HG/T 20627-2009 (HG/T20627-2009)

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HG/T 20627-2009: PDF in English (HGT 20627-2009)
HG/T 20627-2009
Chemical Industry Standard
of the People's Republic of China
HG
Replacing HG 20627-1997, HG 20629-1997
Non-metallic Flat Gaskets for Use with Steel Pipe Flanges
(Class Designated)
(Class)系列
ISSUED ON. FEBRUARY 5, 2009
IMPLEMENTED ON. JULY 1, 2009
Issued by. Ministry of Industry and Information Technology of the People’s
Republic of China
Contents
1. Scope ... 3 
2. Normative references ... 3 
3. Material and working conditions ... 3 
4. Gasket type and dimension ... 6 
5. Technical requirements ... 14 
6. Marking illustration ... 15 
1. Scope
This standard specifies the type, dimension and technical requirements of non-metallic
flat gaskets (with insertion or without insertion) for use with steel pipe flanges.
This standard is applicable to the non-metallic flat gaskets for use with steel pipe flanges
whose nominal pressures from C1assl50 (PN20)-C1ass600 (PN110) are specified in HG/T
20615 and HG/T 20623.
Note. As for the use of the gaskets in which contain the material of asbestos, it shall meet the requirements of the relevant
laws and regulations. If the aforesaid gaskets are used, the protective measures shall be adopted to prevent man from damaging.
2. Normative references
The following provisions contained in the following standards are turned into the
provisions of this national standard by being referred in this national standard. For date
reference, the subsequent amendments to (excluding amending error in the text) or revisions
of, any of these publications do not apply. And parties to agreements based on this standard
are encouraged to investigate the possibility of applying the most recent editions of the
standards indicated below. For undated references, its latest edition referred to applies.
GB/T 528 "Rubber, Vulcamized or Thermoplastic--Determination of Tensile Stress-strain
Properties"
GB/T 539 "Oil-resisting compressed asbestos fiber jointing"
GB/T 3280 "Cold rolled stainless steel plate sheet and strip"
GB/T 3985 "Compressed asbestos fiber jointing"
HG/T 20615 "Steel Pipe Flange (Class Designated)"
HG/T 20623 "Major Diameter Steel Pipe Flange (Class Designated)"
HG/T 20635 "Specification for Selection of Steel Pipe Flange, Gaskets and Bolting
(Class designated)"
JB/T 6613 "The classification code and sign of flexible graphite sheets/strip"
JB/T 6628 "Reinforced flexible graphite (sheets) gaskets"
JB/T 7758.2 "Specifications of flexible graphite sheets"
QB/T 3625-1999 "PTFE sheet"
3. Material and working conditions
3.0.1 Material category
The materials of the non-metallic flat gaskets for use with steel pipe flanges contain.
1 Natural rubber, neoprene, styrene-butadiene rubber, chemigum, ethylene propylene
diene copolymer and viton;
manufacturer's brand shall be indicated. The applicable pressure, temperature and maximum
(P×T) value of the gaskets shall be determined according to the working condition.
3.0.3 Working Conditions
Working conditions of the nonmetallic flat gaskets shall meet the requirements of Table
3.0.3.
Table 3.0.3 Working Conditions of Non-metallic Flat Gaskets
Classification Name Standard Code name
Application Range
Maximum
(p×T)
(MPa×℃)
Nominal
pressureC1ass
Working
temperature
(℃)
Rubber
Natural rubber
NR 150 -50-+80 60
Neoprene CR 150 -20-+100 60
Chemigum NBR 150 -20- +110 60
Styrene-butadiene rubber SBR 150 -20-+90 60
Ethylene propylene diene
copolymer EPDM 150 -30-+140 90
Viton FKM 150 -20-+200 90
Asbestos rubber
Paronite GB/T 3985
XB350
150 -40-+300 650 XB450
Oil-resisting paronite GB/T 539 NY400
Non asbestos
fiber rubber
Non asbestos
fiber rubber
pressing-a
Inorganic
fiber
b NAS ≤300
-40-+290-d
Organic
fiber -40-+200
-d
Teflon
PTFE sheet QB/T 3625 PTFE
-50-+100
Expansion PTFE sheet/strip
b.c
ePTFE
-200-+200-d
Stuffing modified PTFE sheet RPTFE ≤300
Flexible graphite
sheets
Reinforced flexible graphite
sheet-e
JB/T 6628
JB/T 7758.2 RSB ≤600
-240-+650(used
in oxidative
medium. -240 -
+450)
High-temperature
mica
High-temperature mica
composite plate ≤600 -196-+900
Note. 1 Reinforced flexible graphite sheet is compounded by stainless steel impacting or punch drying plate and expanded
graphite particle. And stainless steel impacting or punch drying plate plays a role in enhancement.
Table 4.0.2-1 The Dimension Ff-type Gasket for Use with Flat Face Flange Class150 (PN20) (mm)
Nominal dimension Inside
diameter of
the gasketa Dl
Outside
diameter of
the gasket
D2
Number of
bolt hole
n (piece)
Diameter of
bolt hole L
Diameter of
bolt-hole
center circle
Gasket
thicknessb T DN NPS
15 21 22 89 4 16 60.3
1.5c
20 411 27 98 4 16 69.9
25 1 34 108 4 16 79.4
32 411 43 117 4 16 88.9
40 211 49 127 4 16 98.4
50 2 6l 152 4 18 120.7
65 212 77 178 4 18 139.7
80 3 89 191 4 18 152.4
100 4 115 229 8 18 190.5
125 5 141 254 8 22 215.9
150 6 169 279 8 22 241.3
200 8 220 343 8 22 298.5
250 10 273 406 12 26 362.0
300 12 324 483 12 26 431.8
350 14 356 533 12 30 476.3
3d
400 16 407 597 16 30 539.8
450 18 458 635 16 33 577.9
500 20 508 699 20 33 635.0
600 24 610 813 20 36 749.3
a D1 is the maximum inside diameter of the gasket. The other diameters of the internal diameters gasket may be determined
by the user, but it shall be indicated at the order time.
b Gasket thickness T listed in the table is recommended gasket thickness.
c Rubber blanket thickness is larger than or equal to 1.5mm.
d Rubber blanket thickness is larger than or equal to 3mm.
(Continued) (mm)
Nominal dimension Inside
diameter of
the gasketa
Dl
Outside diameter of the gasket D2
Nominal pressure C1ass
Gasket
thicknessb
Wrapping
width
b DN NPS
125 5 140 196.0 215.0 240.0
1.5
150 6 169 221.5 250.0 265.0
200 8 220 278.5 306.0 319.0
250 10 273 338.0 360.5 399.0
300 12 324 408.0 421.0 456
350 14 356 449.5 484.5 491
400 16 407 513.0 538.5 564.0
450 18 458 548.0 595.5 612
500 20 508 605.0 653.0 682.0
600 24 610 716.5 774.0 790.0
a D1 is the maximum inside diameter of the gasket. The other diameters of the gasket may be determined by the user, but it
shall be indicated at the order time.
b Gasket thickness T listed in the table is recommended gasket thickness.
Table 4.0.2-4 RF- and RF-E-type Gasket Dimension for Use with the Raised Face Flange (HG/T 20623 B
Designated) Whose Nominal Diameter is Larger than DN600 (mm)
Nominal dimension Inside
diameter of
the gasketa
D1
Outside diameter of the gasket D2 Gasket
thicknessb
Wrapping
width
b DN NPS
Nominal pressure Class
650 26 660 724.5 770.0 764.5
700 28 711 775.5 824.0 818.5
750 30 762 826.0 885.0 879.0
800 32 813 880.0 939.0 932.0
850 34 864 933.5 993.0 998.0
900 36 914 985.5 1047.0 1049.0
950 38 965 1043.0 1098.0
1000 40 1016 1093.5 1148.5
1050 42 1067 1144.5 1199.5
1100 44 1118 1195.5 1250.5
1150 46 1168 1254.0 1317.0
1200 48 1219 1305.0 1368.0
1250 50 1270 1356.0 1419.0
1300 52 1321 1406.5 1469.5
1350 54 1372 1462.0 1530.0
1400 56 1422 1513.0 1595.0
1450 58 1473 1578.5 1657.0
1500 60 1524 1629.0 1708.0
a D1 is the maximum inside diameter of the gasket. The other diameters of the gasket may be determined by the user, but it
shall be indicated at the order time.
b Gasket thickness T listed in the table is recommended gasket thickness.
Table 4.0.2-6 TG-type Gasket Dimension for Use with Tongue and Groove Face Flange
Class300 (PN50)-Class600 (PN110) (mm)
Nominal
dimension
Inside
diameter of
the gasket
D1
Outside
diameter of
the gasket D2
Gasket
thicknessa
Nominal
dimension Inside diameter of
the gasket D1
Outside
diameter of
the gasket D2
Gasket
thicknessa
T DN NPS DN NPS
15 21 25.5 35.0
1.5a
150 6 190.5 216.0
1.5a
20 43 33.5 43.0 200 8 238.0 270.0.
25 1 38.0 51.0 250 10 286.0 324.0
32 411 47.5 64.0 300 12 343.0 381.0
40 211 54.0 73.0 350 14 374.5 413.0
3a
50 2 73.0 92.0 400 16 425.5 470.0
65 212 85.5 105.0 450 18 489.0 533.0
80 3 108.0 127.0 500 20 533.5 584.0
100 4 132.0 157.0 600 24 641.5 692.0
125 5 160.5 186.0
a Gasket thickness T listed in the table is recommended gasket thickness.
5. Technical requirements
5.0.1 Dimension tolerance of FF-type and RF-type gaskets shall meet the requirements of
Table 5.0.1.
5.0.2 Dimension tolerance of MFM-type and TG-type gaskets shall meet the requirements of
Table 5.0.2.
Table 5.0.1 Dimension Tolerance of FF-type and RF-type Gaskets (mm)
Nominal dimension ≤DN300 (NPSl2) ≥DN350 (NPSl4)
Inside diameterD1 ±1.5 ±3.0
Outside diameter D2
-1.5
-3.0
Diameter K of FF-type bolt-hole center
circle ±1.5
Adjacent bolt hole center distance ±0.75
Table 5.0.2 Dimension Tolerance of MFM-type and TG-type Gaskets (mm)
Inside diameter D1 Outside diameter D2
+1.0
-1.0
5.0.3 Thickness tolerance of the 1.5mm-thickness gasket is±0.1mm; and thickness tolerance
of the gasket whose thickness is larger than or equal to 3mm is±0.20mm. The thickness
difference of the same gasket shall not be larger than 0.20mm.
5.0.4 Gasket shall be flat and without buckling deformation. there shall not be slag inclusion,
crack, bubble, extr...
......
 
(Above excerpt was released on 2017-03-06, modified on 2021-06-07, translated/reviewed by: Wayne Zheng et al.)
Source: https://www.chinesestandard.net/PDF.aspx/HGT20627-2009