What is a RF Pipe Penetration?
A RF shielded Pipe Penetration is a specific type of penetration made to maintain RF attenuation while allowing liquids, gas and fibre optics to pass though. They achieve this by conforming to conforming to the waveguide beyond cut-off principle. The core holes size and length of the core will vary depending on the required frequency. These pipe penetrations after often used for fire suppression systems such as VESDA systems, fibre optics for camera systems and data centres, pneumatic piping for control systems for doors and antenna systems.
In summary, RF Pipe Penetration is a solution for allowing the passage of fibre optics, liquid or gas through metal pipes while maintaining RF attenuation and minimising signal loss and interference.
Our services
MDL Technologies offer a wide range of pipe penetrations for RF shielding in most sizes for water, gas, or air. As well as specially designed pipe penetrations assemblies used for transporting non-conductive gases or liquids into an enclosure.
MDL can also manufacture specialty one-off pipe penetrations for unique applications.Â
- Accommodate Requirements Such as Fire Suppression Systems, Hydraulics, and other Utilities
- Honeycomb Waveguide Insert Option Available for High Frequency or Gaseous Applications
- Dielectric Unions are Available to Maintain Isolation to the Ground
Calculating RF pipe penetration sizes
For circular waveguides:
fc = c/3.412r
where:
fc = cutoff frequency
c = speed of light, 1.181 x 1010 in/s
r = radius of circular waveguide in inches
General Rule of Thumb:
For circular waveguides, make sure the waveguide length is at least four times the diameter.
| Diameter of Waveguide | Frequency Cutoff |
|---|---|
| 1.27 cm (.5 in) | 13.8 GHz |
| 1.91 cm (.75 in) | 9.2 GHz |
| 2.54 cm (1 in) | 6.9 GHz |
| 3.175 cm (1.25 in) | 5.5 GHz |
| 3.81 cm (1.5 in) | 4.6 GHz |
| 4.08 cm (2 in) | 3.5 GHz |
| 6.35 cm (2.5 in) | 2.8 GHz |
| 7.62 cm (3 in) | 2.3 GHz |
| 8.16 cm (4 in) | 1.7 GHz |
ETS-Lindgren Stock RF Pipe Penetrations
| Waveguide Feed-through Part Number | With Dielectric Option Part Number | Nominal Pipe I.D. | Length | Installation Hole Size |
|---|---|---|---|---|
| 551060 | 551084 | 1.27 cm (.5 in) | 15.24 cm (6 in) | 2.22 cm ( .875 in) |
| 551061 | 551085 | 1.91 cm (.75 in) | 15.24 cm (6 in) | 2.86 cm ( .125 in) |
| 551062 | 551086 | 2.54 cm (1 in) | 15.24 cm (6 in) | 3.49 cm (1.375 in) |
| 551063 | 551087 | 3.175 cm (1.25 in) | 15.24 cm (6 in) | 4.46 cm (1.75 in) |
| 551064 | 551088 | 3.81 cm (1.5 in) | 15.24 cm (6 in) | 4.92 cm (1.9375 in) |
| 551065 | 551089 | 4.08 cm (2 in) | 20.32 cm (8 in) | 6.35 cm (2.5 in) |
| 551066 | 551090 | 6.35 cm (2.5 in) | 20.32 cm (8 in) | 7.30 cm (2.875 in) |
| 551067 | 551083 | 7.62 cm (3 in) | 30.48 cm (12 in) | 9.21 cm (3.625 in) |
| 551068 | 551091 | 8.16 cm (4 in) | 40.64 cm (16 in) | 11.75 cm (4.625 in) |
