ACS Essentials - How a Multifunction Valve works

[@djFridd]

I have my ACS next week and your videos are really helping. Thanks

[@FaceSlider750]

Thank you for all your videos. Here’s a comment to help support.

[@passyourgas]

Thanks for the comment. I’m glad my stuff helps you. Good Luck. 🙏

[@barry6873]

hey drew you ok ,,i bought that RD TRELORR book its realy good actualy nice reading about the gas how its formed over milions of years think im becoming a bit of a gas anorak wich is surprising me lol ,,ive given a mate of mine a link tou your channels as i told him you are very realy great with the videos ,,the video you done when you said bay checks in the assesment ,,i made a note of all the things you said and it was realy good because i reffered to it in the exan]m wich in turn made me relax and get through the practical exam ,,you dont realise how much i appreciate yoiur help thanks so thank you again ,,Barry

[@passyourgas]

Barry.. I’m glad I could help. And I’m glad the bay video steadied your nerves. I’ve seen so many people start wrong, and it only goes downhill from there. Congrats, I’ll speak again in 5 years at your recertification when you’ll have forgotten everything you know now😃. Glad you enjoyed the book.

[@CarlGuymer1]

Very good thanks

[@passyourgas]

Thanks Carl. 🙏

[@cazza1295]

So if this was in a boiler where is the temperature phial going back to

[@passyourgas]

Hi Cazza..it would sit in the flame just like it does in a cooker. Remember an FSD is only there to detect the presence of a flame, nothing else, so these phials must be in the flame to detect its presence. When the flame goes out the phial cools and closes the gas valve. If you watch my cooler video you’ll see exactly how it works. Cheers I hope that helps.

[@cazza1295]

@@passyourgas hi, I mean how does the thermostat on the boiler control the burner, I know that In a cooker the phial expands and then closes the main supply of gas and leaves a bypass rate for low flame, so on a boiler does the thermostat phial expand and control the solenoid valve in the multifunction control valve? and once the boiler is up to temperature does it leave a low flame like a cooker or just a pilot until the temperature drops, in which the burner ignites again ?

[@passyourgas]

Hi Cazza, good question, thanks. I left the temperature control functions out of the video to keep things simple, but there are several ways that this can be done. One is, as you say, to have a separate thermostat system only acting on the solenoid but leaving a small weep line through to the pilot. This is called a “modulating” system where the heat keeps coming on and off. Other systems are directly linked to a servo ( a small motor) inside the Multifunction valve that adjusts the regulator pressure automatically according to how hot the appliance is getting (using a circuit board). In real life you will nowadays come across fan driven burners that blow forced air to the burner and the circuit board adjusts the speed of the fan to change the temperature inside the appliance. It all depends on the system within the appliance. You won’t need to know the specifics of how heat is actually controlled to pass your assessment or exams, although you will have to learn it to be a good and efficient engineer. You will, however, be taught about forced air burners and their operation. I hope that helps.

[@vconsenheim]

I like

[@passyourgas]

Thanks Vincent.