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What's the point of the pressure regulator in a gas range?

I don't think you're understanding.
2 PSI is considered high pressure for residential.
Gas companies supply is higher pressure to the meter outside of the structure. It gets regulated down to around 7" wc outside. Some newer systems regulate down to 2-5 psi and run smaller tubing inside to save money on pipe and labor. Each gas appliance has its own regulator to bring the pressure down to that 7".
Propane is 11 to 13".
I don't know what gave you that impression. I am excluding 2PSI systems and talking primarily about LP systems with an 11" WC domestic supply pressure.

And I'm asserting that my LP water heater control valve just turns that 11" supply pressure on to the burner and does not contain a pressure regulation function that operates to down regulate the pressure during normal use.
 
Yes you are correct. All gas valves have some regulation, but that's not their primary function. Sometimes terminology gets in our way.
11" to 14" is standard for propane. Any readings below that can cause problems. You should always measure that at the manifold for accuracy.
 
All gas valves have some regulation
This is where I disagree.

We can say that an on off valve "regulates" the gas flow to a water heater to heat the water to the setpoint. In that sense, it is a regulator.

We can say that a burner orifice "regulates" the gas flow into the burner, and in that sense, every appliance's orifice is a regulator.

But in the terminology of a "regulator" as referring to a diaphragm that downregulates pressure to an atmospheric reference point, I still don't see evidence that my water heater contains such a regulator. There is an atmospheric reference regulator on my tank, to set the line pressure, and there is an atmospheric reference regulator in the range, we can see it's diaphragm. I see no atmospheric reference regulator in the water heater's control valve yet.
 
I do see that diaphram regulators are built in to some, many, or all forced air furnace regulators, such as the Honeywell VR8200. And they have a regulator pressure adjustment screw as any standard type diaphram regulator does. I don't have any forced air furnaces though, and I've never worked with these.
 
This is where I disagree.

We can say that an on off valve "regulates" the gas flow to a water heater to heat the water to the setpoint. In that sense, it is a regulator.

We can say that a burner orifice "regulates" the gas flow into the burner, and in that sense, every appliance's orifice is a regulator.

But in the terminology of a "regulator" as referring to a diaphragm that downregulates pressure to an atmospheric reference point, I still don't see evidence that my water heater contains such a regulator. There is an atmospheric reference regulator on my tank, to set the line pressure, and there is an atmospheric reference regulator in the range, we can see it's diaphragm. I see no atmospheric reference regulator in the water heater's control valve yet.
This is correct.
The term "regulator" is used incorrectly.
A gas valve can be two position, modulating, or multiple position.
A pressure reducing valve reduces the incoming pressure to what is acceptable on the out going side.
The terminology is important but incorrectly used much of the time.
Maybe I'm not understanding your base question.
 
This is correct.
The term "regulator" is used incorrectly.
A gas valve can be two position, modulating, or multiple position.
A pressure reducing valve reduces the incoming pressure to what is acceptable on the out going side.
The terminology is important but incorrectly used much of the time.
Maybe I'm not understanding your base question.
Might be agreeing then. Anyway, base question here is really just what's a typical manifold pressure at the burners of an LP range.
 
Propane around here is generally set for 11" to 14" WC. We always measure that at the manifold. Anything outside that range usually will cause issues.
But remember that oxygen is also a determining factor. Which is a whole other conversation. 😉
 
Propane around here is generally set for 11" to 14" WC. We always measure that at the manifold. Anything outside that range usually will cause issues.
But remember that oxygen is also a determining factor. Which is a whole other conversation. 😉
Kohler Canada used to set the regulators for Propane powered generator at that too...
I assume it was the standard for all Propane but you are the first person I ever heard repeat that..
 
When they put in the natural gas line to the sub division they offered free conversion from propane for up to 5 pieces of equipment - so I let them do it verse me doing it. All of my appliances were bought as natural gas, but converted to propane with the official kits.

For the furnace there are several diaphragms that adjust things for my altitude along with the 6 burner orifices, he drilled them out.
For the fireplaces he drilled the orifice out and tweaked the regulator spring about 1/2 turn
For the dryer it was drill the orifice out and remove the shield that was added when it was converted.
For the water heater of 1999 vintage he drilled the orifice and tweaked the gas valve ... remove little plastic cover, turn a screw, put the cover back on and watch the flames a minute.

The tweaks on the springs was done to turn the flame from yellow to blue while he watched.

I actually had to replace the gas valve on the water heater at one point...went on vacation and turned it off, when we got back it wouldn't turn on... turned out white & rodgers had a recall on tha valve... they offered to send a plumber, but I just told them send the valve.... took 20 minutes to unscrew the old one and screw in the new one then leak check the gas lines.

So,

If you are planning on doing a LP to natural gas conversion - almost everything just needs the orifice enlarged slightly. The guy doing the conversions had a small drill bit inside a wirenut and did them all by hand. Google says it is a #65 or #70 drill bit.... I know I watched dad do the conversion on the dearborn heaters when I was growing up... we were given them as people upgraded to central heat and air.
 
Line pressure is usually set higher than manifold pressure, and the appliance has a flow regulation built into the controls.
I would be very surprised if a water heater gas valve didnt regulate the flow to the manifold.
On LP systems it is common to have the line regulator set to output 14" to the appliance line, because the appliance regulator adjusts it down to the 10" manifold pressure.

I am not a plumber though.
 
Line pressure is usually set higher than manifold pressure, and the appliance has a flow regulation built into the controls.
I would be very surprised if a water heater gas valve didnt regulate the flow to the manifold.
On LP systems it is common to have the line regulator set to output 14" to the appliance line, because the appliance regulator adjusts it down to the 10" manifold pressure.

I am not a plumber though.
I bet you stayed at a holiday in express last night though ;)
 
Simple pressure regulation of a gas is trivial, The "doo-dad" on your propane/gas grill where you connect to the tank is a pressure regulator. There will be something similar on every single gas appliance of any flavor. It's a simple mechanical spring loaded chamber. Identical in engineering to a water pressure regulator only with springs/diaphragms suitable for a lightweight gas. You have to have a relatively precise known pressure to control the flame for anything that you are burning. Be real, we've been doing this for over a century, it hasn't really changed much.
 
The "doo-dad" on your propane/gas grill where you connect to the tank is a pressure regulator. There will be something similar on every single gas appliance of any flavor.
The barbecue regulator goes from tank to barbecue pressure. The residential propane tank regulator goes from tank pressure to 11" line pressure.

The assumption that every device in the home has its own diaphragm regulator from line pressure to manifold is not so simple or clear.
 
The barbecue regulator goes from tank to barbecue pressure. The residential propane tank regulator goes from tank pressure to 11" line pressure.

The assumption that every device in the home has its own diaphragm regulator from line pressure to manifold is not so simple or clear.


Depending on the needed flow that diaphragm regulator can be the size of a dime or the size of a silver dollar... They all have something built in or on.

The large unit outside the home steps down from line pressure using a diaphragm to get an output pressure that is standard for residential and compensate for relative pressure around the house... i.e. I live at 9000ft and my pressure is only around 11.2 PSI where at sea level the pressure is 14.7 psi. They would also compensate for pressure changes due to the weather - i.e. a shift from 28inhg to 31inhg ... standard sea level pressure is 29.92inhg...

There is a lot going on in the outside units on a house including the meter than counts how much gas you use.

Interesting fact - the gas company once scheduled with me to swap out the meter - they are required by the PUC to send in X number of meters every year to be calibrated and check that they are counting correctly.

My furnace is 90,000 btu, the dryer is 22,000btu, the water heater is 60,000btu, the stove is 9k btu per burner and 18k for the oven part. A gas grill can be between 10k and 40k depending on the grill...

Vast difference is amount of gas to burn to heat the various appliances burn so a large difference in diaphragms and regulators....

My furnace has a 3/4" pipe... the water heater is also a 3/4" pipe... the stove is 1/2" and the dryer is 1/2"... this affects how much gas can flow... when I recently had to replace a leaking flex line I used 5/8" for the furnace that was rated at 120k btus.

And the diaphragm size for a grill is almost always propane and is sized depending on how many items are connected. My old grill had a burner on the side plus 4 of the burners in the grill area. There were 2 lines from the grill and two regulators - one to the burner and one to the grill area.

I am pellet smoker now.
 
The barbecue regulator goes from tank to barbecue pressure. The residential propane tank regulator goes from tank pressure to 11" line pressure.

The assumption that every device in the home has its own diaphragm regulator from line pressure to manifold is not so simple or clear.
It's not an assumption. It is a requirement. I haven't used NG in over 10 years, but I think many modern devices have additional safety devices that detect problems and shut down. I don't think there is any devices available today that actually run a pilot light, they all have piezo igniters. They have passive flame detection and will shut off if it doesn't light. There is some sort of pressure regulator between the feed and the flame on every gas device period. It may be integrated into some other control, but it's there.
 
It's not an assumption. It is a requirement. I haven't used NG in over 10 years, but I think many modern devices have additional safety devices that detect problems and shut down. I don't think there is any devices available today that actually run a pilot light, they all have piezo igniters. They have passive flame detection and will shut off if it doesn't light. There is some sort of pressure regulator between the feed and the flame on every gas device period. It may be integrated into some other control, but it's there.


Flame detector can be just a current carrying probe to complete a circuit... a thermopile to generate a few hundred microvolts, or a pilot tube that is just a hollow tube and back at the valve it hooks to a pressure switch to allow the valve to turn on... ...

My fireplaces are the only thing in the house that have pilot lights. They have both the pitostatic tube and the thermopile.... The microvolts from the flame power the valve and also let the wall switch work to turn it on and off.....

Another intersting note - a lot of installers of gas fireplaces use a generic wall switch.... but because the voltage is 180ish microvolts as they age you can have trouble with them turning on.... you can clean the thermopile with 0000 steel wool... and you can replace the switch with one that has gold contacts inside to help with the oxidation....
 

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