I used to size them using condensation energy :
Variables
Total weight of piping system (including valves etc)
Specific heat capacity of steel
Required warm-up rate
Energy generated by condensation of steam
Saftey factor to cover for heat loss through insualtion etc.
By using the above you can...
The Max pressure rise can be calculated by multiplying the density of the fluid by speed of sound of fluid by velocity of fluid. You can then estimate the forces by pressure X area
This value will only be achieved if the valve closure times are less than the time it takes for a sound wave to...
Anybody got a spreadsheet/program for quick sizing of pipe insulation?
I have an old basic program, but it does not cover below zero C temps and only has 5 common insulants and 5 claddings.
I still see new examples on large diameter (2 to 5 meter)
pipes on cooling water systems.
Prehaps the material saving of using very thin walled pipes
with triforms on tees and ring stiffeners on straight pipes
justifies the cost and difficulties.
It may be worth contacting a company that designs...
Tri-forms, as I know them, are a set of 3 rib stiffeners.
1 going around the underside of the main, and the other 2
wrapping around the top of the Main and Branch Crotch. Where they meet (either side of the tee in the saddle region) all 3 are connected to each other using a solid bars.
Calcs we...
We have been involved in solving vibrating piping systems, due to fluid dynamic problems.
Where the the problem is not too severe, and there is a very flexible piping system, then the best solution is to restrain the pipe. There are several types of support from plain boxing in with steel and u...
BS5500 appendix G, is a good paper in detailing the local loading (stresses), in thin walled vessels. I would think the empirical formulaes could be applied to any size of pipe, its the d/t ratio which is important.
A chap named Zick also did alot of work in this area.
They both indicate that...
I would to do a risk assessment
Calculate the probability of failure (High medium or Low)
Assess the concequencies of failure, Fatalities through to no consequence
High risk with fatalities - keep away
Low risk with no connsequenies - do it
To assess the risk of failure ---
A hydrotest is...
I'm sorry I don't.
I have done it myself in the past on High pressure high temp steam pipes operating in the creep range.
Basic rules to follow are
1) Introduce a cold spring/pull in one direction only. It is almost impossible to put it in, in more than one direction at site.
2) Don't use more...
There is no design limit to the bend radius - just the capabilty of bending the pipe without flattening and reducing the wall thickness below the minimum wall thickness. Rippling of the intrados should also be avoided.
Small bore pipes (NB2" and below) have usually enough extra wall...
Cold Springing, reduces the max thermal loads (and stresses) in a system, by introducing a predetermined stress in the pipe when it is cold. Its main purpose is to reduce the peak loading on connecting equipment.
However it does not effect the overall stress range, and therefore it cannot be...
Max span depends on 2 main criteria:
1) Stress - B31.1 suggests limiting max bending moment stress to 2100 psi
2) Deflection at mid span. If this is excessesive you will get condensate collection. Again B31.1 suggests a limit of 0.1", but I would guess the actual limit could be higher...
Sway braces are in effect a very soft snubber, and the trick is to get maximum effect for the dynamic cases without
overloading the thermal case.
Your right, its not easy to model sway braces, and much depends on the particular manufacturer as to how to model them.
In most cases they are...
The condensate flow would be a secondary issue as long as the pipes have a correct fall when the ship is level. The condensate will eventually find its way to the collection points. You may require bigger drain pockets, as it may arrive in spurts rather than smoothly.
As far as the actual...
