Bolt Insulation

In the complex world of industrial operations, a tiny, often overlooked component plays a pivotal role in ensuring safety, longevity, and efficiency. Bolt insulation provides critical barriers that prevent common, yet costly, problems in pipelines, structural connections, and electrical systems across various sectors, including oil and gas, chemical processing, and power generation.

Lamina was the first company to provide a full range of Imperial and Metric standard sizes to meet international studding sizes and flange hole dimensions.

Bolt insulation is typically provided as part of a flange insulation kit comprising an insulating gasket, sleeves for each bolt, and insulating washers, and offers a multitude of benefits that safeguard infrastructure and optimise performance.

Types & Sizes

Lamina manufactures a range of metric and imperial bolt insulation products of different types, sizes and lengths, as well as bespoke options on request.

Imperial Sizes

Available made from Mylar Polyethylene Terephthalate with a separate range made from Nomex Polyamide paper. All imperial tubes have a wall thickness of 0.031″. Supplied in 3′ and 6′ lengths for the USA market.

Metric Sizes

Available made from Mylar Polyethylene Terephthalate, with a separate range made from Nomex Polyamide paper. The metric Mylar tubes are identified with a blue stripe to clearly differentiate them from the imperial sizes. Metric tubes have a wall thickness of 0.5mm. Supplied in 1m and 2m lengths.

A detailed data sheet is available for download.

Applications

1. Mitigation of Galvanic Corrosion

Perhaps the most significant advantage of bolt insulation is its ability to combat galvanic corrosion. This type of corrosion occurs when two dissimilar metals come into contact in the presence of an electrolyte – such as moisture, saltwater, or process fluids – creating a galvanic cell where the more anodic metal rapidly degrades.

In a flanged connection where a carbon steel pipe might connect to a stainless steel component, bolt insulation electrically isolates the components, breaking the circuit and preventing the flow of corrosive current. This protection is vital in harsh, corrosive environments, extending the lifespan of critical equipment and preventing expensive replacements and downtime.

2. Enhanced Cathodic Protection Systems

In extensive piping networks, cathodic protection systems are often employed to prevent external corrosion on buried or submerged pipelines. Bolt insulation kits are essential for isolating different sections of the pipeline, allowing engineers to apply current more efficiently and contain the protective measures to specific, targeted areas. This ensures the entire system remains protected against stray currents that could otherwise lead to pitting and premature failure.

3. Prevention of Electrical Hazards

Beyond corrosion control, bolt insulation provides a crucial safety function by ensuring electrical isolation in potentially hazardous environments. It prevents the unintended flow of static charges or stray electrical currents through piping systems – a major concern when handling volatile or flammable fluids in industries like oil refineries and petrochemical plants. By eliminating potential electrical paths, insulation kits drastically reduce the risk of electrical arcing and explosions, protecting personnel and equipment.

4. Thermal Insulation and Energy Efficiency

In applications involving high or low temperatures – such as steam lines or cryogenic systems – bolt insulation helps to minimise heat transfer between pipes and structural components. This contributes to overall energy efficiency by maintaining process temperatures, and enhances safety by reducing the surface temperature of hot flanges, protecting workers from accidental burns.

5. Long-Term Reliability and Reduced Maintenance

By addressing the root causes of corrosion and electrical issues, bolt insulation significantly extends the operational life of components. The use of durable, high-dielectric strength materials – Mylar A, or a combination of Mylar A and Nomex – ensures stable, long-lasting performance even under challenging conditions. The result is reduced maintenance frequency, lower operational costs, and increased system integrity and reliability over many years of service.