Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Search results for query: *

  1. yogibear1

    Square Wet Wells - Good Idea or Bad Idea?

    Our system (in west central Florida) has over 650 wastewater pump stations. Most of the stations use submersible non-clog pumps passing a 3 inch sphere. The majority of wet wells in use are predominantly round precast concrete with an anti-corrosion liner or coating. Our Pump station Advisory...
  2. yogibear1

    Grinder Pump Question (Use Limitations)

    In our system (Hillsborough County, FL) each household = 1 EDU and is assumed to contribute 200 g.p.d. 25 homes would contribute 5,000 g.p.d or about 3.5 g.p.m. Assume a peak factor of 3 so the max flow would be only 10.4 g.p.m which is not very much for a grinder station. We cut off grinders...
  3. yogibear1

    Clean your Flange Faces?

    I believe I would wire brush the flange face to clean metal and then insert the spiral wound gasket (sounds like steam service?). It does not take much time to do this and you thus insure the best seating surface for the gasket. Painting the flange keeps it from getting rusted prior to your use...
  4. yogibear1

    Hydrostatic Testing on Fossil Fuel Boilers

    Safety valve settings do not follow the 1.5 multiplier that is used in hydro testing of pressure parts. This is partly due to the temperature difference between the two conditions and the relative strength of the materials at those temepratures. The low set safety valve on drum type boilers is...
  5. yogibear1

    PRVs in Water Booster Stations

    Actually what is needed is a PLC (programmable logic controller) which can handle the various logic scenarios for the system, not just the booster pumps, and take the appropriate action. VFD pumps and PLC's are a happy marriage and work well together. Since centrigual pumps heat up when the...
  6. yogibear1

    Boiler Insulation Materials

    I have seen calcium silicate insulation block double layered (mudded joints) over boiler tubes and high temperature steam leads. The block does not have the organic binders that rock wool or other blankets have, hence they do not break down over time. The organic binders are volatile and cook...
  7. yogibear1

    Basic precautions before re-starting Boiler

    Generally, roofs, that I am familiar with, have finned tubes which are overlain with a pourable lite weight refractory/insulation. Casing, which is generally flat steel plates can be seal welded over this. Is this what your roof looks like?
  8. yogibear1

    Basic precautions before re-starting Boiler

    Maypot: RMW had a real good post. It gave me a better picture of the type of unit. I am concerned about any pressure part damage since repairs to same were not metnioned in your post. Was the damage limited to casing, refractory, expansion joints and the like? What happened when the roof...
  9. yogibear1

    Basic precautions before re-starting Boiler

    NFPA 8502 is the Standard for the Prevention of Furnace Explosions and is availabe directly from NFPA.org. I think it is like $35.00. This may refer you to other codes too so don't stop too short. Your state/local codes often invoke NFPA or mimic their language- so you will have to do that...
  10. yogibear1

    Basic precautions before re-starting Boiler

    YES, it applies for any/every flame out condition, all fuel sources must be shut off and a purge initiated before (re)lite off. The burner logic controls are those controls which manage and safeguard the firing, and safety shut down of the flame envelope. This includes contacts (input) from the...
  11. yogibear1

    Basic precautions before re-starting Boiler

    Like I said above the unit MUST be purged to free it of any latent combustible gases. Your burner controls should have had this logic in it from day one; such is required by the NFPA, and state/local codes. Without such logic your insurance company will take a very dim view of paying any claims...
  12. yogibear1

    Basic precautions before re-starting Boiler

    Any time there is a flame out all fuel must be shut off and the unit purged to at least 30% of max air flow for a minimum of three to five minutes. Both FD and ID fans should be used. In the case where you had a "puff" the unit should be throughly examined to ascertain any damage which may may...
  13. yogibear1

    Pump Station with Gravity Connection

    ARV's are necessary and recommended at high points in any pipe line to release entrapped air (meaning any gas). If the air is not released, a pocket will form and prevent further pumpage. Indeed, sewage ARV's are bothersome, esp if the ports are small. Manual ARV's do work well as they are...
  14. yogibear1

    Pump Station with Gravity Connection

    Option 2 is very good and stainer has a good point about possibly directional drilling through the high point (to flatten out the profile). If you would drill, then use the best quality (HDPE) pipe possible since it will be deep and harder to maintain. You would not want to gravity the downhill...
  15. yogibear1

    Consequences of Pumping Out New Orleans

    DRC1 asked m.o.l.: "... where did all the Federal (flood control) money go?" I have heard (unsubstantiated) that much of it went to fund marinas and the gambling ships. If that is true, that makes it doubly sad and criminal.
  16. yogibear1

    ID Fan capacity

    Maypot: an item in a recent post merits looking at, i.e. the FD Fan dampers position. As an electrical engineer you can appreciate how load increases motor amperage- so check that aspect to see if your FD Fan is actually pumping any air. The FD Fan inlet is a lot easier to check than the ID...
  17. yogibear1

    TREVITESTS of safety valves

    I have used this method (didn't know it by that name) a number of times to successfully set safety valves. We had the safety valve rep (from Desser) do it. It is easier and quicker. It also avoids the actual pop off of a valve that may cause marring of the polished seating surfaces.
  18. yogibear1

    Steam Generator Lead-Lag control

    Is there help out there - well yes usually in the form of a controls consultant (controls vendors) (and they prefer to be paid for such work). As the client (I am one too) you would have to provide a lot of the stepping stone information which defines what you want to happen and when. It sounds...
  19. yogibear1

    ID Fan capacity

    Have you made sure that the ID Fan controls really are at 100% stroke when the inlet vanes are likewise at 100% fully open (this would have to de done when the unit is down to verify. It is possible that the linkage could have gotten bent out of shape or somethign has changed to short stroke the...
  20. yogibear1

    Flexible pipe connection

    Depends upon how felxible you want to be. Afterall there are hydraulic hoses rated for high pressures that work well on many types of construction machinery. I have also seen bellows expansion joints (metallic as well as as rubber like fabrics) on pump maniflolds. The Red Valve company makes...
Back
Top