Pipe hanger calculations 2

[LJS]

Does anyone have sample calculations for the design of simple adjustable swivel ring pipe hangers using all-thread rod? Ideally, the format would satisfy NFPA 13 requirements.
Thanks,
LJS

 

[JohnBreen]

Hi LJS,

You may have a misconception of how easy this will be.

If you are going to design supports for a piping system, the design and the hardware that you use must comply with Codes and Standards. By themselves, consensus Codes and Standards are voluntary. However when these Codes and Standards are made mandatory by a local building Code, they have the "force of law". So, you should find out what mandatory building Standard your local jurisdiction mandates and build your system accordingly.

You are going to discover that there is a succession of Codes and Standards that reference each other to totally cover the construction. The piping Code will mandate that the hanger hardware comply with he requirements of (Manufacturer's Standardization Society) MSS SP-58 and the design should be in accordance with MSS-SP69. Not a bad thing because all this standard pipe support hardware is "load rated" (each and every rod, clamp, turnbuckle and threaded fastener is load rated by the manufacturer). Once you determine what the load is at each support location, it is just a matter of picking the hardware (with the appropriate load rating) from a catalog of a creditable manufacturer. Go to the Anvil – Grinnell web site at:

http://www.anvilint.com/

Click on pipe hanger catalog and download the pdf file. Then open the catalog and the type of hanger that you need for your application. If you have much temperature variation you may need help to pick spring hangers.

You must then follow the path of the load from your pipe support, all the way down to the ground to be sure that every element in that path (beams, joists, columns, etc.) is capable of safely (within safe limits including a factor of safety) transferring that load to the ground.

You can look at the Piping Handbook by M. Nayyar for approximate methods of calculating the distribution of loadings over the support system, or you can use a computer program to do it. It is non-trivial and you have to pay close attention to the methodology.

Some Codes and/or Standards (and some pipe support catalogs) include hanger spacing tables to tell you the maximum acceptable spans between hangers but be aware that these tables do not include consideration of concentrated weights like valves and valve operators. There are books and design manuals that you can consult.

I hope I have not been too fundamental for you but I did the best I could with your request without assuming too much.

God luck and best regards, John.

 

[stanier]

Suggest you download the Licad program available from

http://www.lisga.com.

This is really elegant and simple to use.

 

[JohnBreen]

Oooops,

Stanier really meant look for Licat at this address:

http://www.lisega.com/

Regards, John.