ISO 7483:1991 pdf download – Dimensions of gaskets for use with flanges to lSO 7005.
3.2Gasket designs according to flangefacing
3.2.1For type A (flat face) or type B(ralsedface) flange facings
The gaskets shall have a centring ring.A PN15O,PN 260 and PN 420gaskels and aill gaskets contain-ing polytetranluoroethylene (PTFE)filler materialshall have an inner ring.
The use of an inner ring is recommended for PN 20,PN 25.PN 40.PN 50 and PN 110 gaskots.Inner rings maybe fitted also to gaskets for use with PN 10 and PN TGflanges.
8 The purchasor should spocify in the order and/or en-quiry i an innor ring is roquirod for PN 10,PN 16.PN 20,PN 25.PN 40,PN 50 or PN 110 gaskets.
9 Figure7 shows two types of gaskets for use withtypo A or type B flange facings.
3.2.2For type c/D(tongue and groove) flangefaclngs
The sealing elementonly shall be used (seenigure 8).
3.2.3For type E/F (spigot and recess) flangefaclngs
The sealing element only or the sealing elementwith inner ring shall be used (see fligure sy –
NOTE 10 The purehaser should specify in the enquiryand/or order if an inner ring is required.
The centring ring shall be marked with the followinginformation:
a)the number of this lnternational standard. i.e. lSO 7483:
b) the manufacturer’s name or trade-mark;
c) the nomina size,l.e. DN followed by the appropriate number;
the nominal pressure,i.e. PN followed by the appropriale number;
the manufacturer’s symbols for the melal winding and filler materiai.
3.4 Dimensions
Gaskets for type A and type B flange facings shallhave the dimensions specified in lable appro-priate. and the overal thickness(including niiler)shall be in accordance with figure 6 or shall not ex-ceed 5.2 mm for sizes up to and including DN 1 000,For sizes above DN 10Oo, the overall thickness shallnot exceed 7,5 mm.
NOTE Thicknesses given in ligureBare preferreddimensions for sizes up to aind including DN 1000.
Gaskets for type c/D and E/F flange facings shallhave dimensions suitable for flange facings showninn figure 10 and given in able apprapriale.Gaskels having an inner ring for lype E/F fangefacings [ see figure 9b)]shall have an inner ringminimum internal diameter as specified in fable appropriate.