Protan - Flexible Underground Ventilation Systems

Protan specialises in the design, production and manufacture of flexible underground ventilation through its Ventiflex range of webs and yarns for exclusive use in ventilation ducts.

Our weaving mill is ISO9001 and ISO14001-certified. The web is delivered from external suppliers to our own coating factory where a coating designed specifically for ventilation ducts is applied. The coating factory is also ISO9001 and ISO14001 certified. The coated material is delivered to our prefabrication unit where we manufacture ventilation ducts by means of specially designed automatic machinery.

The stable yarn

A stable yarn is important when you manufacture flexible ventilation ducts. It helps to maintain shape, gives better air transport and less turbulence. In order to ensure a high tear resistance, the yarn must still have a certain elasticity in case of overload. Through patience and comprehensive testing we have now found the optimal yarn.

To further strengthen the positive qualities we have tried new web combinations, which increase the tear resistance along the finished ventilation duct. The result is stable ventilation ducts with a strongly increased tear resistance along the entire duct. This gives fewer and shorter tears compared with conventional materials.

Where the remaining conditions are otherwise identical, our materials ensure a strongly increased airflow at the tunnel face and increased safety in the ventilation system. As far as we know, Protan Ventiflex is the only manufacturer to use these unique webs.

Suspension and mounting system

Ventiflex's mounting system has longitudinal suspension with welded PVC eyelets along the entire ventilation duct, which ensures optimal fastening and longitudinal stretching of the duct. The benefits of the Ventiflex system include:

• Longitudinal suspension
• If a PVC eyelet breaks, a new eyelet is already welded on 50cm away
• A welded PVC eyelet is much stronger than a brass eyelet
• The mounting points of a point-mounted system are fastened on a small piece of tarpaulin, and one often sees duct sagging between the points; should one of the mounting points break, the distance between the remaining points will be up to 2m, and the increase in load may result in the rest of the mounting points breaking and the entire duct falling down

Couplings

The coupling system includes several alternatives. Steel rings or flexible rings at one or both ends. Two tested types of coupling rings are VF couplings or LP couplings. Both models also come in two parts for easy installation of large diameters. Various types of zip couplings are also available.

Mounting

Many of our customers claim that the Ventiflex suspension system is the strongest on the market. It consists of a continuously welded longitudinal 'ridge' made of a special material. The suspension has welded PVC eyelets placed 50cm apart and several different steel hooks designed to ensure that the hook is the weakest point.

Thickness and weight

A thicker protective coating will, of course, be somewhat heavier. This is often used as an argument against Protan Ventiflex. With the complete system in place, the difference in weight will be equalised.

Protan Ventiflex weighs approximately 100g more per square metre. This means that with a duct diameter of 1,000mm, the weight of Protan Ventiflex will be approximately 2.85kg per running metre whereas the weight of competing products will be approximately 2.5kg per running metre.

When mounting the duct, a maximum of two running metres is lifted at the time. This means a total weight increase from 5kg to 5.7kg for a duct with a diameter of 1,000mm and an increase from 10kg to 11.4kg for a 2,000mm diameter duct. This weight increase is hardly a problem and is greatly outweighed by the advantages of increased wear resistance and better protection of the web. The possibilities of offering a safe, flame-retardant material increases with its thickness. It may, in other words, ultimately be a question of safety.