Propane gas flow to a generator regarding pipe size issues

[blackhat]

Using assumed but safe numbers for your furnace size etc, the line size is marginal but adequate.  I would speak to your propane supplier and confirm your regs are adequately sized and have a pressure drop test done on the genny while everything else is firing.  It should have had this done at start up.

[frule]

Using assumed but safe numbers for your furnace size etc, the line size is marginal but adequate.  I would speak to your propane supplier and confirm your regs are adequately sized and have a pressure drop test done on the genny while everything else is firing.  It should have had this done at start up.

Thanks for your effort! By a pressure drop test, do you mean just using a manometer? The generator has a port. I can do this.
Also, we rarely use the gas range and never use the gas log set, so that's got to help.
Thanks!
Fred

[blackhat]

Yes. Connect a manometer to the inlet test port, record the pressure reading, start and load the genny and start the furnace, water heater and the range. Make sure the genny is near full load and record the inlet pressure. Minimum acceptable at load is about 13" wc if I recall correctly.

[Cdshakes]

Correct. IIRC, the unit has a 1/2" inlet. But I don't know what the internal pipe is.

This is what drives me crazy about the way companies make things.  So the manual says to run 3/4" pipe, but then they give you a 1/2" inlet?  Way to confuse things there fellas!  Why not a 3/4" inlet??

Colin

[blackhat]

The manual says nothing of the sort. The valve inlet is sized based on the size of valve that will pass the required volume of gas. Pipe size is determined by the required volume, initial pressure, acceptable pressure loss, length of piping and a handful of other factors. A unit with a 3/4 inlet may require 2" pipe feeding it if it is 1000' from the gas supply regulator and fed with 1/2 psi gas. If 2 psi gas is available, the pipe run may be 3/4" with a second reg at the unit.