Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Search results for query: *

  1. Compositepro

    There is Differential pressure (DP)

    The purpose of the flow indicators is, first to insure you have flow to keep the lines flushed, and second to be able to adjust each flow rate so the pressure drop in each sensing line is equal. With equal pressure drops, the dP reading is unaffected by the the pressure drops. There are also...
  2. Compositepro

    Insert bending test

    This is what hardpoints in sandwich structure are for. You can remove the honeycomb around the insert and replace with putty. Or you use rigid plates on one or both sides of the structure so there is little bending moment on the sandwich panel insert.
  3. Compositepro

    NPT vs NPSM thread for conduit nut

    Lock nuts are straight thread. As you note, what would be the point of a tapered thread here? It could only introduce problems in fit.
  4. Compositepro

    Three Link Force Calc

    This one is pretty easy since the one link is vertical. F output is simply the x component of the F input. You can then calculate the resulting torques. But it seems that torque is irrelevant to your problem.
  5. Compositepro

    Transverse Cracking in Carbon steel welds

    The transverse crack means that the weld is under significant axial stress (circumferential to the pipe). uniform spacing between the cracks is very typical where two materials are bonded together but they shrink or expand differently. The crack relives the stored shrinkage stress of the weld...
  6. Compositepro

    3ph Parallel Thyristor Rectifier Not Sharing Current

    That makes perfect sense. But that description sounds a little more complicated than saying to use inductive reactors in series with each scr rather than resistors. Reactors are commonly used to limit AC current where resistive losses are undesirable. My point is that the center tap is not an...
  7. Compositepro

    3ph Parallel Thyristor Rectifier Not Sharing Current

    As I recall from reading electronics literature 40 years ago, you will have the same problem with two diodes in parallel. The solution was to place resistors in series with each diode. As little as 0.1 Ohms may be sufficient. It does waste some energy as heat. Perhaps these days there is a more...
  8. Compositepro

    Post curing for LSR

    Silicone is a condensation cure polymer. It releases methanol or acetic acid during cure. The post cure is intended to complete the cure reaction, which releases these volatile materials. After the reaction is complete it still takes time for volatiles to diffuse to the surface and evaporate...
  9. Compositepro

    -94 F dew point dry air - issue with condensation

    I don't think that I have ever seen a compressed air distribution system that stayed dry consistently, including instrument air systems. Flow surges are almost impossible to prevent, and driers cannot deal with them. Most humidity sensors are very slow to respond and will not detect transients...
  10. Compositepro

    Vacuum pump sizing vs pipe conductance

    High-vacuum pumps are rated in volumetric flow at actual inlet conditions. They are basically positive displacement pumps that move a constant volume per unit time. Flow stays constant until you get to where the vapor pressure of the lubricant or off-gassing of the materials of the vacuum...
  11. Compositepro

    On-Site Wastewater Sewer Rock

    Angular particles are preferred where filtration is the goal. Round particles do reach full compaction much more easily and the flow channels through the bed are more uniform and thus less likely to plug. Any debris that makes it through the front face of the rock bed will more likely make it...
  12. Compositepro

    Influence of post-cure temperature on final properties

    There are differing scales of molecular mobility. In a fluid a molecule can move though it's entire container until it finds something with which to react. All monomers must have at least two reactive sites in order to form and extend polymer chains. Reactive sites on extending chains are...
  13. Compositepro

    Beam bending refresher

    No one seems to be considering the neutral axis of said beam. As the beam flexes the tension face lengthens and the compression face contracts. The final straight cord length of the tension face must become less than the distance between supports at the trigger point. A thin beam will trigger...
  14. Compositepro

    Help changing direction electric phase 1 motor

    Blue and yellow wires go to run winding.Red and black go to the start winding through the centrifugal switch and capacitors. To reverse the motor rotation, switch the blue and yellow wires relative to the black and red wires.
  15. Compositepro

    Influence of post-cure temperature on final properties

    Curing is a chemical reaction that stops when all the reactants are consumed, or when the molecules are no longer mobile enough to reach something with which to react. Two part systems are generally very reactive at low temperature, which is why they must be two part. Tg is the glass transition...
  16. Compositepro

    Pumping lake water

    The great things about a sand filter are that it will work well in removing fines as well as coarse debris, and backwashing is pretty much fully automated. It may be beneficial to recirculate water through the filter back into the lake so that the lake water does not become too dirty.
  17. Compositepro

    Turtle Shelling of Vessel Head

    It is an artifact of the "bump forming" process used to form it from flat plate. https://www.youtube.com/watch?v=rxIQsRBIqKo
  18. Compositepro

    Some scientists have an idea to bui

    For any given tensile strength and density of a material there is a maximum length of cable/rod that can be self-supported without breaking. Making it a larger diameter will not help in making it longer.
  19. Compositepro

    Unknown Item

    I assumed it was Velcro. It is commonly used in this way to aid holding something in place until the bolts can be placed and tightened.
  20. Compositepro

    Tourist submersible visiting the Titanic is missing Part 2

    The cross-sectional photos showing the fiber waves was not filament wound. You can see that unidirectional prepreg tape was used because the fiber layers are very uniform thickness with no visible tow structure. ElectroImpact makes fiber placement machines, which can use slit tape. But even...
Back
Top