flange facings
flange facings
(OP)
Can any body tell me the difference between the different flange finish 63 aarh, 125 aarh and 250 aarh . Also please advise for for what applications/ operational conditions to specify 63 / 125 /250 finish. (Academically I would like to know 63 , 125 , 250 refers to the depth of cut or the no of serrations on flange face or any thing else )
RE: flange facings
250 microinches can be acheived with power saws. 125 can be acheived with milling, and 63 can be done with laser cutting. Less than 63 requires grinding or honing.
Smoother is always better but there is a tradeoff in cost, of course.
RE: flange facings
I wasn't certain, so I looked at my copy of ASME B46.1-1985, SURFACE TEXTURE. The closest I see to this is the description of Roughness Average Ra, AA or CLA, depending on what country, "Arithmetic Average Roughness".
Since we're doing this for Acedemia's sake,
the approximation formula is Ra=y1+y2+y3...+yN / N
Where
Ra = arithmetic average deviation from the center line (of the surface)
y = ordinate of the curve of the profile ( absolute value )
N = number of increments
Eric Johnson
RE: flange facings
For nonmetallic gasket sheet, it can be compressed to the flange serration. This type of gasket is suitable for FF (flat face) flange which is 250-500 AARH.
For spiral wound gasket, it always use with RF (raised face) flange which is 125-250 AARH.
For metallic gasket and metal jacketed gasket, very smooth flange surface (63 AARH) is suitable for this application.
RE: flange facings
RE: flange facings
RE: flange facings
RE: flange facings