Rotary Plug

Quick couplings

The Nitto Kohki Rotary Plug is a quick-coupling plug in steel with NBR seal and an integrated swivel connection. Three types are offered: RL-20PM, RL-30PM (metric thread, nominal sizes 20 and 30) and RL-20PFF (flange port, nominal size 20). The rotary function allows the connected line to rotate freely without generating torsional stress or hose twisting.

Integrated swivel joint - free line rotation without torsional stress
Steel construction - for continuous operation in industrial compressed-air systems
NBR seal - suitable for dry and oil-mist compressed air
Sizes 20 and 30, PM and PFF - metric thread and flange port selectable

TypeNominal sizePortMaterialSeal
RL-20PM20Metric (PM)SteelNBR
RL-30PM30Metric (PM)SteelNBR
RL-20PFF20Flange (PFF)SteelNBR

Typical applications: Compressed-air supply to rotary tables, indexing units, and pivoting fixtures, pneumatic tools with continuous rotational motion, robot joints and pivot arms, and any application where a freely rotating air connection must eliminate hose twisting and line fatigue due to torsion.

Technical data from the manufacturer catalogue

SeriesROTARY PLUG
Body materialSteel (Nickel plated)
Seal materialNitrile rubber (NBR)
Max working pressure1.5 MPa {15 kgf/cm2}
Working temperatureNitrile rubber (NBR): -20 to +80 deg C
Valve structureOne-way shut-off
Applicable fluidsAir
Vacuum serviceNot suitable for vacuum application in either connected or disconnected condition.
Size range1/4 inch, 3/8 inch
Catalogue pageC01en-b, 63

Operating principle

One-way shut-off (valve in the socket)One-way shut-off (valve in the socket)shut-off valve in socketplug without valveSocketPlugFlow direction: socket to plug
On disconnection the valve in the socket closes the supply line. The fluid left in the plug escapes.
Connecting in three stepsConnecting in three steps1. Pull the sleeve back2. Push the plug fully home3. Release the sleeve, balls lockSingle hand operation. Depressurise the line before disconnecting.
Connecting sequence of a ball locking quick connect coupling.
  • Rotary function allows 360 deg swivelling.
  • Big improvement for handling of pneumatic tools.
  • Rotary neck plug for hose connection to pneumatic tools and pneumatic devices.
  • Fits at 45 deg angle to the tool eliminating annoying offset load caused by connected hose.
  • Ideal compact design enables optimum workability by simple body structure. Now far lighter and smaller than conventional models.
  • New dust-proof design for increased durability.
  • For air tackers, nailers, impact wrenches and other pneumatic tools.
  • Ideal body angle achieved by the plug allows comfortable use of tools even in narrow places and overhead work.

All models of the series

PM - Male thread

ModelCoupling partApplicationSteel (g)LøDT
RL-20PMPlugRc 1/452(52.1)(34.1)R 1/4
RL-30PMPlugRc 3/873(50.8)(32.8)R 3/8

PFF - Female thread

ModelCoupling partApplicationSteel (g)LøDT
RL-20PFFPlugG 1/457(51.3)(33.3)G 1/4

Dimensions in millimetres. Values in brackets apply in the connected condition.

Legend: L = overall length; H = width across flats or outside dimension; D = socket outside diameter; A = hose barb length; C = sleeve dimension; T = thread or barb size; B = bore

Series comparison

SeriesMax working pressureSize rangeValve structureApplicable fluids
COMPACT ZEROSPILL CUPLA10 barThread 1/8 inch, 1/4 inchTwo-way shut-off (Spill Reduction)Air, Water
CUPLA HOSE with FULL BLOW CUPLA10 barHose size ø5 mm×ø8 mm, ø6.5 mm×ø10 mm, ø8.5 mm×ø12.5 mmOne-way shut-offAir
FLOW MONITOR10 barRc 3/8 and Rc 1/2-Water
ROTARY PLUG15 bar1/4 inch, 3/8 inchOne-way shut-offAir
ANTI-VIBRATION PLUG HOSE15 barR 1/4 (SHA-3-2R), R 3/8 (SHA-3-3R)One-way shut-offAir
HI CUPLA BL15 bar1/4 inch, 3/8 inch, 1/2 inch (thread and hose barb); SN type for urethane hose: for 6.5 x 10 mm, 8 x 12 mm and 8.5 x 12.5 mm hoseOne-way shut-offAir, Water
FLATFACE CUPLA F35350 barThread 1/4 inch, 3/8 inch, 1/2 inch, 3/4 inch, 1 inchTwo-way shut-off (Spill Reduction)Hydraulic oil
FLATFACE CUPLA FF350 bar3/8 inch, 1/2 inch, 3/4 inch, 1 inch (thread)Two-way shut-off (Spill Reduction)Hydraulic oil

ROTARY PLUG is the plug to take when the hose has to follow the tool: at 1.5 MPa {15 kgf/cm2} and one-way shut-off it matches the pressure class and valve type of HI CUPLA BL, NUT CUPLA, LOCK CUPLA 200, HI CUPLA Two Way Type, ROTARY LINE CUPLA and ROTARY FULL BLOW LINE CUPLA, so it changes neither the pressure class nor the valve behaviour of such a line. TWIST PLUG and COMPACT ZEROSPILL CUPLA stay at 1.0 MPa {10 kgf/cm2}; COMPACT ZEROSPILL CUPLA shuts off on both sides and is the choice when spill at disconnection weighs more than the swivel. ROTARY PLUG is offered in 1/4 inch and 3/8 inch, so within that size range the decision rests on the swivel requirement rather than on the pressure rating.

Body and seal materials

Body material
Steel (Nickel plated)
Seal materialMarkWorking temperatureRemarks
Nitrile rubber (NBR)--20 to +80 deg C-

Further catalogue data

NoteValue
Maximum tightening torque, Nm {kgf cm}1/4 inch : 14 {143}, 3/8 inch : 22 {224}
Flow directionFluid flow can be bi-directional when socket and plug are connected.
Minimum cross-sectional area (mm2)RL-20PM : 28, RL-30PM : 28, RL-20PFF : 28
Working pressure, other units15 kgf/cm2 / 15 bar / 218 PSI
Neck angle135 deg as dimensioned on the drawings, that is 45 deg to the tool

Interchangeability and size groups

Interchangeable with sockets of HI CUPLA models 10, 17, 20, 30, 40 and 60. Interchangeable with each models of NUT CUPLA series and HI CUPLA series (except models 400, 600, and 800). Please see page 21 for HI CUPLA Series Interchangeability.

Safety and application notes

  • Before use, please be sure to read the Safety Guide described at the end of this book and the Instruction Sheet that comes with the products.

All technical data on this page is taken from the Nitto Kohki general catalogue Quick Connect Couplings C01en-b, page 63. The complete catalogue is available for download on this page.

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  1. Coupling plug Rotary Plug RL-20PFF, steel - Nitto Kohki 317610250
    €11.88