Need help with shop heater gas conversion

[sledsuperman]

I have a shop with a Modine (model PD125AA0111)heater that is currently set up for propane. Last year I ran the heater off of propane bottles and just recently ran a natural gas line run to the shop and need to convert the heater to natural gas. The Modine heater originally was set up for natural gas but before I bought it someone converted it to propane. Now I need to convert it back. The specs on the side of the heater give me the orifice size for 0-2000 ft elevation. I am at 4500 ft. Can I just drill out the existing orifices to the specs on the heater for natural gas?
For the gas valve (Honeywell VR8200A 2900) I need to change the spring and adjust the pressure. Right? I while ago I took some parts out of a home furnace that someone was junking so I have a gas valve spring and orifices for natural gas. The orifices don't fit my shop heater so I cant use them. Will the spring work for the gas valve in my shop heater? I don't know if the gas valves are the same make or model. Any other coaching on adjustments are welcome. - Thanks
My wife's grandpa did this stuff as a career and gave me a bunch of related tools that I kinda know what to do with but I'm not sure about what I'm doing. I'm sure that he could help me if he were here.

 

[Mafesto]

I would suggest getting these answers from Modine, or a Modine retailer.
Good choice by the way! I have a couple of Hot Dawgs in the shop & garage.

 

[bholmlate]

I will second what Mefasto said. Espeically dealing with things that can make big giant mushroom clouds if they are done wrong.

 

[Mafesto]

I will second what Mefasto said. Espeically dealing with things that can make big giant mushroom clouds if they are done wrong.

See, there's always something we can agree on!

 

[Mafesto]

Having a discussion about heat source options, and as long as I have done some research I thought I would share my findings in hopes it helps someone else.


one Therm = 100,000 BTU
one gal LPG = 91,000 BTU
one gal gasoline = 120,500 BTU
one gal diesel = (approx) 138,000 BTU
one KW = 3,412 BTU
one lb coal = (approx) 9,811 BTU
one gal LPG = 4.24 lb
100 lbs LPG = 23.5 gal

Taking it a step further...
at $1.80/Therm Nat Gas costs $1.80 per 100,000 BTU
at $2.50/gal Propane costs $2.75 per 100,000 BTU
at $.12/KW Electricity costs $3.51 per 100,000 BTU
at $2.50/gal diesel costs $1.81 per 100,000 BTU

Obviously local prices vary and some fuels fluctuate more than others

 

[wwracer]

I would suggest getting these answers from Modine, or a Modine retailer.
Good choice by the way! I have a couple of Hot Dawgs in the shop & garage.

Yep... Hot dawgs are pretty much the gold standard. With that said I agree, I'll mess around with most anything mechanical, but dicking around with pressurized LP gas mods... yeah, no, not so much