mobeewan wrote:
Something you might consider, the single stage regulator may be all you need as long as you do not need to burn more than 70,000 btu/hr worth of propane at any given time. The black acme nut on the single stage regulators are only rated at 70,000 bth/hr which is considered low flow and typically run only one appliance at a time. You might be able to operate 2 appliances inside the trailer at the same time, but not both running full blast at the same time. I doubt the water heater and furnace will run at the same time.
The green acme nuts like on the pigtails commonly used with the dual stage regulators on trailers are rated for 200,000 btu/hr and are considered medium flow. They allow higher flow for running multiple appliances at once.
Lastly, red acme nuts are rated for 400,000 btu/hr. The only place I have seen the red acme nuts in use was on a Papa John's vending trailer used to serve the shipyard here for lunch time vending. I walked by it in the shopping center where the store that operated it is located. It was an enclosed trailer the size of a race car trailer. It had 6 - 40 lb propane cylinders mounted on the front with 3 dual stage auto change over regulators. Each regulator was connected to 2 propane cylinders. That set up allowed 1,200,000 btu/hr of propane flow available for the pizza ovens and warmers inside.
Slightly off topic but:::
All the fine print about these Acme nuts is so much BS. Yes, they're supposed to work that way but in reality, they are all just junk. the BTU restrictor is simply a ball and a spring. The angle the fitting is at changes whether the ball is not effected by gravity or is helped or hindered in closing at high flows by gravity. In addition, the springs get tired after use so the restrictor closes more easily and you get limited flow under the same conditions where before you had full flow. The whole operation was created by the hand wringers to prevent the idiots from making stupid mistakes. When you hook up a "compliant" LP system you'll have 2, 3, 4, or more of these restrictors in line all waiting to cut flow when you want it or need it. My solution? Apply a reasonable sized electric drill and bit to the tip of the LP spud and drill out until the spring and ball drop into your hand. THEN, repeat for all spuds in the system. Result? A system that works well without a mess of problems wherever you are and you don't really care what color the Acme nut is. BTW, similar issues exist in the OPD valve on SOME 20# LP portable bottles, Some of these valves have a built in flow limiter and some don't, but these can't be fixed the same way. Again, overkill by the hand wringers and worry warts because one idiot made a stupid move and got what he deserved for not paying attention as he should have.