Hydraulic Quick Couplers Common Industry Terms
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- Issue Time
- May 21,2025
Summary
EHHYDRAULIC-Common industry terms used for hydraulic quick couplers are explained in this article. If you have inquiries about hydraulic quick couplers, please get in touch with us at sales@ehhydraulics.com.
Brinelling
Locking ball contact marks on metal surfaces under high impulse loads.
Burst Pressure
The pressure threshold at which a coupling structurally fails and can no longer maintain system integrity.
Dis/Connect Force
The force required to engage or disengage couplings in a pressure-neutral state, measured in Newtons (N) or pounds-force (lbf).
Connect Torque
The rotational force (in N·m or lb·ft) needed to securely connect couplings in a pressure-neutral state.
Coupled Condition
Male coupling half connected with the female coupling half.
Disconnect Torque
The rotational force (in N·m or lb·ft) needed to securely disconnect couplings in a pressure-neutral state.
Interchangeability
The compatibility of male/female halves to connect with other manufacturers' couplings.
ISO Size
The size indicated by the ISO standard (International Organization for Standardization) related to the interchangeability of the couplings.
ISO Norm
The norms used as reference for the test method are two:
ISO 7241-2 issued in 1986 then canceled and replaced in 2017 by the new ISO 18869.
Mechanical Connection
The system that secures male and female coupling halves together: ex. ball locking, thread locking.
Max. Flow Suggested
Value of the maximum flow suggested for each series of products.
Max. Operating Pressure
The maximum value of pressure at which the product can be used.
Max. Residual Pressure During Connection
Maximum allowed residual pressure (pressure trapped in the circuit) to connect the coupler.
Max. Residual Pressure During Disconnection
Maximum allowed residual pressure (pressure trapped in the circuit) to disconnect the coupler.
Pressure Drop
Pressure lost between the inlet and the outlet of the coupling during operation.
Quick Coupling
A quick, easy, sure product to repeatedly connect and disconnect almost any fluid line in a system and to turn off the flow immediately upon disconnect.
Rated Flow
Typical rated flow relative to the size, in accordance with ISO norm standard.
Size
Nominal size of coupling body.
Spillage
Indicative value of the fluid loss per couple - uncouple cycle without residual pressure. Checked on sample in accordance with ISO norm test method.
Temperature Range
The temperature range recommended while using the couplers or valves.
Tightening Torque
Recommended torque to apply during connection on screw to connect couplings to prevent accidental disconnection.
Valve System
Type of valve used to shut-off medium flow in the male or female coupling half, once disconnected.
Breakaway
A safety feature for agricultural use couplings, where they automatically disconnect under excessive pull forces (e.g., equipment detachment), preventing hose rupture and oil spills as required by