Description

The VCS flange gasket is a "Very Critical Service" gasket designed for electrical flange insulation and general sealing applications. This gasket is suitable for use in raised-face, flat-face and RTJ flanges in all pressure classes . In addition to its superior sealing characteristics and excellent dielectric properties, the VCS gasket is ideal for isolating flanges made from dissimilar metals (thus mitigating galvanic corrosion) and for mitigating localized flange face corrosion.

The VCS was originally designed to provide a reliable sealing solution for electrical insulation of critical flanges, particularly where phenolic ring gaskets had been failing in RTJ flanges.

Advantages & Benefits

Extreme high-reliability sealing and insulating solution for all critical services.
Seals and insulates at all pressures up through ANSI 2500 class and API 15000 psi service.
Withstands severe service conditions including large bending moments, vibration, temperature and pressure cycling.
Designed to withstand corrosive environments, including high concentrations of C02, H2S, produced water, etc.
Outstanding insulation properties for cathodic protection.
Pressure-activated seals provide high confidence sealing and eliminate costly leaks.
Gasket is sized to the bore to protect flange faces from media-induced corrosion and flow-induced erosion.
Prevents turbulent flow at flanged connections.
Mitigates galvanic corrosion in dissimilar metal flanges.
High-strength laminate material resists failure due to excess compression (i.e., over-tightening bolts).
Available to match any flange specification (ANSI, API, MSSP, BS, DIN, AS, others).
Can mate mismatched RTJ with raised-face flanges.
Easy installation, make-up and removal:
- Flanges do not have to be spread as with ring gaskets. The VCS easily slips into place.
- Sealing system results in low required bolt loads.
- Less make-up force is required resulting in less flange and bolt stress.
- Gasket is self-aligning and centering, quick to install. No special tools are required.
Maintenance-free, corrosion-resistant design is resistant to deforming under load, which makes the gasket reusable

VCS Design
The unique and patented design of the VCS gasket incorporates high-strength, glass-reinforced epoxy laminate bonded to a stainless steel core. This provides the strength of a traditional metallic gasket while maintaining complete electrical insulation between the flange faces. Seal grooves are machined through the laminate insulating material and into the stainless steel core. This provides a strong base for the seal to seat into and breaks the potential leak/weep path that is inherent in glass laminate materials. Spring-energized Teflon internal face seals are installed in the dovetail-shaped seal grooves to provide the trademark pressure-activated sealing that distinguishes the VCS from all other high pressure insulating gaskets (Viton o-rings also available if specified).

Electrical Insulation

In addition to its superior sealing characteristics, the Pikotek VCS distinguishes itself by providing electrical flange insulation in a high-strength gasket. The VCS significantly decreases electrical potential between two flange faces by providing a non-conducting, non-metallic interface. This effectively eliminates corrosion resulting from dissimilar metals contact or ground current induced corrosion of metal piping components. When used with insulating sleeves and washers, the VCS is particularly effective in breaking electrical conductivity in piping systems with cathodic protection systems.

What makes the VCS unique among insulating gaskets is its strength and durability. Traditionally, insulating gaskets have been fragile and prone to failure because they are often made from brittle, non-metallic materials (i.e., phenolic resin) and are not capable of withstanding imperfect installation practices. The VCS's steel core and patented construction enables the gasket to withstand far more system pressure, pressure cycling, bending moments, over-torquing and overall abuse than conventional insulating gaskets with zero risk of product failure.

Sealing Characteristics

The primary job that any gasket must perform is to seal the pressure differential between the internal and external environment. The VCS performs this task through the use of its spring-energized, pressure-activated sealing elements. At low system pressure, the spring acts to deflect the lips of the seal, thus enabling low pressure sealing. As the pressure increases and comes in direct contact with the sealing element, the system pressure energizes the lips of the seal against the flange face and the stainless steel core. The greater the pressure, the more sealing force is applied against the flanges. This high pressure sealing is accomplished while maintaining complete electrical flange insulation. This high-reliability sealing system makes the Pikotek VCS the gasket to use when gasket failure cannot be tolerated.

The fact that the VCS uses pressure-activated sealing elements which are located inboard of the ring groove on RTJ flanges has the additional benefit of allowing the VCS to seal mismatched RTJ to raised-face or flat-face flanges. This feature is very useful when replacing valves using stock inventory that may have a different flange face than the mating flanges.