Pipe Support Span 5

[coachk]

Anyone know of a good source for maximum spans between supports for various schedules of stainless alloy piping?

 

[LSThill]

HI coachk (Mechanical)

Do a advance search and your will fine many threads for pipe supportspand distance.

lst

 

[Hookem]

Try the old fashioned way and you will "learn" it better. Consider the pipe is supported at multiple, evenly spaced spans under uniform loading. Sound like a college structure problem now? It is. Moment is equal to .1071 wl^2. Stress = Mc/I. I is pi/64 * (OD4 - ID4). Should not exceed 5 to 6% of allowable bending stress, which is 2/3 of allowable. Compare to material allowable. Check deflection. Do not trap liquids between supports! Lastly, recognize that for all except small diameter pipes and large thin ones, plant pipe support standard spacings are usually smaller, e.g. conservative. Thus, all your trials and tribulations are for naught.

 

[MJCronin]

coachK,

I suggest that you solicit information from the stainless steel piping vendor... For schedule 40S piping, I would not hesitate to use the spans in ASME B31.1

Schedule 10S and 5S stainless steel piping have very short spans (as you might have guessed)

There are different spans for "water" versus air or gas service.

More span information can be found in the "Piping Handbook" ( 6th edition)

MJC

 

[MJCronin]

coachK,

try this document....lots of good info from the Army

http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-1-4008/c-4.pdf

MJC

"There comes a time in the affairs of man when he must take the bull by the tail and face the situation." W.C. Fields

 

[coachk]

Thanks for the quick response....particularly to MJCronin - the table was just what I needed.

 

[raja011]

Thanks MJCronin - the table was just what I needed, but I would like to know the Span for larger diameter of pipes (As the table shows only upto Dia.300mm) and moreover since we are using in our present project ranging from Dia.1800mm (SS316L) to Dia.200mm (SS 316L)

 

[DLANDISSR]

Coachk:
Grinnell has a table in their "Piping Design and Engineering" book which gives pipe spans for pipe filled with water. The limiting factors are 1500PSI combined bending and sheer stress and max .1"deflection.

size/ft are as followsince you have spans up to 12&quot
12"/23'; 14"/25'; 16"/27'; 18"/28'; 21"/30'; 24"/32'; 26"/33'; 28"/33' 30"/34'; 36"/35'

This is for straight runs with no concentrated loads. If there are changes in direction the spans should be less than 3/4 of the values shown in the table. Concentrated loads should be supported indivudually without regard for the spans table.

Spans for other conditions, such as, more dense fluid or gas can be calculated from the formulas given by Hookem and from the criteria stated above.

If horizontal movement is present the hanger rod should be long enough so the angle of the rod will not deviate from vertical more than 4DEg. It it does uplift will occur and put additional forces on the hanger. If the movement will cause a deviation of the hanger rod more than 4Deg rollers should be employed so the pipe can roll through the hanger without displacing it.

If vertical movement is present spring hangers should be employed so the support will move with the pipe. If the support does not move upward with the pipe, the pipe will lift off the support. This will cause excessive deflection of the pipe and additional forces imposed on adjacent hangers.

If the pipe moves down excessive forces will be transfered to the non-moving hanger and the pipe will lift off adjacent hangers.

The transfer of forces when the pipe moves will also cause excessive stress in the pipe itself. This may cause the hangers or pipe itself to fail.

 

[beercia]

What is the recommended piping deflection to assure adequate drainage of the piping? Is there a practical rule of thumb?

Carlos

 

[KevinNZ]

We design spans for large diameter pipes by considering the design of the pipe at each support like a pressure vessel support.

the pipe has stress from pressure and gross bending. Then there are local stresses at the slipper/shoe.

We use appendix G from BS5500 to calculate the local stresses.

We consider the effects of shoes with and without re-pads.

This way you can use some quite long spans.

Cheers
Kevin

 

[soleimani]

HI,MJCRONIN
UNFORTUNATLY CONNECTING TO

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FOR ME IS
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