contractors will bristle when I ask them to try setting the boiler to 2 psi. This allows a more consistent pressure and temperature for your process. Do subscribe to our newsletter and share with friends who might found this article interesting. They made sure those radiators would be big enough to heat the rooms on the coldest days. Honeywell pressuretrol controller with a range of 10-150 psi (adjustable 10-22 psi differential range), and a 1/4" NPT female connection to siphon loop (included). You can have it good, fast or cheap. Table shows present examples of cut-in, differential, and cut-out points thats howpressuretrol works. This website requires certain cookies to work and uses other cookies to help you have the best experience.