Pepperl+Fuchs Blog

5500 Series Type Z Purge Control System with Pressure Relief Vent

Posted by Chris Romano on Thu, Oct 09, 2014

Part 2- The pressure relief vent

The 5500 series is a Z purge system and Ex pz purge system. Part 2 of this product introduction gives an overview of the pressure relief vent and associated components for the vent system.


These type Z purge units are certified for ATEX, IECex, NEC class/divisions - Class I, Division 2 and Class II, Division 2, groups A-D and E, F, G, Zone 2 and 22.




Welcome to Pepperl+Fuchs' presentation of the Z purge 5500 series components. This is a Type Z/ Ex pz system. My name is Chris Romano, and I am the product portfolio manager for purge systems here at

Today we're going to be talking about the 5500 series Z purge system. It's made up of the control system, which here, we have an internal mount unit and an external mount unit along with some mounting hardware. The vent, which is required for purge/pressurization for the relief vent, and optional solenoid valves to get the protective gas inside the enclosure for purging and pressurization.

The 5500 system also requires a pressure relief vent. For the pressure relief vent, we offer the EPV-5500. This vent comes in three different sizes. The first size is going to be used for very large enclosures where the leakage through the vent isn't all that important, but the flow rate is. This vent is going to allow for
higher flow rates to flow through the vent and keep the enclosure pressure low. For medium size enclosures, we have a vent that gives you a little bit better seal through the vent. It has a little bit
higher enclosure pressure for the same amount of flow. Then we have another vent that has a plunger with a gasket on it that will give you a very well-sealed vent. This is mostly used for nitrogen-based or bottle-type air sources, where the conservation of air is very important for the enclosure. This vent can also be used for smaller enclosures, because the flow through this vent is lower than the other two systems.

With the vent, we have some components here. These involve the body of the system, which has a component almost like a check-valve, along with a cap that has a spark arrestor, which is required for the standards. The cap can be rotated. Along with this vent, we include a hex key so that you can loosen the cap and then rotate it so that it is facing down and away from water sources. The vent is also available with a stainless steel cap or an anodized aluminum cap.

The body of the vent system is 6061-T6 anodized aluminum, which is great for sea-water or water applications. For customers that require all stainless steel, we offer this cap. Now, this unit can be mounted on the outside of the enclosure through this sealing washer and nut. This is a one and a half inch NPT  pipe opening. It would fit into the enclosure, and then you would seal your enclosure. The sealing washer would be on the enclosure and then you would use the nut to seal from the inside.

For those customers that need all stainless steel, or if they want to put the vent inside the enclosure, they can remove the cap, and then the cap pipe opening would go inside the enclosure, and you would mount the sealing washer on the outside, screw it down with the nut to provide a seal, again, the vent is inside the enclosure, and then you would put the vent cap on the outside and tighten it down, so that the only thing showing would be the cap. That would give you an all stainless steel type system.

That completes the explanation of the components for the 5500 series Z purge system. We have the control units (external mount or internal mount) with the mounting hardware, and the vent, which is a pressure relief vent. These items are required for type Z, Ex pz system.

Next, we offer these optional manifold systems for getting purging and pressurization of the enclosure. Again, the manifolds are an optional system. You can certainly use manual valves, you can use your own valving system, because again, the purge flow is based on the pressure inside the enclosure, which is measured through the control units. These units are certified for ATEX, IECex, NEC class/divisions - Class I, Division 2 and Class II, Division 2, groups A-D and E, F, G, and Zone 2 and Zone 22. So they are good for gas and dust atmospheres.

More on this topic

Part 1: 5500 Series Type Z Purge Control System for Division 2 or Zone 2

Part 3: 5500 Series Ex pz Purge System with Optional Manifold

Questions about Purge Systems? Get the Engineer's Guide


Topics: Purge/ Pressurization Systems

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