Roxtec MCT – the multi-cable transit system

Roxtec MCT devices represent cutting-edge technologies that have proven their safety record in the harshest conditions within offshore oil, gas and marine projects as well as in a multitude of demanding landbased projects in a wide range of industries. Upcoming projects striving for improved safety, increased efficiency and lower total cost of ownership should also include Roxtec MCTs into owner-level approvals, standards and specifications for cable entries.

Here we present examples of where you can ensure safety with Roxtec multi-cable and pipe seals, and recommend a smooth design work process for MCTs.

Application areas for the Roxtec MCT, multi-cable transit system: 

Fire barrier

Roxtec MCTs, multi-cable transit devices, have a long and proven history of providing protection against fire. One of the most efficient applications for Roxtec multi-cable transit devices is when a design must provide fire protection, but also has one or several demands to protect against water, smoke, blast, rodents or other hazards. When a complete risk assessment is included within the project design, the risk of fire is often associated with the risk of damage from other hazards related to it. In these cases, it is recommended to use Roxtec MCTs.

Environmental and water ingress protection

Roxtec MCT devices protect against the elements and hazards caused by weather as well as splashing or hose-down water, sand and dust. Standard Roxtec MCT designs have a minimum rating equivalent to an IP (ingress protection) rating for electrical enclosures of IP 54 as defined by IEC 60529. Performing at higher levels of dust and water protection, Roxtec provides standard MCT products with IP 66 and IP 67 ratings and an additional capacity to prevent the passage of corrosive or potentially explosive gases.

Learn more about water-tightness and water ingress protection tests.

Hazardous locations

In addition to MCTs, multi-cable transit devices, for entries into buildings, Roxtec has developed MCTs that meet major international electrical schemes (IEC, ATEX and AEX) for the use of multi-cable transit devices to seal cables entering electrical equipment or enclosures within designated hazardous or classified areas. In these applications, the MCT device must be an approved device or component to the equipment or enclosure. When MCTs are mounted directly into electrical equipment or enclosures, it may be necessary with a cable entry scheme certified to a hazardous location standard, such as ATEX, IEC 60079-0 or an accepted engineering practice such as API RP 500/505.

Vapor-tight barrier

During the planning of hazardous areas for a facility, design considerations must be taken to separate them from unclassified areas. During this phase, it is important to design cable entry methods to buildings in the hazardous zones, with vapor-tight barriers between them and non-hazardous locations. The vapor barrier must prevent the migration of fugitive emissions under normal ambient pressure conditions. With proper specification, design and installations, Roxtec MCT devices meet or exceed the requirements. Roxtec MCTs can provide certified gas-tightness to a catastrophic pressure of 2.5 bar (~36 psi) in demanding offshore applications, and they can easily meet onshore requirements aiming at maintaining a pressure slightly positive to atmosphere.

Earthing, bonding and EMC

Many project designs are using armored cable types for power and control systems, and international and national electrical codes require either bonding or earthing of the armor jacket component. Roxtec has developed MCT designs to meet all the specific requirements. Roxtec MCTs typically include a tin-plated copper earthing strap embedded into the module. Roxtec MCT solutions are also approved to provide equipotential bonding as well as electrical safety protection against the effect of lightning strikes, as identified by IEC-62305.

Read more about Roxtec BG™ (bonding and grounding) solutions and solutions for electromagnetic compatibility.

Learn about how we perform short circuit grounding tests or electromagnetic shielding tests.

Cable retention and pull force

The design and materials of Roxtec MCT devices provide high levels of cable retention for both vertical installations in walls and horizontal installations in floors. Roxtec MCTs are tested for cable retention to perform to the same requirements as traditional metallic cable glands, as defined in EN 50262 for Type B cable glands, IEC 62444, and also as stated as the minimum “pull force” in UL 514B, Table 27. As an example, for 50mm O.D. cables, Roxtec MCT devices are tested to provide cable retention of >2000 NM (~450 pound-force).

Rodent and insect barrier

From arctic conditions to hot and harsh deserts, rodent and insect infestations have caused downtime for power generating facilities and various processing plants. Pests seek refuge in buildings or cabinets sheltering electrical control equipment and destroy sensitive cables, connections or wiring, causing standstill and costly repairs or replacement of equipment.

Roxtec MCT devices efficiently prevent snakes, rodents and harmful animals from entering where cables and pipes enter or exit buildings.

Blast-rated structures

Due to the potentially explosive environments of oil, gas and petrochemical facilities, many engineering hours are spent on designing blast-rated walls and structures, but the openings where cables pass are often forgotten. Roxtec MCT devices must always be included in early project designs, with civil and/or structural design teams confirming with Roxtec that the cable and pipe transit design provides the required level of blast load protection. Ratings for blast-rated structures vary, but Roxtec can provide test reports for specific demands.

Vibration and noise damping

The components of Roxtec MCT devices that are in contact with cables and pipes are made of elastomeric polymers and provide vibration and noise reduction performance. Owners and operators of skid-mounted turbine equipment, generators, motors, mining equipment and cranes specify Roxtec MCTs, with vibration and noise damping as one of the protective benefits.

Cable terminations

With the increase of modular building packages for substations, control centers and analyzer buildings, Roxtec MCT devices are becoming common in designs with cables entering through the floor directly below electrical equipment. In these cases, the Roxtec MCT frame is welded or bolted to the floor at strategic locations for cable termination of the equipment. The cables are routed through the frame and sealed with the modules and compression unit. The Roxtec MCT device provides cable retention in addition to an approved barrier against environmental risks, such as water, and against fire, gas, blast, and rodents.

Extreme environments

Many of today’s largest industrial projects are being constructed in the world’s most harsh and hazardous environments. These projects are required to perform at the same or higher levels of safety when compared to projects in areas that are easy to manage.

The history of Roxtec MCTs versus hazards and harsh environments within onshore oil and gas and offshore oil and gas has proven the ability of the multi-cable transit system to endure truly extreme conditions.

Retrofit for existing cables and pipes

Many existing facilities are operating without any original attempt to seal cable entries into buildings. Others have at least tried to seal entries using sub-standard methods. Roxtec MCT devices are available with bolt-together retrofit frames for installation around existing cables and pipes. It is therefore possible to raise the safety and reliability level in brownfield projects by using Roxtec multi-cable transits for risky penetrations in buildings and equipment.