Boiler plate?

   / Boiler plate? #1  

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Metallurgical question for you guys. What is the difference between boiler plate and mild steel plate? I'm in the planning stages of building a wood fired boiler. Thanks!
 
   / Boiler plate? #2  
Back when I was building my outdoor wood boiler or stove.. I looked at all of the brands out there ( many more now ) I was lucky enough to do business with Wood Dr., Central Boiler, Heat-Mor and others. There was another inWisconsin selling Boiler Plate units stating that they were similar to what ships used to use. From what they told me, It was more ductile than regular carbon steel when used in a pressure situation. I looked around there were so many grades with so many ratings I just said the heck with it and used 7/16" mild steel. I used 7/16 because a friend with a roller had some to get rid of. Many of the stove companies use 1/8" MS or 304 or 409 SS. I'm not sure why you would need SS or Boiler Plate because most stoves are completely surrounded with water and rarely get hot enough to boil the water. That's why yhey last so long and mine has no pressure buildup at all. Use anti corrosion in the water and try to keep the stove as hot as possible to battle creosote. I looked at all above mentioned modles and a few more, Then built my own. Cost about $1400.00 but I have not burned a drop of Propane in 4 years,. You can set it up for pottable hot water too. If you have any other questions I would be glad to help. I learned a lot about the whole system including in floor heat and all that is needed.
 
   / Boiler plate?
  • Thread Starter
#3  
Back when I was building my outdoor wood boiler or stove.. I looked at all of the brands out there ( many more now ) I was lucky enough to do business with Wood Dr., Central Boiler, Heat-Mor and others. There was another inWisconsin selling Boiler Plate units stating that they were similar to what ships used to use. From what they told me, It was more ductile than regular carbon steel when used in a pressure situation. I looked around there were so many grades with so many ratings I just said the heck with it and used 7/16" mild steel. I used 7/16 because a friend with a roller had some to get rid of. Many of the stove companies use 1/8" MS or 304 or 409 SS. I'm not sure why you would need SS or Boiler Plate because most stoves are completely surrounded with water and rarely get hot enough to boil the water. That's why yhey last so long and mine has no pressure buildup at all. Use anti corrosion in the water and try to keep the stove as hot as possible to battle creosote. I looked at all above mentioned modles and a few more, Then built my own. Cost about $1400.00 but I have not burned a drop of Propane in 4 years,. You can set it up for pottable hot water too. If you have any other questions I would be glad to help. I learned a lot about the whole system including in floor heat and all that is needed.

Hey Yomax do you have any photos of your stove? I have a unit an Amish fellow built close to a central boiler design. I have been burning for 6 years now. I use central boiler additive in the water. I'm going to build my own replacement, no way I'm paying for a new unit. The lousy EPA requirements have added $3000 to the price of a new unit from him. I'm planning on rolling 3/8s for the outer course and maybe rolled 1/2" for the burn box.
 
   / Boiler plate? #4  
Metallurgical question for you guys. What is the difference between boiler plate and mild steel plate? I'm in the planning stages of building a wood fired boiler. Thanks!
The biggest difference is in the strength. ASTM 516 grade 60 or 65 is commonly used for pressure vessels in boiler steam drums up to 750F temps Common steel plate is ASTM A36 and is minimum 36KSI tensile where as 516- gr. 60 or gr.65 is 60-80KSI so it is twice as strong. For low pressure home hot water boilers, you could probably use A 36 grade as I doubt you would be making water more than 200F and max of 60 PSI . ASME SECTION 1 governs the fabrication of boilers and should be followed as a minimum design guide for construction of hot water or steam boilers. I would have to refer back to the code for what pressures the code applies to.
 
   / Boiler plate?
  • Thread Starter
#5  
Thanks Gary! The boiler system is open and doesn't build any pressure. The water is kept at 180 with a 10 degree drop before the draft door opens. Once the stove is fired and up to temp. They really don't run very hot.
 
   / Boiler plate? #6  
THE FOLLOWING ARE LIMITATION OF SECTION 1 POWER BOILER CODE AND MANDATORY USE. IF YOUR BOILER FALLS WITHIN THESE CONFINES YOU HAD BETTER BE FOLLOWING THE CODE ALTHOUGH IN ORDER TO DO SO, YOU HAVE TO HAVE A BOILER FABRICATION STAMP AND CERTIFICATION WHICH I AM SURE YOU WONT HAVE UNLESS YOU ARE A PRACTICING BOILER FABRICATION COMPANY.
ANYWAY BELOW ARE THE LIMITS THAT YOU CAN LEGALLY BUILD TO AND NOT BE CONSIDERED A BOILER BUILDER.
PG-2 SERVICE LIMITATIONS
PG-2.1 The rules of this Section are applicable to
the following services:
(a) boilers in which steam or other vapor is generated
at a pressure of more than 15 psig (103 kPa);
(b) high-temperature water boilers intended for operation
at pressures exceeding 160 psig (1100 kPa) and/or
temperatures exceeding 250ーF (121ーC).
PG-2.2 For services below those specified in PG-
2.1 it is intended that rules of Section IV apply;
however, boilers for such services may be constructed
and stamped in accordance with this Section provided
all applicable requirements are met.
PG-2.3 Coil-type hot water boilers where the water
can flash into steam when released directly to the
atmosphere through a manually operated nozzle may
be exempted from the rules of this Section provided
the following conditions are met.
(a) There is no drum, header, or other steam space.
(b) No steam is generated within the coil.
(c) Tubing outside diameter does not exceed 1 in.
(25 mm).
(d) Pipe size does not exceed NPS 3⁄4 (DN 20).
(e) Nominal water capacity does not exceed 6
gal. (23 l).
5
(f) Water temperature does not exceed 350ーF
(177ーC).
(g) Adequate safety relief valves and controls are
provided.
 
   / Boiler plate? #7  
Many of the stove companies use 1/8" MS or 304 or 409 SS. I'm not sure why you would need SS or Boiler Plate because most stoves are completely surrounded with water and rarely get hot enough to boil the water.

i can see using stainless for the firebox. i have spent a little time looking into building a gasifier for a hobby project and i remember reading that stainless was a good choice because the fumes from the burning wood are corrosive enough to prematurely deteriorate carbon steel.
 
   / Boiler plate? #8  
Hey Yomax do you have any photos of your stove? I have a unit an Amish fellow built close to a central boiler design. I have been burning for 6 years now. I use central boiler additive in the water. I'm going to build my own replacement, no way I'm paying for a new unit. The lousy EPA requirements have added $3000 to the price of a new unit from him. I'm planning on rolling 3/8s for the outer course and maybe rolled 1/2" for the burn box.

What would you like to see for pics? Plumbing in back or fire box and door on front? I also bought some insulated pipe that I slipped over my mild steel chimney and I suggest everyone do that. it goes a lot longer between cleanings due to the more even temps up the flue. I copied the pottable water coil idea for hot water and ball valve to fill, rear plumbing, door and size from a cheap stove called "Shaver". i modified the blower fan so it would close all the way when off, Fire brick in the door, Insulated chimney, and installed a moveable piece of steel to make the fan blower air come up further back. All made a huge difference. I.m heating a 3500 sq ft home and a 1200 sqft shop in floor heat. Fill 2-3 times daily on the coldest nights and burn 8-10 cordes yr. Im not far from Canada. I'll send you some pics when I can.
 
   / Boiler plate? #9  
i can see using stainless for the firebox. i have spent a little time looking into building a gasifier for a hobby project and i remember reading that stainless was a good choice because the fumes from the burning wood are corrosive enough to prematurely deteriorate carbon steel.

Stailess Steel especially 304 and 409 are great for corrosion. When I got a quote for the SS to build my stove It made it more cost effective to buy one already built. The A36 seems to be an ok choice as long as you don't let wet ashes lay around in the stove during the off season. Some of my friends built boilers 12 years ago and they running them now. I'm not sure how long they will last with MS but when it goes, I bet it's a mess. I think Central Boiler has a 10yr warranty and the fire box on most of their stoves is 5/32". They used to use 1/8" like most of the SS units.
 
   / Boiler plate?
  • Thread Starter
#10  
What would you like to see for pics? Plumbing in back or fire box and door on front? I also bought some insulated pipe that I slipped over my mild steel chimney and I suggest everyone do that. it goes a lot longer between cleanings due to the more even temps up the flue. I copied the pottable water coil idea for hot water and ball valve to fill, rear plumbing, door and size from a cheap stove called "Shaver". i modified the blower fan so it would close all the way when off, Fire brick in the door, Insulated chimney, and installed a moveable piece of steel to make the fan blower air come up further back. All made a huge difference. I.m heating a 3500 sq ft home and a 1200 sqft shop in floor heat. Fill 2-3 times daily on the coldest nights and burn 8-10 cordes yr. Im not far from Canada. I'll send you some pics when I can.

Any pics you might have would be good.
I talked to my relative that is a metallurgist for the filler division that is part of the Hobart Bros welding school. I thought it was Tri Mark not sure what it is now that miller is involved. Anyway , he told me to stick with carbon steel due to the fact that chlorides in heated water react to cheap stainless steel and actually will not last very long at all. He mentioned the thermal qualities on stainless makes it more unstable or something to that effect. He said the higher quality stainless ,that would work, would make a boiler unit priced way to high to build. Anyway that was the info I got from a guy with a degree.
 
 
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