Re: [MW:10333] grease using in gaskets between flanges

Dear Elshan,

The tightening of bolted flange can be done with the guidelines given in ASME - PCC--1 "Guidelines for Pressure boundary bolted flange assembly" which states about the numbering of bolts, toruque, usage of lubricants, alignment tolerances etc... 

in clause 6 & 7 it states that no lubricants shall be applied in flange faces. so no lubricant in flange face.

Refer the below extract from ASME PCC-1-2000

INSTALLATION OF GASKET

Place a new gasket in position after determining the absence of unacceptable imperfections or damage.

(a) Verify that theg asket complies with the dimensional (OD, ID, thickness) and material specifications.

(b) Position the gasket to be concentric with the flange ID, taking suitable measures to ensure that

it is adequately supported during the positioning process. No portion of the gasket should project into the flow path.

(c) Ensure that the gasket will remain in place during the joint assembly process; a very light dusting

of spray adhesive on the gasket (not the flange) may be used. Particular care should be taken to avoid

adhesive chemistry that is incompatible with the process fluid or could result in stress corrosion

cracking or pitting of the flange surfaces. Do not use tape strips radially across the gasket to hold it

in position. Do not use grease.

7 LUBRICATION OF "WORKING" SURFACES

With one exception, liberally coat all internal and external thread surfaces and nuvwasher faces with

appropriate lubricant; the exception is: lubricant is not to be applied to these "working" surfaces for

the initial tightening of new, coated bolrs/nuts [see Note (3) of Table lM/Table 11. The torque values 

for new, coated bolts/nuts shown in Table 1 M/Table 1 do not consider lubrication other than that provided

by the bolthut coating [see Note (2) of Table 1M/ Table 11. Do not apply lubricant to the gasket or

gasket-contact surfaces.

(a) Ensure that the lubricant is chemically compatible with the bolt/nut/washer materials and the process

fluid. Particular care should be taken to avoid lubricant chemistry that could result in stress corrosion

cracking.

(b) Ensure thathe lubricant is suitable for the expected service temperatureW.

Hope this will help you

Cheers

MM

On Wed, Mar 9, 2011 at 9:07 AM, Elshan Feyzullayev <elshan_f@hotmail.com> wrote:

Hi friends,

Is grease allowed to use in gasket surfaces between flanges bolted in the pipework?

regards,
Elshan.

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