Noble Gases and Vacuum
Nitto Kohki Pneumatic Solutions
Nitto Kohki PCV Cupla quick couplings are designed for noble gas lines and vacuum applications where leak-tightness and media purity are critical. The 95-item range covers the PCV series in brass with two seal options: CR (chloroprene, for general vacuum and inert gas service) and FKM (fluoroelastomer, for elevated temperature and chemical resistance). The PCV470, PCV600, PCV630, PCV800, PCV950, PCV1270 and PCV1590 series cover a broad connection range, each with -0, -2 and -3 suffixes for different port geometries.
The brass body and precise valve geometry minimise dead volume during coupling and prevent contamination of the gas line with atmospheric air. Both seal variants (CR and FKM) are suitable for inert gases such as nitrogen, argon and helium as well as for vacuum lines.
| Series | CR seal | FKM seal | Port types |
|---|---|---|---|
| PCV470 | PCV470-0, -2, -3 | PCV470-0, -2, -3 (FKM) | 0, 2, 3 |
| PCV600 | PCV600-0, -2, -3 | PCV600-0, -2, -3 (FKM) | 0, 2, 3 |
| PCV630 | PCV630-0, -2, -3 | PCV630-0, -2, -3 (FKM) | 0, 2, 3 |
| PCV800 | PCV800-0, -2, -3 | PCV800-0, -2, -3 (FKM) | 0, 2, 3 |
| PCV950 | PCV950-0, -2, -3 | PCV950-0, -2, -3 (FKM) | 0, 2, 3 |
| PCV1270 | PCV1270-0, -2, -3 | PCV1270-0, -2, -3 (FKM) | 0, 2, 3 |
| PCV1590 | PCV1590-0, -2, -3 | PCV1590-0, -2, -3 (FKM) | 0, 2, 3 |
Typical applications: Nitrogen, argon and helium supply lines in laboratory and production, vacuum lines in analytical instruments and semiconductor fabrication, inert shielding gas feed for welding, laser cutting gas supply, and applications where leak-tightness and minimum contamination of the gas line are essential.
Series in this category compared
Maximum working pressure is the first selection criterion. It decides the series, not the size: a low pressure coupling does not become high pressure capable by choosing a larger bore.
| Series | Max working pressure | Sizes | Shut-off type | Fluids | Body material | Catalogue page |
|---|---|---|---|---|---|---|
| PCV PIPE CUPLA | 45 bar | Copper pipe outside diameter 4.0 mm to 15.88 mm; end thread 1/4 inch and 3/8 inch | Valveless | Inert gas, Vacuum, Air, Gas | Brass | 151 |
| SP-V CUPLA Type A | 3.0 to 7.5 MPa {31 to 76 kgf/cm2} | 1/4 inch to 3/4 inch | Two-way shut-off | Inert gas, Vacuum, Gas, Air, Water | Brass (Standard material), Stainless steel (Standard material), Stainless steel (Made-to-order item) | 149 |
The four shut-off types
The shut-off type decides what happens on disconnection. It is the second criterion and depends on whether the line is under pressure when it is parted and how much fluid may escape.
Choosing a coupling in five steps
- Fix the fluid and the operating temperature, which gives the seal material.
- Determine the maximum working pressure, which gives the pressure class and the series.
- Choose the shut-off type: one-way, two-way, valveless or flat face.
- Fix the end connection and size: hose barb, male thread, female thread or tube fitter.
- Choose the body material for the fluid and the environment, then order plug and socket as a pair.
This page is based on the Nitto Kohki general catalogue Quick Connect Couplings C01en-b, 190 pages. The complete catalogue is available for download on this page.
