Help on O-Ring

Pick up the phone and talk to any of the following:

• The transformer manufacturer
• The transformer oil manufacturer
• Local O-ring suppliers
• Other users of the transformer
• Other users of the transformer oil
• Other users of O-rings

The undisclosed we should have a clue in form of part list and spare parts available for said transformer.

Then you need to know what material is suitable for your application. 110 deg C and transformer oil does not strike me as an easy material selection.

Last but not least you need to know what your O-ring groove dimensions are to make sure you fit the correct O-ring.

Usually O-ring provider have some good documentation about what is available and how to select them. I suggest you talk to a few of them.

Yes, you are looking for ASME B-16.5 (Table 5 and Annex E2) and ASME B16.20 (All) WP.

I am not aware of any "standard" but you have a selection of profiles available, round, square or quad for which the "slot" has to be designed( it really isn't a tight tolerance thing) for larger applications. Last one I did was for 36" diameter "manhole" opening and ended up using just neoprene rubber (60 durometer square - application was anearobic digestion tank). You will likely have to "fabricate" your own unless you have a large volume, but that is a relatively easy task if you can find the extrusion profile you select for the o-ring material. Just have to select the appropriate glue, most common is Loctite 404 which works on most natural and synthetic rubbers.

I take exception to your statement, ""fabricate" your own; but that is a relatively easy task".

Having "glued" my fingers to much o-ring stock in the past, a little instruction, and practice, is in order first. But, it can be done.

Instant Adhesive Application Case History: Working With O-Ring

Parker Hannifin Co. has published a very helpful guide to O-ring design. This guide includes flange design, grove dimensions, and O-ring material chemical compatibility. (google "Parker O-rings)

A "grove" dimension might apply to an orange or nut plantation.

Though this seems to be a big issue , You may get readily availoable answers if you contact the manufacture of transformer specific and any other similar size transformer. The shape and size in dia/ any shape can be obtained from the transformer body . Mostly I feel Neoprene rubber cylindrical O rings are used but I have coime across rectangular shaped rings as well. Better consult transformer manufacturer and / or reaqd the transformer manual. 110 deg is not an issue for O rings - the concern will be transformer oil at that temp. You maty get it coolly.

It is better to contact O ring manufacturers like Parker. I remember using some technical material from their products handbook for the same purpose as yours.

The cross section of your O-ring will depend somewhat on the amount of meat you have in your flange, the eccentricity you can tolerate, and the assembly force you require. Also involved will be the durometer (hardness) of the O-ring material you select. For example, you wouldn't use a .02" diameter O-ring on a flange that size if the machining tolerances were .032". Those diameters are sometimes used for watch seals. Once you deal with the eccentricity specifications, etc, you can begin to select the o-ring cross section. Delve into the requirements, use information in the manual to select the required compression, and the answers to your questions will get sorted out.

Hi All,

Thanks for the kind reply.

1. I have got a reference O ring size from a friend. 8mm dia O-ring has been suggested and groove dimension 6 depth and 11mm width. Grrove id = Flange id +10mm. All fine. but how the 8mm? why not 6mm or 10mm. O -ring supplier can supply any dia. But no one knows in my circle, the way to calculate the O-ring size.

Is it like we have to do R&D selecting various dia and do trial?

2. I have tried Parker. Not got any resonse. If you have any better contact, kindly share.

once again, thanks for all the replies..

-Regards,

Xmer

The Parker o-ring handbook can be downloaded from here for free: http://www.parker.com/portal/site/PARKER/menuitem.6c94058cc6466c6315731910237ad1ca/?vgnextoid=a141a35c7575e210VgnVCM10000048021dacRCRD&vgnextfmt=EN The phone number for the o-ring division is also shown on that web page. You can also use their inPhorm software to design your gland. Look up "inPhorm" and you'll find it.

When working in the trade and selecting o rings for repair our supplier provided a document dictating the dimensions. Very briefly a minimum 10% of the o ring should be above the surface to be sealed . All you had to do was match the o ring diameter to the o ring groove and measure the o ring diameter or take the dimension from the package if this information was provided then insert in the grove and with your calipers measure the distance above surface. This worked 100% for our group. There are o ring kits that you can purchase to make any o ring within reason I know we had some that were 15 feet in length. The kit comes with a tool and cutting device for precision square cutting of the end and an adhesive for joining the two ends. This procedure was also performed with the tool to ensure a very accurate alignment of the 90 degree ends. With the pressures you mention you should have success with the o ring kit.