BS ISO 5675:2021 pdf download – Agricultural tractors and machinery — General purpose quick-action hydraulic couplers
This document specifies the essential interface dimensions and the operating requirements for hydraulic couplers employed to transmit hydraulic power from agricultural tractors to agricultural machinery. It is applicable to couplers used in hydraulic lines other than those used for braking circuits.
NOTE All hydraulic couplers are intended to be connected and disconnected frequently to allow the transfer of machinery from one tractor to another without the use of tools or special devices.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.
ISO 7241:2014, Hydraulic fluid power — Dimensions and requirements of quick-action couplings
ISO 18869:2017, Hydraulic fluid power — Test methods for couplings actuated with or without tools
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at
— IEC Electropedia: available at
coupler female part
female part
part that has a cavity to receive the male part
coupler male part
male part
probe that fits and locks into the cavity of the female part
4 Requirements
4.1 General
The requirements of this document are applicable if conical style and ball style couplers are coupled together. Care should be taken to ensure that these requirements are fulfilled.
4.2 Dimensional requirements
The dimensions of the coupler male part shall be in accordance with ISO 7241:2014, Table 1 and Figure 1,“Series A”, for sizes 12,5 and 20. The coupler male part dimension shall also be in accordance with Figure 1 and Table 1 of this document. Additionally, a 15° angle shall be added in order to be compatible with dust protection devices.
Any coupler female part shall couple with any coupler male part when both conform to this document.
4.3.1 The coupler shall be in accordance with the operating requirements of ISO 7241:2014, “Series A” including the additional requirements for “Series A” in ISO 7241:2014, 6.2.
4.3.2 The pressure drop through the coupler shall not be greater than 0,35 MPa with a flow of 45 l/min for size 12,5 and 70 l/min for size 20. The pressure drop shall be measured in accordance with ISO 18869.
4.3.3 The fluid loss at an internal pressure of 0,1 MPa shall be in accordance with Table 2. A fluid loss test shall be conducted in accordance with ISO 18869. 4.3.4 The fluid loss when disconnecting with an internal pressure of 17,5 MPa shall be in accordance with Table 2.
4.3.5 The force required to fully open the valve in the coupler male part, when there is no internal pressure in the coupler male part, shall not exceed 45 N for size 12,5 and 70 N for size 20.
4.3.6 The coupling shall not check-off (closure of the valve) when oil flows in the male-to-female direction at flow rates less than 190 l/min for size 12,5 and less than 250 l/min for size 20. Fluid viscosity for this requirement shall be in accordance with ISO 18869:2017, 5.4 and 13.4.
5Location on tractor The coupler shall be mounted within the area described in Figure 2 for rear- and side-mounted couplers and Figure 3 for front-mounted couplers. Female couplers shall be used for rear- and front-mounted couplers. Female or male couplers may be used for side-mounted couplers. Tractors with three or less rear-mounted couplers shall place the rear-mounted couplers in area 2 described in Figure 2. Tractors with more than three rear-mounted couplers shall place three in area 2 and may place the additional rear-mounted couplers in area 4 described in Figure 2.BS ISO 5675 pdf download.