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Recent content by pesy

  1. pesy

    Convert IVEX .BRD File to more useful format

    Is there some way to convert the file to ORCAD, or something else more common? I contracted the CB design on a new product by a EE (I'm an ME). The EE used IVEX. So now I have a .BRD file generated in an IVEX program. I'm having the board assembled by a 3rd party, and I want them to be able...
  2. pesy

    More Questions on 201 Stainless vs. 304 Stainless

    Does anyone have any data on the corrosion resistance of 201 compared to 304 or 316 in dilute sulfuric acid or dilute carbonic acid? The application is for use in the flue of a condensing boiler. Pesy
  3. pesy

    Copper Fin-Tubes Heater & Minimum Water Flow

    I have run some calculations and I don't think the fin tip temperatures in this product get much above 1500F (melting at 2000), having calculated a gas-side-convection coefficient of about 21 BTU/hr-ft-F (using estaimtes since I haven't found any textbook equations for heat transfer in...
  4. pesy

    Copper -Fin Tube Heaters & Minimum Flow

    Good point about the condensing. Yes, it would be for gas/propane/oil. I'm actually considering the new design to be a condensing product by using alternate materials so the condensate will not corrode anything. I'm trying to find out the mechanism of failure on the copper-fin products so...
  5. pesy

    Copper -Fin Tube Heaters & Minimum Flow

    In a perfect system, the temperature sensor / switch would detect how much heat is going into the water and either modulate the input or shut the unit off before the water boiled. Scaling and/or fin-melting would not be prevented if those are the failure modes (or maybe there's another I...
  6. pesy

    Copper Fin-Tubes Heater & Minimum Water Flow

    I am extremely well versed in heat transfer, thank you. "heat transfer" is not an issue. Heat transfer occurs to whatever degree the thermal resistance, heat transfer coefficient, and LMTD allow. In a perfect system, the temperature sensor / switch would detect how much heat is going into the...
  7. pesy

    Copper -Fin Tube Heaters & Minimum Flow

    Water is the medium. Is poor heat transfer the only problem, or can damage occur to the unit? Typically the warranty of such a product is voided with insufficient flow, so it must be something worse than merely reduced heat transfer.
  8. pesy

    Copper Fin-Tubes Heater & Minimum Water Flow

    Why do copper-fin water heaters require minimum flows? What would happen if it was provided 40F inlet water, and set to 200F outlet water? a) Is it an issue of scale build-up? b) Is it an issue of melting fins? What is the reason for (a) or (b)--Does it occur only because there is unequal...
  9. pesy

    Copper -Fin Tube Heaters & Minimum Flow

    Why do copper fin-tube water heaters require minimum flows? What would happen if it was provided 40F inlet water, and set to 200F outlet water? a) Is it an issue of scale build-up? b) Is it an issue of melting fins? What is the reason for (a) or (b)--Does it occur only because there is...
  10. pesy

    CO2 Monitors

    Why do copper-fin water heaters require minimum flows? What would happen if it was provided 40F inlet water, and set to 200F outlet water? a) Is it an issue of scale build-up? b) Is it an issue of melting fins? What is the reason for (a) or (b)--Does it occur only because there is unequal...
  11. pesy

    slope of ramp in a parking garage

    How steep can one make a ramp in a parking garage? My frame of reference is what is common in multi-level garages in big cities or at airports.
  12. pesy

    pneumatic pressure adder

    Does anyone manufacture a pneumatic pressure adder? I have 2 pressures that I want to add together to provide a pressure signal to a Siemens SKP20 SSOV/regulator. One signal is about 4"WC (natural gas) and the other varies from -0.5" to -2" WC (air). I want to add the two together and provide...
  13. pesy

    Bimetallic vent dampers

    Where can I get a low ambient compensation kit?
  14. pesy

    Bimetallic vent dampers

    Power is available--however a control system to determine how much power to deliver to the device is not available. A self-controlling device would be fine.

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