Standard No.:	GB/T 43077.4-2023
English Name:	Connections for hydraulic fluid power—Ports and stud ends with general threads—Part 4: Hex plugs
Chinese Name:	液压传动连接 普通螺纹平油口和螺柱端 第4部分：六角螺塞
Chinese Classification:	J20    Hydraulic and pneumatic device
Professional Classification:	GB    National Standard
ICS Classification:	23.100.40 23.100.40    Piping and couplings 23.100.40
Source Content Issued by:	SAMR; SAC
Issued on:	2023-9-7
Implemented on:	2023-9-7
Status:	valid
Target Language:	English
File Format:	PDF
Word Count:	8500 words
Translation Price(USD):	255.0
Delivery:	via email in 1~3 business day

Connections for hydraulic fluid power - Ports and stud ends with general threads - Part 4: Hex plugs 1 Scope This document specifies dimensions and performance requirements for metric external hex and internal hex port plugs for use with ISO 9974-1 ports. Port plugs in accordance with this document can be used at working pressures up to 63 MPa (The permissible working pressure depends upon the plug end size, materials, design, working conditions, application, etc.). Conformance to the dimensional information in this document does not guarantee rated performance. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 3103.1- 2002 Tolerances for fasteners - Bolts, screws, studs and nuts (idt ISO 4759-1:2000) ISO 48-261) Rubber, vulcanized or thermoplastic - Determination of hardness- Part 2: Hardness between 10 IRHD and 100 IRHD ISO 261:1998 ISO general purpose metric screw threads - General plan Note: GB/T 193-2003 General purpose metric screw threads - General plan (ISO 261:1998, MOD) ISO 1629 Rubber and lattices - Nomenclature ISO 4042 Fasteners- Electroplated coatings ISO 5598 Fluid power systems and components - Vocabulary Note: GB/T 17446-2012 Fluid power systems and components - Vocabulary (ISO 5598:2008, IDT) ISO 9227 Corrosion tests in artificial atmospheres- Salt spray tests Note: GB/T 10125-2021 Corrosion tests in artificial atmospheres - Salt spray tests (ISO 9227 : 2017, MOD) ISO 9974-2 Connections for general use and fluid power - Ports and stud ends with ISO 261 threads with elastomeric or metal-to-metal sealing - Part 2 : Stud ends with elastomeric sealing (type E) ISO 10683 Fasteners- Non- electrolytically applied zinc flake coatings ISO 19879 Metallic tube connections for fluid power and general use- Test methods for hydraulic fluid power connections Note: GB/T 26143-2010 Connectors for hydraulic fluid power - Test methods (ISO 19879:2010, IDT) 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: - IEC Electropedia: available at http://www.electropedia.org/ - ISO Online browsing platform: available at http://www.iso.org/obp 3.1 plug stud end without fluid passage, used to contain hydraulic fluid 4 Dimensions 4.1 Plug dimensions External hex and internal hex plugs shall conform to the dimensions shown in Figure 1 and Figure 2 and given in Table 1 and Table 2, respectively. 4.2 Hex tolerances External hex tolerances across flats shall be in accordance with GB/T 3103.1-2002, product grade C. Minimum across corner dimensions are 1.092 times the nominal width across flats. The minimum side flat is 0.43 times the nominal width across flats. Unless otherwise specified or shown, hex corners shall be chamfered 10° to 30° to a diameter equal to the width across flats, with a tolerance of mm. Internal hex tolerances shall conform to GB/T 3103.1-2002, product grade A. 4.3 Screw threads The screw threads on the plug shall conform to ISO 261:1998, class 6g. 5 Requirements 5.1 Pressures and temperatures External hex and internal hex plugs conforming to this document shall be suitable for use at the working pressures given in Table 3 when used at temperatures from -40℃ to +120℃. For use at pressures and/or temperatures outside of this range, the manufacturer shall be consulted. Plugs conforming to this document may contain elastomeric seals. Unless otherwise specified, plugs are made and delivered with elastomeric seals for use within the specified working temperature range with petroleum-based hydraulic fluids. The use of these plugs and elastomeric seals with other hydraulic fluids can result in a reduced working temperature range or can render the plugs unsuitable for the application. Manufacturers may supply, upon request, plugs with elastomeric seals for use with hydraulic fluids other than petroleum-based hydraulic fluids that meet the specified working temperature range of the plugs. 5.2 Performance External hex and internal hex plugs conforming to this document shall meet the burst and impulse pressures given in Table 3, and shall be capable of withstanding a vacuum of 6.5 kPa absolute pressure when tested in accordance with Clause 7. 6 Elastomeric sealing Unless otherwise specified, for use at the pressure and temperature requirements in 5.1 and Table 3 and for testing, the elastomeric sealing shall - be made of NBR (nitrile) with a hardness of (90±5) IRHD, measured in accordance with ISO 48-2, and - conform to the relevant dimensions given in ISO 9974-2 (see Annex A). 7 Test methods CAUTION: The use of plugs conforming to this document with ports conforming to ISO 1179-1, ISO 6149-1 and ISO 11926-1 could lead to a hazardous situation. Port plug tests shall be conducted in accordance with ISO 19879 for burst, cyclic endurance (impulse) and vacuum tests. The torques given in Table 4 shall be used in testing. Test results shall be reported on the test data form in ISO 19879. 8 Designation of port plugs Port plugs shall be designated by an alphanumeric code to facilitate ordering. They shall be designated by the word “Plug”, then a space followed by ISO 9974-4 or GB/T 43077.4, then a dash, followed by the shape code PLEH for external hex plug or PLIH for internal hex plug, followed by sealing code S for plugs delivered with elastomeric sealing, then a dash, followed by the plug size. If desired, the code can be supplemented by a dash followed by the elastomeric sealing material code in accordance with ISO 1629, followed by a dash, followed by the plating code in accordance with ISO 4042 or ISO 10683. Example 1: Plug with an external hex for an ISO 9974-1 port size M12×1.5 is designated as follows Plug GB/T 43077.4-PLEH-M12 Example 2: Plug with an external hex for an ISO 9974-1 port size M12×1.5, ordered assembled with elastomeric sealing that conforms to the requirements of Clause 6 is designated as follows: Plug GB/T 43077.4-PLEHS-M12 Example 3: Plug with an internal hex for an ISO 9974-1 port size M12×1.5, ordered assembled with elastomeric sealing that conforms to the requirements of Clause 6 but made of FKM instead of NBR is designated as follows: Plug GB/T 43077.4-PLIHS-M12-FKM Example 4: Plug with an internal hex for an ISO 9974-1 port size M12×1.5, ordered assembled with elastomeric sealing that conforms to the requirements of Clause 6 and plated with galvanized zinc in accordance with ISO 4042 is designated as follows: Plug GB/T 43077.4-PLIHS-M12-A3C 9 Manufacture 9.1 Construction Plugs may be made from low carbon steel by forming or machined from bar stock, unless otherwise specified. 9.2 Workmanship Workmanship shall conform to the best commercial practice to produce high quality plugs. Plugs shall be free from visual contaminants, all hanging burrs, loose scale and slivers which can be dislodged in use, and any other defects that can affect the function of the parts. Unless otherwise specified, surface finish on all surfaces shall be Ra≤6.3 μm.