GN 7404 Pressure Equalization Plugs Stainless Steel, Oil / Water Repellent



Product Family Stainless Steel

Standard parts made of rustproof stainless steel have been designed for use in the food sector, in the chemical industry, for aggressive ambient conditions or for outdoor use.

  • corrosion-resistant
  • precise fit
  • environmentally friendly
Show all Stainless Steel products

Product description


GN 7404 pressure equalization plugs are used in enclosure and device construction. In an enclosure wall, they ensure pressure compensation between the enclosure interior and the outside.

Any possible dirt and dust particles carried by the gaseous medium, but also oil and water drops, are retained. This protects the enclosure interior from contamination and moisture and also prevents e.g. oil from dripping into the surrounding area.

In order to protect the membranes, they should not be completely covered with oil or water, and the differential pressure / air outlet volume should not be exceeded. They should be installed on the side / vertically in a protected position.

The outer diameter of the enclosures with recessed hexagon is chosen to match screw-in holes for tube connections according to DIN 3852.

The seal is embedded in a radial groove and can therefore not be lost or squeezed out during the tightening operation.

Assembly note:
For wall thicknesses below 4 mm, use GN 7430 thin hexagon nuts.


Stainless steelNI AISI 303

Polyamide fleece, non-woven /
acrylic copolymer wetting

Membrane bezel
Technopolymer (Polyamide PA)
  • Glass fiber reinforced
  • Temperature resistant up to 212 °F (100 °C)

Protective strainer
Stainless steel AISI 304

Seal / O-ring
Rubber NBR (Perbunan®)

RoHS compliant


Thin hexagon nuts GN 7430

On request

Body in brass
Other membrane pore sizes

Technical drawing

Hide technical drawing
GN 7404 Stainless Steel Pressure Equalization Plugs, Oil / Water Repellent sketch

Part Options / Table

Show / Hide columns


Dimensions in: Inch | Metric
Pipe thread

Fine thread
d2d3l1l2sMembrane pore size
in µm
Differential pressure Δ 1 bar
Air outlet volume
in l/min
G 1/2M 20 x
G 3/4M 26 x
G 1M 33 x 1.51.570.790.430.331.421.234

Build & Price

3D Product Configurator

Pipe thread d1
Fine thread d1
Membrane pore size

Membrane structure – Materials

The membranes consist of a polyamide fleece as a substrate with a completely unordered
structure. The minuscule membrane pores are created by saturating the fleece fibers with an acrylic copolymer, which completely wets them but does not fill the spaces between the fleece.

During manufacturing, the material and process parameters affect the pore size, which is between 0.2 and 10 µm. The quality of the membrane can be determined by means of “porometry”, a rating method which assesses the size distribution of the membrane pores and the air outlet. To illustrate this, a microscopic image of the cross-section of a membrane is shown on the right hand side.


For comparison: The minimum mesh width of a filter manufactured using economically viable methods is 50 μm.

Membrane, microscopic images,
2000x magnification

Functionality – Service conditions – Installation position

The membranes repel oil and water because of their materials and surface structure. This prevents water and oil droplets from completely suffusing the membrane surface. This repellent property is supported by installing the plug on the side in a vertical position. If, in exceptional cases, the membrane is compelety covered, small amounts of oil or water can be pushed through the membrane at certain differential pressures. Once the situation has been rectified, the oil and water will drip off, and the membrane will be fully functional again.

Technical parameters

When using pressure equalization plugs, the maximum air outlet volume, the maximum differential pressure as well as the maximum rated / burst pressure are of importance. The achievable air outlet volume depends linearly on the differential pressure, which should not exceed 1 bar.

Air outlet volume dependent on differential pressure

Differential pressure, burst pressure

Skizze Luftdurchlassvolumen Skizze 2 GN 7404


Thermal -

The membrane enclosure may not be used in temperatures exceeding 100 °C. The membrane itself can resist temperatures of up to 150 °C.

Chemical -

The membranes are resistant to a wide range of chemical substances frequently used in machine and automotive engineering, e.g., oil,
fuels, organic solvents, and alcohols. In case of doubt, a tolerability test should be carried out.

Selected Part

Total US Dollars (net)
In stock: 0
Call / Email for Delivery Time
Please note our quantity discounts (US Dollars).
≥ 250$13.68
Prop 65: Not compliant
Cancer and Reproductive Harm -
RoHS: Compliant
This article is RoHS-compliant in application of Annex III., which means it complies with EU Directive 2011/65/EU, including extension (2015/863/EU), for restricting the use of certain hazardous substances in electrical and electronic devices. The Directive regulates the use of hazardous substances in devices and components. The implementation in national law is summarily described with RoHS(Restriction of (the use of certain) hazardous substances)).
Weight: 0.051 lbs
If weight is not listed, please contact our Sales Department for additional information regarding weight.
Phone: 800-877-8351
All Prices are in US Dollars. Taxes Not Included.

CAD Download

Email CAD File

To receive an email with a CAD download without creating an account, please enter your e-mail address. Max of 3 CAD files per day unless you create an account.

Please enter the code you can find in the picture.

CAD Download Tutorial About CAD Downloads
Save as Favorites

Please enter the code you can find in the picture.

Need Help?

Our service team is available from Monday to Friday between 7:30 AM and 5:00 PM Central Time: 800-877-8351

Special Requests | Contact our sales team

This could also be interesting...

An error has occurred!
We have received your callback request and will contact you soon.
JW Winco Services

Our service team is available from Monday to Friday between 7:30 AM and 5:00 PM Central Time

Request Callback
Your Contact

You are looking for a Winco partner near you? Please select the country.