DANIELE MOLARO CONSULTING

Oilfield Consultant in Surface and Subsea Wellheads Equipment,Christmas Trees,Flow Control Equipment,Seals(Elastomerics & Metal-to-Metal)                  Contact me NEW E-mail: country45ve@yahoo.com

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3.1)       O-RINGS

 

O-Rings are the most popular way to make seal in wellhead designs, because they are simple, effective, low cost of production and quality control, and now with improvements in plastics materials, they come to be the best choice in wellheads business.

The principle that makes work an O-Ring seal is simple, they need a three point contact between the mating surface to the gland ,and need no other force extra applied, except the one that is supplied by the fluid's pressure to be retained.

Next images shows generic geometrical considerations and definitions for the O-ring Grooves of the Industrial Static Grooves Standard,  type, notice the surface finish, the radii, and the angles of the Grooves

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This is a typical industrial static groove standard for an O-ring, there are several critical parts: Gland Depth ; Groove Depth; Diametrical Clearance,Groove Width, and an included angle that is considered satisfactory between 0-5 deg. Surface finish are 63 RMS on the two upper sides, and the bottom contact wall is 32 RMS.

Technical considerations and calculations are not the purpose of this WEB page, but per your needs and specifications we can calculate it, and select the proper material for a specific needs and applications.

POINT OF ADVICE (!) WARNING:

Remember that for a good result and a successful seal application the seal design parameters has to be taken in close consideration, as well as a test in plant, or shop where by using hydrotest devices, the seal has to be tested, and graphic recorded, as well as a report of the seal's conditions after the test; which means a total inspection under an appropriate magnifier machine, making sure that seal has totally recover and: no marks, imperfections, cracks,scratches, etc, etc, will be detected, so that, makes the seal able to work again, and again. Take proper precautions, during test, remember pressures involved are HIGH PRESSURES and risks for the crew, and personnel in closer proximity are serious, and real, for their lives.

 

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     Picture of the left is a basic way to measure and purchase an O-Ring, the Standard Applicable is the AS-568-A it gives the basic dimensioning of the Standard O-Rings

 

 

 

This three pictures shows in sequence the basic way that an O-Ring Seals against a Surface is the principle of the three contact points, and the pressure of the fluid that makes possible the seal of it.

 

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Updated on:01/29/04Copyright @2003 Daniele Molaro Consulting

Note:This is only a brochure and is not intended to be used as a manufacturing's parts data information;our mission is announce our technical & engineering service and assist customers bringing them technical support, please contact us regarding this WEB site,or for assistance on site.