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  1. kyong

    Diesel Leak rate through a buried pipe

    Antwerp, rho is density. BigInch, your vena contracta factor 0.62 is more specific than my 10~50% friction loss. One thing I reconsider is that resitence by liquid can be bigger than I originally thought. If ratio of compactness of the soil to leakage flow rate is high, it can be prettry...
  2. kyong

    Diesel Leak rate through a buried pipe

    Simple physics can apply to calculate maximum theoretical flow. dP=1/2 * rho * v^2 v= (2*dP / rho)^2 Q=A*v=9 gpm In a short time of beginning of leakage, soil adhered to the pipe will be broken. It may be less than 1 second or so. Negligible. Once it happens, soil resistence will be zero and...
  3. kyong

    Integrally reinforced nozzle

    If all parts are full penetration welded, it should be regarded as integrally reinforced. Non-integrally reinforced nozzle means a nozzle that has reinforcement mass which is not full penetration weld.
  4. kyong

    Restraints for static stress of a cylinder

    cbrn, I think I missed one thing in my discription of the problem. The cylinder is hollow cylinder. The cylinder is receiving internal pressure/thermal gradient and so on. The two end faces of the cylinder are intended to remain perpendicular to axis which is straight. That is my desired...
  5. kyong

    Restraints for static stress of a cylinder

    If I want make both end faces of a cylinder keep perpendicular to the axis while allowing free movement of one end face in axial direction, what would be the best way? I tried a few settings, getting not very satisfactory result. One of the settings I used is : 1) make a reference axis. 2) set...
  6. kyong

    Thermal stratification on pressure vessels

    LesT, Please pay attention on this fact : If cooling or heating rate is high, temperature gradients will bigger and amplitude of cycle bigger, which means fatigue will come sooner. If you can evaluate this temperature gradient in terms of heating or cooling rate, you will be able to set an...
  7. kyong

    How good is Brownell & Young's Method to Design Base plates

    Can anybody make a comment for me on how good is Brownell & Young's method to design steel base plates for vertical vessels/towers?
  8. kyong

    base plate thickness and bolt preload

    boo1, your data about bolt preload range is valueable to me. Thank you.
  9. kyong

    base plate thickness and bolt preload

    As KarlIT and J1D mentioned, preload is necessary to keep gripping. If the load is alternating like wind on tower, without preload, the joint become loose or gap between base plate and foundation will form. In that regard, I think the preload should be near design bolt load. On the other hand...
  10. kyong

    base plate thickness and bolt preload

    Hi, Lutfi, Thank you. Your comment is valuable to me. Can you tell a little more why you don't need to consider bolt preload even though you think preload affects?
  11. kyong

    base plate thickness and bolt preload

    I am checking base plate thickness calculations produced by a software. I see that bolt preload is affecting the calculated thickness quite much. It seems to me right. However, formulas in my aonthor reference book(Pressure Vessel handbook by Eugene F. Megyesy) doesn't show anywhere the term...
  12. kyong

    How would g(gravitaional acceleration) affect vibration?

    Thank you, guys. Your inputs are definitely helpful to me. kyong
  13. kyong

    How would g(gravitaional acceleration) affect vibration?

    This is not a practical problem. Rather, it is a problem to understand vibration in general sense a little more. To calculate fundamental period of vibration, I often use Rayleigh approximation which is T = 2* pi * [(summation(W*y^2)/(g*summation(W*y))]^0.5 where W=weight of each...
  14. kyong

    VIII-1: Can you use the higher stress values for alloy tubesheets?

    The reason why not to use higher allowable stress for flange design is to minimize flange leak due to deformation. If deformation of a tubesheet is not to be causing critical problems, higher stress value may be used. Actually I use higher value for tubesheet design. When tube sheet has extended...
  15. kyong

    Pipe Freezing

    TBP, It's difficult for me to understand how come the flow rate should depend on pipe length. Oh, I see. The water cools down along the pipe! Then water temperature 40 deg F should mean start temperature, I think. And required flow rate should directly depend on start temperture. This is an...
  16. kyong

    Superheated steam in heat exchangers

    I like rmw's first posting. When superheated steam(at leat a few hundred degree higher than saturation temperature) is given to you any way, you can utilize it by specially designed desuperheating zone. Desuperheating zone of feed water heater has many baffles to increase velocity of the steam...
  17. kyong

    Steam Quality

    Many heat exchanger designs for plants assume steam quality of 100%. This is quite rational because in most cases, saturated steam is the best for heat transfer purpose and therefore plants will intend to operate steam system so that saturation steam can go into each equipment. Actually steam...
  18. kyong

    How do I find Contact Resistance values?

    Reverse of contact resistence for a symplified model will be hc = 1/Lg * (Ac/A * 2*ka*kb/(ka+kb) + Av/A*kf) Lg=thickness of void thickness Ac=contact area Av=void area A=Ac+Av, total area ka, kb=conductivity of material of each side kf=conductivity of fluid(air or something else) filled in...
  19. kyong

    Overlay weld on tubesheet of a heat exchanger

    Thank you, prex and deanc. I agree with you guys. I think I have to give up trying to justify not following part UCL. kyong
  20. kyong

    LMTD manipulation

    Roach, If you want to fix flow rates of both sides, to reduce hot side temperature is only way. And as 25362 wrote, U will decrease a little. So LMTD should be a little more than 31. 25362 is saying around 34. On the other hand, any way, reducing hot side flow rate will also decrease cold side...
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