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Recent content by FishScreener

  1. FishScreener

    Vehicle impact attenuation speed.

    Thanks. The existing signs, were designed and the bases installed by the CCC work crews in the mid to late, 1930's. They are considered, historical, and a real pain to modify. Plus, in the 80 or so years they have been there, none of them have been hit from the roadway. There have been a...
  2. FishScreener

    Vehicle impact attenuation speed.

    I'm kind of stuck between the rock and a hard place. I'm trying to design to current standards, which require the breakaway bases. The Rangers want to keep the historic Forest Service Bases, which are raised pads made mortared rock. And admittedly they are attractive. They are also...
  3. FishScreener

    Vehicle impact attenuation speed.

    I tried a google search for "fhwa vehicle attenuation", and didn't get anything that made sense. I was hoping someone who does enough geometric design, or traffic engineering might know offhand which standards apply so I could narrow down the search.
  4. FishScreener

    Vehicle impact attenuation speed.

    I work for the Forest Service, and am working on developing plans to install new signage on approximately 45-miles of unpaved Forest road. The speed limit is posted at 35-mph. There are about ten of the old style Forest Facility signs, that are installed in raised mortared rock platforms...
  5. FishScreener

    Suitability of Materials for heater in septic vault vent

    Here's my reasoning: If I assume that the solar panels are 75% efficient, then it should take approximately 16-sf of solar panels to equal the solar gain of the 12-sf of black body absorber that the original pipe is. Since, the solar panels are direct connected to the resistive heat...
  6. FishScreener

    Vault toilet off gasing

    What gases would be expected to off gas from a vault toilet. For those who may not know: A vault toilet consists of a reinforced concrete vault, with an epoxy lining, with a toilet seat assembly bolted to the top slab of vault. Typically a precast concrete building is placed on top for...
  7. FishScreener

    Suitability of Materials for heater in septic vault vent

    The combustible gas is methane, which is lighter than air. And the vault is vented. Thus, the methane concentration can't get to the levels they are explosive or combustible. However, I'm not sure how corrosive methane is. I do know that ammonia, and the hydrogen sulfide, are corrosive. I...
  8. FishScreener

    Suitability of Materials for heater in septic vault vent

    There will be no thermostat. The Solar panel will be direct connected to the resistive element, and the element sized to limit the total heat gain, based on the maximum output of the solar panel. We are trying to mimic the thermal cycle, which would occur with an exposed semi-gloss black...
  9. FishScreener

    Suitability of Materials for heater in septic vault vent

    I guess I should have given some more information on what Vault Toilets are: Vault toilets are used in areas with out water/sewer and usually without power. The vault is a waterproof concrete vault with an epoxy lining, which holds, the waste. The toilet is installed on the concrete top...
  10. FishScreener

    Suitability of Materials for heater in septic vault vent

    I'm working on developing an electric heater to be inserted into a 10-inch id polyethylene pipe, that is the vent for the vault on a vault toilet. The vault is normally vented by the convection generated in the black pipe as it heats in the sun. Which warms the air and causes air to flow in...
  11. FishScreener

    Coating for metal stilling basin lining.

    I'm working with a Design Consultant, to solve a problem with a low head dam in a wilderness area. He is proposing to reline a stilling basin, at the diversion to a micro-hydro power plant with welded mild steel. (Long ugly story of multiple, un-engineered band-aid fixes over the last hundred...
  12. FishScreener

    Solubility of metals as a function of pH

    Not sure if this is the right group to ask, but I think you will know either the answer or who to ask: One of the hydrologists working on a mine tailings environmental study just walked in and asked if I had a table that shows the solubility of various metals as a function of the pH. I found...
  13. FishScreener

    NFPA 10 travel distance

    Thanks, guys. I am pretty sure that the code has been 75-foot travel distance forever. But, I still don't know for sure. So, I will probably pay for the two new cabinets out of my budget, rather than argue with the Landlord. We have had a few rough times this year, so I can do it as a good...
  14. FishScreener

    NFPA 10 travel distance

    The current and last several versions of NFPA 10, require a maximum travel distance of 75-feet to fire extinguishers in commercial builings. Does anyone have a copy of the code in force in 1992, that can tell me what it was then? I have a leased building that has two hall ways with fire...
  15. FishScreener

    Inlet Screen Diffuser

    Big Inch, you seem to miss the point and have trivialized the whole thing. The screen sizing is easy, and so for that matter is the diffuser manifold design. But, I work with and for biologists, for whom the math is intimidating, and who want to rebuild whatever they saw in a catalog. Not...

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