IEC 61518 pdf download – Mating dimensions between differential pressure (type) measuring instruments and flanged-on shut-off devices up to 413 bar (41,3 MPa)
1 scope
This International Standard is applicable to differential pressure (type) measuring instruments(instrument) with a shut-off device (manifold) directly bolted on to them.
This standard specifies mating dimensions and tolerances, threads,bolts, and gaskets for amaximum allowable working pressure of 41,3 MPa (413 bar) at 38 °C.
This standard does not apply to assemblies that provide additional sealing elements (adapters)between the instrument and the manifold.
Where the possibility exists, shut-off devices shall be mounted on either side of the instrument,and all connections shall then meet this standard.
Elements, such as flanged coupling joints, may apply this standard or parts thereof to increasestandardization at the discretion of the supplier and the end-user.
This standard is only valid for instrument and manifold flanges manufactured from a metallicmaterial with yield strength equal to, or larger than, 190 N/mm2.
2Normative references
The following normative documents contain provisions which，through reference in this text,constitute provisions of this InternationalStandard. For dated references，subsequentamendments to,or revisions of,any of these publications do not apply.However，parties toagreements based on this International Standard are encouraged to investigate the possibilityof applying the most recent editions of the normative documents indicated below.For undatedreferences, the latest edition of the normative document referred to applies. Members of lECand lS0 maintain registers of currently valid International Standards.
ISO 48:1994，Rubber，vulcanized or thermoplastic – Determination of hardness(hardnessbetween 10 IRHD and 100IRHD)
lso 898-1:1999，Mechanical properties of fasteners made of carbon steel and alloy steel -Part 1: Bolts，screws and studs
ISO 1629:1995, Rubber and latices – Nomenclature
ISO 3506 (all parts), Mechanical properties of corrosion-resistant stainless-steel fasteners
ISO 3601-1:1988, Fluid systems – Sealing devices – O-rings – Part 1: Inside diameters,cross-sections,tolerances and size identification code
Iso 3601-3:1987,Fluid systems – Sealing devices – O-rings – Part 3: Quality acceptancecriteria
ASME B18.3.1M:1986(R1993),Screws, socket head cap (metric series)
ASME B18.2.1:1996,square and Hex Bolts and Screws inch Series
ASTM A193:1999，Specification for alloy steel and stainless steel bolting materials for high-temperature service
ASTM A449:1993,Specification for quenched and tempered steel bolts and studs
3Dimensions
Dimensions in figures and tables are in millimetres,except where stated otherwise.
Leak-tight connection between the differential (type) measuring instrument and the flangedinstrument manifold depends upon the conformance to the dimensions and the tolerances.
3.1Connection dimensions at the differential pressure (type) instrument
See figure 1.
3.2connection dimensions at the shut-off deviceTwo designs for the manifold facings are recommended:- Type A: design with an extended spigot (see figure 2);- Type B: design without an extended spigot (see figure 3).
NOTE Type B design may also be suitable for differential pressure (type) transmitters， where the connectingdimensions are not in accordance with this standard. The user is responsible for ensuring compatibility for trans-mitters with different dimensions.
3.3Seal rings
The specifications for the flat ring are those of tables 1 and 2.
The O-rings are in accordance with the lso standards quoted.
Materials and temperature limits for the flat rings and the O-ring are for reference only. lt is theresponsibility of the user to ensure compatibility between the selected gasket ring material andthe process requirements, such as pressure, temperature,and chemical compatibility.
IEC 61518 pdf download – Mating dimensions between differential pressure (type) measuring instruments and flanged-on shut-off devices up to 413 bar (41,3 MPa)
