Propane Regulator - single or dual stage?

[s/v Jedi]

I would opt for a dual stage for safety. Also, if you are in colder climate, the dual stage largely prevent freezing the regulator.

I bought my "marine" dual stage regulator at the West Marine or similar chandlery so normally available in the USA.

[sandiegoskipper]

The primary advantage to using a dual stage regulator is to prevent frosting up and the resulting clogging of a single stage. The two stage makes two pressure drops while the single makes one large one, and as we all know, when a liquid becomes a gas, cooling occurs. This frost/freeze-up occurs more frequent when temps are low, humidity is high and gas thru-put through the regulator is high. If you have the room, spend the extra $10 on a two stage.

Skip

[geoffr]

All,

Thanks for the wonderful feedback - I have decided on a single stage as that is what I had before ... and freezing over is not a problem (no plans for arctic or cold water cruising!).

[donradcliffe]

The single stage fits the KISS principle.

[Cheechako]

Originally Posted by geoffr

All,

Thanks for the wonderful feedback - I have decided on a single stage as that is what I had before ... and freezing over is not a problem (no plans for arctic or cold water cruising!).

The freezing has nothing to do with the outside weather, it's part of the liquid to gas expansion.

[Cadence]

Originally Posted by Cheechako

The freezing has nothing to do with the outside weather, it's part of the liquid to gas expansion.

I've never had a freeze problem with LP, I'm guessing you need a lot of demand at one time. Put a regulator on a CO2 tank and watch it freeze.

[pcmm]

Lived aboard for 5 winters in Canada and never had an issue with single stage regulators freezing up. But then we were just running the stove from it. Heated with diesel instead!

[Cheechako]

Originally Posted by Cadence

I've never had a freeze problem with LP, I'm guessing you need a lot of demand at one time. Put a regulator on a CO2 tank and watch it freeze.

Yeah, I've only had it occur on the home BBQ. I suppose it might on a stove that is going on all burners.

[sailorchic34]

Originally Posted by Jammer

It's complex but there are multiple safeties. In the U.S., for indoor residential propane, the traditional arrangement is a tank regulator that drops the pressure to 10 PSI, then a regulator on the outside of the house that drops the pressure to 14" w.c. (about 1/2 PSI). Newer installations use a third regulator by dropping the pressure to 2 PSI on the outside of the house and then using an appliance regulator set at 14" w.c. This allows smaller line size in the house.

Under CGA (Compressed Gas Association) regulations, which govern U.S. installations, the regulators must be designed to fail closed in the event of a spring failure. They must be vented to the outside to reduce the fire hazard in the event of a diaphragm rupture. Appliance regulators are the exception and instead use vent limiters. They can fail open in the event of diaphragm rupture, but the intermediate pressure is 2 PSI and CGA regulations require appliances to withstand 2 PSI.

With natural gas the situation is roughly similar but the pressures are slightly lower at the appliances, again, newer installations usually use a 2 PSI distribution and an appliance regulator. There may be multiple stages for the regulator on the outside of the house (or rarely, in the basement or underground), depending on the supply pressure in the area.

While many newer condo's/apartments do use 2 psig gas distribution, most single family homes still tend to have distribution at 7". I've designed it both ways. I have designed NG and propane systems for about 45 years including gas distribution systems to over 1500 mmbh with 7" to 5 psig to 50 psig gas pressure.

As to which building codes govern gas installations in the USA, it depends. NONE use CGA. CGA is not a building CODE. CGA is a trade association of gas equipment manufacturers. Gas codes are specified in the uniform and international building codes (which is not international). These codes use design information from NFPA 54 for natural gas and NFPA 58 for Propane. Yes, I know them all too.

Having designed projects from 9000 sf single family to billion dollar projects, for a boat of less then 60 feet ish, a single propane regulator will more then adequately control supply pressure to a stove and propane heater. Gas regulators are extremely reliable and are designed to fail safe.

BTW, I am not a fan of vent limiters. I have used them, but would not use one in my own home or boat, due to flare up issues and that they do not fail safe.

BTW2 Freezing of propane regulators is a non issue as is wire drawing valve seats. Nether happens under normal conditions. Wire drawing of valve seats in water regulators is an issue, just not so much in gas regulators that use a rubber diaphragm to control supply pressure to fractional psi levels.

[sandiegoskipper]

I haven't designed big gas projects but I had to install a dual stage regulator on my NG home BBQ due to freezing up of the single stage unit. And that's in San Diego in the warm dry summer and with one burner unit on high.

Also - FWIW - home water regulators use rubber diaphragms and springs just like gas regulators do - but the regulator freeze-up actually blocks the tiny hole the gas comes through. The diaphragm and the spring continue to function as designed, but with no pressure behind them they just sit there...

Skip

[davil]

question on pressure gauge
Am converting from natural gas (prior system) to propane.
all is adapted including new hoses,regulator,solenoid etc,however am looking at the old pressure gauge used for natural gas and looks nice and in good shape,was part of the original natural gas system,could I use it now in the propane line?
thanks

[Cheechako]

Originally Posted by davil

question on pressure gauge
Am converting from natural gas (prior system) to propane.
all is adapted including new hoses,regulator,solenoid etc,however am looking at the old pressure gauge used for natural gas and looks nice and in good shape,was part of the original natural gas system,could I use it now in the propane line?
thanks

I dont know why you couldn't. I tend to like a propane system with as few joints as possible though. I did have a gauge on one boat. One thing I noticed is it didn't give much info, it looked good until you are just about out then dropped fast.

[Cadence]

Originally Posted by davil

question on pressure gauge
Am converting from natural gas (prior system) to propane.
all is adapted including new hoses,regulator,solenoid etc,however am looking at the old pressure gauge used for natural gas and looks nice and in good shape,was part of the original natural gas system,could I use it now in the propane line?
thanks

I would ask someone in the business. MWAG is that the NG is in the tank under pressure where as LPG only has the pressure from evaporation. It may be apples and oranges.

[davil]

The local RV store told me can be used.
Agree on what info the gauge gives,always thought will tell me how much gas is left,but is not true,what I learned with the survey of my current and recent purchase,the regulations (whatever they are)require to have one and use it to detect leaks,like shutting all appliances the pressure will remain unchanged,and like on my case,al appliances shut and the gauge showed a drop.
Since I have it will reinstall it,but I added a solenoid on the line that my boat did not have.
In any case,I am good at opening the gas only to cook and then shut the valve at the tank.

[sailorchic34]

Originally Posted by davil

question on pressure gauge
Am converting from natural gas (prior system) to propane.
all is adapted including new hoses,regulator,solenoid etc,however am looking at the old pressure gauge used for natural gas and looks nice and in good shape,was part of the original natural gas system,could I use it now in the propane line?
thanks

Was this a CNG system or land side natural gas system? If the pressure gauge is upstream of the propane regulator it needs to read to at least 150 psig. Standard tank pressure for propane is generally 100-120 psig.

You may (will) need to change the jets for what ever your connection to propane as propane has twice the BTU rating as NG. So most of the time you must change the jets at each burner in each appliance as well.