Hellow,everybody

Anyone here know about the difference of coil spring and disc spring?Most spring vendor provide the product made of coil spring,but I found some vendors in China still use disc spring.I don't know which one is better,which one is more suitable in chemical plant?Can somebody throw some light on this topic? Thanks in advanced!

A disc spring? Are we talking about something like you would find in a wind-up watch?

When I hear the term 'disc spring', Belleville Washers come to mind.

http://www.bellevillesprings.com/

Sometimes, counter-weight type constant support is used instead of spring coil but I never either heard or experienced that disc spring was used in lieu of coil spring hanger support in oil&gas and petrochemical industry.

Generally disc spring is employed in piping stress engineering for the purpose of two;
First, to improve flange leakage and valve gland seal - Used with bolted bonnet of valves and flange joint. It can maintain the proper bolting pressure against long-term consolidation of gland packing material and bonnet gasket, and flange gasket in nuclear power and toxic chemical plants.
Second case is ; Typical hold down supports for pulsation system like reciprocating compressor/pump piping to mitigate vibration.

Can I see the vendor Catalog or website in China ? I am very interested in….

Ah yes, the belleville washer. I must confess, I have a hard time seeing how you build those into a practical piping spring support that would have much travel capability.

Thanks for all the response.The spring I mentioned made from disc springs is some disc springs stacked in series,then put the stacked column into spring house.The vendor said this spring can provide a shoter length for installation,and they are popular used in some power plants and chemical plants.
Dear sun wee,the vendor's website is in Chinese,and the information is very limited.I think it make no sense.
It's my first time to meet this type spring,I am not sure it's really as better as what vendor said.Any concerns and suggestions will be appreciated!

Rockey,

Please post the link to this vendor's website. I want to take a look at this, and I have someone who can read Chinese.

http://www.hd-ps.com

I hope it can be useful for your understanding.Thanks.......

http://www.dfdj.com; http://www.jsyzxh.com
There are still two other company provide disc spring.

Bellevilles are extremely non-linear and hardly suitable as a pipe supporting element but hey who cares about the maximum variabilty versus industry standards!

More rework headed my way$$$$$$

Sir,

Moreover, disc springs are usually stiff springs, but can be made soft by using multiple springs in series in stacks, each facing opposite of the above ones.
But, the real positive point may be cost & ease of manufacturing. We can't rule out the possibility of rugged, cheap springs made of disc springs before hearing from vendors & users.
So far as non-linearity is concerned, we can linearize near the zone of application & use linear spring model, isn't it ? Moreover, 25% variability limit may be unnecessary, when we use the spring stiffness in analysis & the governing state code does not insist so.

Chinese could be creative because they could not read English & study industry standards to limit their imagination! Moreover, eastern thinking encourages multiple views, evidences / contradictory evidences instead of rigid recommendation as the basis for any decision.

I have seen extremely complicated pulverized coal power plants of 25 MW size with 5/6 feed water heaters, which may look funny, but can create a lot of operators with excellent experience for running bigger sized plants of similar complexity.

Our biggest drawback is in following the past blindly. If our past generations were like us, perhaps they could not make such great progress!

regards,
sam


please see below:
http://www.pipingtech.com/news/arc_pw_2003/engps2003_04.htm

for similar sway brace application with 715 kg/mm stiffness

Sam,

I have used Bellevilles in the past for High Load low deflection usage, and have designed the stacks accordingly similiar to these sway braces... (Interestingly enough one of the best texts for designing them I have is in German, auf Deutsch if you will)

But 25% max variability for a spring support is based on something or another and I doubt that adventures significantly above that figure will produce credible results.

Cars, trucks, and other things use coil springs for the same reason that make them nice for supports... quasi-linear behaviour and a lot of deflection criteria.

Meanwhile I look forward to the redesign contract.

Sir,

I have used disc springs for washers in flanges & reviewed the vendor calculations based on German specifications. Before using these washers, the SS flange/ AS bolt flange was leaking during start-up & not leaking in opr cond.

regards,

sam

yes indeed Sam the bellevilles, stiff though they may be are much more flexible the bolted joint itself, an excellent use for them!!!

See (An excellent resource and wonderful author) http://www.amazon.com/gp/product/0824792971/sr=8-1/qid=1145026090/ref=pd_bbs_1/002-5266171-6212834?%5Fencoding=UTF8

However these uses involve far less deflection than a spring can support typical used on a pipe support.

Thank You, Sir for your kind mentoring.

Most of the time we can't afford the books you mention to refer. In India this is the irony of being born in not-so-rich high caste! Generations after generation the merit - be it academic or creative- is taking a backseat in this democracy!

As you all are there to help the people who seek, we remain. May Lord bless our teachers like you!

regards,
sam

The March 2006 issue of Pumps & Systems magazine has an article on using Belleville springs - but for live loading of valve packing. Still interesting. It's written by Fran Pugliese of Solon Manufacturing. The article and others are posted on their web site - wwwsolonmfg.com.

The article states how they can be stacked with different orientations (concave up or concave down) to adjust stiffness. There's a good list of references too.

I learned of these a few years ago. A CAESAR II user mentioned using these disk springs under pumps to "soften" the vertical thermal loads on their nozzles. I don't see how these could be used as pipe supports.

Thanks very much,everybody here.My colleague provided me some photos at one chemical plant,where the disc springs really used as pipe supports.And this plant have worked move than 6 years.As of now,there is no problem occured here.

Regarding the use as piping supports see these links:


http://www.idrosapiens.it/media/07/07.html

http://esss-na.com/case_20NDPipelines.html

http://www.freepatentsonline.com/8033367.pdf

Dears,

For disc spring pipe support, I have come across the follwing supplier link recently.

http://info.pipingtech.com/disc-spring-support/

Where there is a space & load combination limitation or corrisive environment limitation forbids use of spring support, such a design can be useful.

regards,
sam

Belleville washers or disc springs are convex discs supported at the outer periphery by one force and an opposing force on the centre of the disk. This unique characteristic of the Belleville washers allows them to be used in multiple configurations to support the structure being built with the desired load.

Coil springs create energy when the coils are pushed together. The elastic material allows it to return to original form once the load has been lifted. These are used in common applications such as mattresses, toys, and shock absorber systems.

The difference:
Both have the same function but the main difference is their load versus deflection characteristics.

Disc spring designed to withstand very high loads with a small amount of deflection on the other hand coil springs can only accommodate lighter loads and much higher deflection.

Here is the supplier link where we usually get them https://itafasteners.com/products-washers-belleville.php

Piping Technology has come out with a new line of product where a very short travel spring support is required. Low and behold, it is stacked Belleville Washers. See it in their new catalogue.

Dave, I am the CAESAR II user who mentioned the use of stacked Belleville washers when I was a participant in a CII seminar in Houston. This was well before Piping Technology had come out with their new product line mentioned above.

Regards to all.

Pat LaPointe P. Eng.