1 Scope
This standard specifies the dimensions for bolted flanges, rotatable flanges and clamped flanges of low, medium and high vacuum equipments used in vacuum technology. This standard is applicable to flanges connecting low, medium and high vacuum equipments.
The dimensions ensure interchangeability between bolted,
rotatable and clamped flanges.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. Howevere, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.
GB/T 321-2005 Series of preferred numbers (ISO 3:1973, IDT)
GB/T 1800.1-1997 Limits and fits—Bases—Part 1: Terminology (neq ISO 286-1:1988)
GB/T 1800.2-1998 Limits and fits—Bases—Part 2: Basic rules of tolerances, deviations and fits (eqv ISO 286-1:1988)
GB/T 1800.3-1998 Limits and fits—Bases—Part 3: Numerical values tables of standard tolerances and fundamental deviations (eqv ISO 286-1:1988)
GB/T 1800.4-1999 Limits and fits—Bases—Part 4: Tables of standard tolerance grades and limit deviations for holes and shafts (eqv ISO 286-2:1988)
GB/T 3452.1-2005 Fluid power systems—O-rings—Part 1: Inside diameters, cross-sections, tolerances and size identification code (ISO 3601-1:2002, MOD)
GB/T 4982-2003 Vacuum technology—Quick release couplings—Dimensions—Part 1: Clamped type (ISO 2861-1:1974, IDT)
GB/T 5277-1985 Fasteners—Clearance holes for bolts and screws (eqv ISO 273:1979)
GB/T 5286-2001 Plain washers for bolts, screws and nuts—General plan (ISO 887:2000, IDT)
GB/T 17395-1998 Dimensions, shapes, masses and tolerances of seamless steel tubes (neq ISO 1127:1992, ISO 4200:1991, ISO 5252:1991)
3 Dimensions
3.1 General
3.1.1 The dimensions of the flanges or collars shall conform to those specified in Tables 1, 2 and 3 and shown in Figures 2, 3 and 4. These dimensions are for finished products and do not include allowance for machining. Flanges or collars with nominal bores of 10 to 40 inclusive, given in Tables 1 and 2, accept the corresponding quick-release couplings specified in GB/T 4982-2003.
3.1.2 Under general conditions, the selected materials shall be Q 235A or No.20 steel, which requires to be non-magnetic steel or austenitic stainless steel for corrosive medium. Other materials shall meet the requirements of Annex A for linear sealing loads and welding of flanges.
3.2 Nominal bore
3.2.1 The tables provide a series of values of nominal bores intended to identify the flanges or collars.
3.2.2 These values follow the progression of the R1O series of preferred numbers specified in GB/T 321-2005.
3.3 Diameter of bolt holes, C
The values for the diameter of bolt holes, C, are derived from the bolt diameters, d, in accordance with medium series of GB/T 5277-1985.
3.4 Mating face
3.4.1 The mating face of the flange is the area in the form of a ring, the surface finish and the flatness of which make the sealing of the joint possible.
3.4.2 The minimum mating face is defined by diameter D, D2 and D3 in the tables.
3.5 Outside diameter of bolted and rotatable flanges, D1
The dimensions given for the outside diameter are compatible with the requirement that the bolt washers (GB/T 5286-2001) shall not project beyond the outer circumference of the flange.
3.6 Number, n, and position of bolt holes
The bolt holes shall be arranged at the position shown in Figure 1, where angle α is the function of the number of bolt holes. The linear sealing loads tabulated in Annex A for a given bolt stress are derived from the values of the number of bolt holes, n.
Foreword i
1 Scope
2 Normative references
3 Dimensions
Annex A (Normative) Linear sealing loads
Annex B (Informative) Types of sealing grooves and flange connection
Annex C (Normative) Bores for vacuum flanges and required outside tube diameters
Annex D (Informative) Comparison of clause numbers between standard and ISO 1609:1986
Annex E (Informative) Technical deviations and relevant justification
