How does a natural gas regulator work

okay this is the gas pressure regulator used for natural gas can be used for propane too uh not particularly this one but different ones can be used a gas comes in here and is regulated out here probably coming in about seven inches of water column here coming out here from where from one to four inches there depending on the equipment parts on this thing this is a valve here this is attached to this diaphragm and it opens and closes against that spring okay this is the spring this is an adjustable spring just by this nut up here the spring presses down on the diaphragm now here's your diaphragm here and it's attached to that rod that is pressed down by the spring above and this the rod is also connected down here to this valve so when my gas comes in here the spring will get a little wider there so we can see that whole thing again okay the spring presses down on the diaphragm here which opens this valve once my water column pressure comes in here it passes through this valve pushes on the diaphragm and tends to close the valve now it's pushing against the spring if you look close you can see that spring compressing there now you can see as i move this this spring is going to compress and it this valve down below there as the pressure comes in here this is open because we're empty throughout the rest of this so as the pressure increases then it increases on the diaphragm and the diaphragm closes off the valve now if the pressure downstream that is here and if you note this passage goes right up into where the diaphragm is this is your outlet so if this pressure here reduces then that reduces the pressure on this diaphragm because this valve is closed there's no gas allowed in there so as that reduces then this begins to open and when the pressure gets up to the whatever the spring is set for then it modulates somewhere in here because the pressure in here is the actual pressure on the diaphragm and this is regulating how much gas can pass through and at what pressure now let's kind of make up how this would work this would be closed when the machine is off because we have enough pressure in here to overcome the zero pressure here okay the gas valve opens and gas passes out here that's going to reduce the pressure in this diaphragm in here as that pressure reduces then the spring is going to take over and open so gas is going to rush in to pressurize the diaphragm again it's going to tend to close now depending on how much gas is passing out of here that that will regulate how much this valve is open because as it opens it increases the pressure on the diaphragm which tends to close the valve and as it closes it decreases the pressure on the diaphragm and it tends to open again very simple little valve these operate these increase the downstream pressure by the adjustment of the spring now this spring adjustment is trying to open the valve so as the spring adjustment opens a valve and pushes down then the valve allows more gas to the diaphragm which tends to push it back closed again so it reaches a balance if i wanted less pressure i would counter clockwise this and that would give less spring tension here which would mean less pressure inside here if i turn it down and put more spring pressure on it then there's more pressure trying to push this valve open and my downstream pressure will increase that's pretty much in a nutshell what the gas pressure regulator does a couple other things about this regulator we have here a small orifice now this orifice is very small and this needs to be piped either outside or to the pilot light because it's possible this diaphragm here could get a hole in it and we need some way for it to breathe anyway up here we can't have pressure building up on top of the diaphragm so it has to be able to breathe out through that hole the problem is if i get a hole in this diaphragm i don't want a whole bunch of gas coming out of this bleed hole so they make a very small hole in it and i'll show you a picture of that remember that bleeder i talked about before well if you look real close in there you can see a hole in that bleeder that bleeder is very small very small hole because if this diaphragm here were to burst they don't want a whole pile of gas going through this bleeder so they put the little hole in there so it limits the amount of gas and come through very dependable uh part seems to pretty much last forever certainly if the diaphragm were to puncture then uh that would cause problems however uh you'll get a gas smell wherever that pipe goes out of course it goes out to a pilot or something like that at least it'll burn it and it would be seen on a service that there was a problem there but always remember adjusting these regulators you adjust clockwise to increase the spring pressure which increases the pressure on this valve which increases the downstream regulated pressure these will hold a very steady pressure for many many years and that is the pressure regulator

Channel: grayfurnaceman

Views: 629,224

Keywords: regulation, of, natural, gas, 3.5, inches, water, column, diaphram, valve, leak, fire, burner, Burn, manifold, pressure, Burning, Flame

Id: n4DDnoMAHY8

Length: 8min 37sec (517 seconds)

Published: Sun May 06 2012