HG 20610-1997Spiral Wound Gaskets for Steel Tube Flanges (European System) (English PDF)

1 Scope

This standard specifies the type, dimension, technical requirements, labeling and marking of the spiral wound gaskets for steel pipe flanges (PN designated).

This standard is applicable to the spiral wound gaskets for steel pipe flanges specified in HG/T 20592 whose nominal pressure is PN16-PN160.

2 Normative References

The following standards contain provisions which, through reference in this text, constitute provisions of this national standard. For dated reference, subsequent amendments (excluding amending error in the text) to, or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to research whether the latest editions of these references are applied or not. For undated references, the latest edition of the normative document is applicable to this national standard.

"Hot-rolled Plain Carbon and Low Alloy Structural Steel Sheets and Strips" GB/T 912 "Cold Rolled Stainless Steel Plate Sheets and Strips" GB/T 3280 "Hot Rolled Stainless Steel Plate Sheets and Strips" GB/T 4237 "Cold-rolled Plain Carbon and Low Alloy Structural Steel Sheets and Strips" GB/T "Steel Pipe Flanges (PN designated)" HG/T 20592 "Specification for selection of Steel Pipe Flanges, Gaskets and Bolting (PN designated)" HG/T 20614 "Specification for Flexible Graphite Plates" TB/T 7758.2 "Compressed Asbestos Sheet" JC/T 69 "PTFE Unsintered Tape for Screw Sealing" QB/T 3628

3 General provisions

3.0.1 The type, code name, section form and applicable flange sealing surface type of gaskets shall comply with the provisions in Table 3.0.1.

Table 3.0.3 Service Temperature Scope of Gaskets

Metallic tape material Filling material Service temperature scope ( )°C Steel grade Standard Name Reference standard 0Cr18Ni9(304) GB/T 3280 Chrysotile tape a JC/T 69 -100~+300 00Cr19Ni10(304 L) Flexible graphite tape JB/T 7758.2 -200~+650b 0Cr17Ni12M02(316 PTFE tape QB/T 3628 -200~+200 00Cr17Ni14M02(316 L) Non-asbestos fiber tape -100~+250 0Cr18Ni10Ti(321) 0Cr18NillNb(347) 0Cr25Ni20(310) a The asbestos-contained materials shall be used according to the requirements of relevant law, and preventive measures must be adopted in order to prevent serious risk to heath.

b When it is used for oxidizing media, the maximum service temperature shall be 450 . °C c Different non-asbestos fiber tape materials have different service temperature scopes, which shall meet the provisions of the material producers.

2 The chemical compositions and mechanical properties of the filling materials shall meet the provisions of Table 3.0.4 and Table 3.0.3 of this standard. Recycled materials shall not be used for PTFE. The thickness of filling materials shall be stipulated by the producers so as to meet the gaskets' compression load characteristics specified in Article 5.0.4 of this standard.

Table 3.0.4 Main Performance of Filling Materials

Item Chrysotile and non-asbestos fiber Flexible graphite PTFE Tensile strength (transverse)(Mpa) >=2.0 >=2.0 Ignition loss (%) <=20 Content of chloride ion (X10-6) <=50 Melting point ( )°C 327±10

3 The inner ring materials shall possess the same or higher corrosion-resisting properties as metallic tape materials and the stainless steel materials shall meet the requirements of GB/T 3280 or GB/T 4237. Unless otherwise stated by the users, carbon steel may be adopted for centring rings. The carbon steel shall meet the requirements of GB/T 11253 or GB/T 912 and surface treatment such as spraying, electroplating shall be adopted.

4 If other metallic tapes and filling materials are adopted, it shall be indicated at ordering.

3.0.5 In addition to the basic type, inner rings shall be adopted for PN63/PN100/PN160 gaskets as well as gaskets which use PTFE as filling material.

Table 4.0.1-2 Dimension of Basic-type (A type) Gaskets or Inner Ring (B type) Gaskets for Tongue/Groove

Face and Female Face/Male Face Flanges (mm) Nominal dimension DN Inside diameter of inner ring D1 Winding part Inner ring thickness t Inside diameter D2 Outside diameter D3 Thickness 3.2 2.0 40 49 6l 75 80 90 106 120 100 116 129 149 125 143 155 175 200 222 239 259 250 276 292 312 300 328 343 363 350 381 395 421 400 430 447 473 450 47l 523 497 500 535 549 575 600 636 649 675

Figure 4.0.1 Dimension of Metallic Spirally Wound Gaskets

Type A

Type B

Type C

Type D

be less than four and there shall no welding defects such as overroasting or incomplete fusion.

3 The filling material on the upper and lower surface of the gaskets shall be smooth and be appropriately higher than the metallic tape (about 0.15mm±O.1mm).

4 The inner ring and centring ring shall be deburred.

6 Inspection

6.0.1 The material, dimension, appearance and manufacture of gaskets shall be compliant to the provisions of this standard.

6.0.2 Other inspection requirements may be determined through negotiating with the producers at ordering.

7 Labeling