This standard (HG 20592~20635-97) is formulated by revising the primary standard HGJ 44~76-91 as well as HG 20527-92 and HG 20529-92 by reference to ISO 7005-1 (1992), ANSI B16.5 and DIN standards. The new standard after revision includes the international current European and American systems and forms a set of standard in allusion to pipe flange, gasket and bolting which has intact contents and clear system and is suited for Chinese conditions and gears to the international conventions. The new standard will improve the current situations of standards in this field such as disordered system, poor matchability and obsolete contents.
Thereinto, HG 20592~20614-97 belongs to European system and is formulated by revising and combining HGJ 44~76-91, HG 20527-92, HG 20529-92 and HG 5001~5028-58. Compared with the former standard, the newly revised standard has the following changes:
1. Applicable to outside diameter of steel tube, extending to international current series (A) and domestic following series (B) from domestic following series;
2. Supplemented threaded flange and integral flange and cancelled flanging ring loose flange;
3. Adjusted the pressure class range of slip-on hubbed flange and slip-on-welding flange
Slip-on hubbed flange PN0.6~4.0MPa DN≤600mm
Slip-on-welding flange PN0.25~0.6MPa DN≤2000mm
PN1.0~2.5MPa DN≤600mm
4. Revised sealing face dimensions and flange technical conditions;
5. Increased material varieties such as cast steel material and low temperature steel forging;
6. The pressure-temperature table of stainless steel was revised on the basis of 1% yield strength;
7. Adapting to two sets of steel tube outside diameter series, and adjusted and supplemented the gasket dimension;
8. Supplemented rubber, synthetic rubber and non-asbestos rubber pressboards as well as modified (filled) polytetrafluoroethylene flat washer material; revised the asbestos rubber gasket standard as standard for flat washer made of various nonmetallic materials;
9. Increased bolting length matching for various flange joints;
10. Marked the pipe flanges with the standard No. in HG 20592.
HG 20615~20635-97 belongs to American system and its compilation principles are as follows:
1. Took ANSI B16.5 and B16.47 as reference standard for the part of pipe flange; the SI system of parameters and dimensions is based on ISO 7005-1 (1992) and ISO 7483 (1991);
2. Adopted the marking pressure class of ISO 7005-1 (1992) (cancelling Class 75 and Class 400) so that the pressure classes of pipe flanges in European system and American system will not be mixed up.
PN(MPa) Class
2.0 150
5.0 300
11.0 600
15.0 900
26.0 1,500
42.0 2,500
3. Restricted the applicable PN-DN range of threaded flange and loose flange:
Threaded flange PN2.0~5.0MPa DN15~150mm
Loose flange PN2.0~11.0MPa DN15~600mm
4. Incorporated welding neck-collar (ANSI B16.9 and MSS SP43) into loose flange standard;
5. Incorporated Series B large-diameter flange of in ANSI B16.47 (API 605), and cancelled Series A large-diameter flange;
6. Increased DN 550mm (PN 2.0~11.0MPa);
7. Two sealing face types, i.e., small male and female face and small tongue and groove face, were not listed;
8. Restricted the flange types applicable to ring-joint face (integral flange, welding neck flange, socket welding flange and flange cover);
9. Compiled the pressure-temperature table according to ISO 7005-1 (1992) and ANSI B16.5 (1988); the applicable pressures of 20# steel and 15CrMo were properly adjusted due to the difference of mechanical property at normal temperatures, and the corresponding material classification of 16Mn is Class 1.3;
10. Compiled gasket standard on the basis of ANSI B16.20 (1993) and B16.21 (1992);
11. Increased the table of bolting length matching various flange joints;
12. Determined standard system and standard constitution of the part of American system by reference to HG 20592~20614-97 (European system).
This standard was proposed and organized for preparation by the Equipment design technology center station of Ministry of Chemical Industry and the chemical process piping design technique center of Ministry of Chemical Industry.
Chief drafters of this standard: Ying Daoyan, Yu Jun and He Anliang.
PROFESSIONAL STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
中华人民共和国行业标准
HG 20601-97
Steel Pipe Flanges Cover (European System)
钢制管法兰、垫片、紧固件（欧洲体系）
1 Subject Content and Application Scope
This standard specifies types, dimensions, technical requirements and relevant application requirements of steel pipe flange covers (European system).
This standard is applicable to steel pipe flange covers with nominal pressure PN 0.25 MPa (2.5bar) ~25.0 MPa (250bar).
2 Normative References
HG 20592 Steel Pipe Flanges Types and Parameters (European System)
HG 20603 Specification for Steel Pipe Flanges (European System)
HG 20604 Steel Pipe Flanges Pressure-temperature Class (European System)
HG 20613 Fasteners Used for Steel Pipe Flanges (European System)
HG 20614 Selection of Steel Pipe Flanges, Gaskets and Bolting (European System)
3 Flange Cover Sealing Face Type or/and Application Scope
3.0.1 Flange cover has five sealing face types, i.e., raised face (RF), male and female face (MFM), tongue and groove face (TG), flat face (FF) and ring-joint face (RJ), and its dimension and selection shall be according to those specified in Chapter 6 and Chapter 8 of HG 20592.
The sealing face dimensions f1 and f2 of flange cover with raised face, male and female face as well as tongue and groove face are included in flange thickness C.
The platform height E of flange cover with ring joint face flange is not included in the flange thickness C.
3.0.2 The pressure and diameter range applicable to flange cover with various sealing face types shall be according to those specified in Table 3.0.2.
Table 3.0.2 applicable range (mm)
Sealing face type Nominal pressure PN, MPa (bar)
0.25
(2.5) 0.6
(6) 1.0
(10) 1.6
(16) 2.5
(25) 4.0
(40) 6.3
(63) 10.0
(100) 16.0
(160) 25.0
(250)
Raised face (RF) DNl0~2,000 DN10~1,200 DN10~600 DN10~400 DN10~300
Male and female face (MFM) - DN10~600 DN10~400 DN10~300 -
Tongue and groove face (TG) - DN10~600 DN10~400 DN10~300 -
Flat face (FF) DN10~600 DN10~1200 -
Ring-joint face (RJ) - DN15~400 DN15~300
4 Flange Cover Dimension
The dimension of flange cover shall comply with those specified in Figure 4-1 and Tables 4-1~10.
