PIKOTEK


                                                         
                                                
                                    


VCS Flange Gasket

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.

 

The VCFS* utilizes Pikotek’s standard VCS design with its 20 plus year track record of success in sealing Very Critical Service. The FS* version was created by taking a standard VCS configuration and adding a secondary sealing element that is capable of maintaining a seal while subject to a 1500ºF (800ºC) fire. The VCFS* combines the VCS’s proven track record of electrical isolation and sealing integrity in aggressive situations with a solution that has fully passed the API 6FB, 3rd Edition fire test.

The VCFS* is suitable in all services up to and including ANSI 2500# and is offered for ring type joint (RTJ) flanges from 6”- 24” and raised face flanges from 2”-24”. The VCFS* is designed for service where the cost of joint failure cannot be tolerated and the operator desires both electrical isolation and added sealing integrity in the case of a fire.

The VCFS* consists of a PTFE spring-energized primary sealing element and an E-ring secondary seal, all seated in a high-strength metal core upon which an insulating laminate is permanently bonded. Due to its unique pressure activated sealing mechanism, the gasket requires far less bolt stress to seal than other gasket types. In addition, the engineered E-ring will serve as a secondary seal during normal operation and the primary sealing element during a fire.

* Note: The “FS” or “Fire Safe” designation denotes only that this gasket has successfully passed the API 6FB fire test. Due to the fact that every fire is unique and many uncontrolled variables are present, no other claims regarding suitability or performance in a fire are made. Each designer, user and/or operator will need to assess their individual situation when deciding to install FS style gaskets. Patent Pending.

 

Flowlok

Flowlok flange connections are designed to minimize fugitive emissions in bolted end-connections through the use of a patented dual seal design that "locks" in the media and improves flange sealability when compared to conventional flange gasket technology even in connections with imperfect flange faces.

The Flowlok is composed of essentially two independent sealing components, a high modulus composite-lined structural seal retainer and a secondary pressure-energized radial face seal. The primary sealing element is the composite seal retainer lining material located outside of the secondary radial face seal.

The gasket lining material is composed of a structurally rigid, yet superficially compressible material such as a glass-reinforced polymer (glass-reinforced epoxy, silicon, melamine or polyimid) or other non-asbestos, high-temperature polymer material which can then be coated with either Buna N rubber or chemical resistant neoprene. This material possesses good compressive strength while also providing a positive seal. The result is sealability without material deformation. The secondary face seal material is the key to fugitive emission minimization. The standard seal is a helical wound spring-energized Teflon lip seal. For nonstandard applications, Teflon can be substituted with a wide range of other superior elastomeric and non-elastomeric face seal materials (see section on Seal Materials).

The Pikotek Flowlok is designed for use in all ANSI and API class flanges including ring-joint (RTJ), raised-face, and flatface (or combination) flanges. This means that the Flowlok can be used to mate dissimilar flange types as well

Firelok (API 6 FB fire tested)

The Firelok flange connection offers all of the features and benefits of the Flowlok with the added feature of a patented fire-resistant "piston" seal which is designed to capture the media in the event of ultra-high temperature (hydrocarbon) flame impingement such as would be present in a runaway hydrocarbon fire.

The Firelok connection with fire-safe metal-to-metal backup seals has passed the API 6 FB destructive fire test for bolted end-connections (2,000 degrees F for 30 minute duration).

 

 

 

PGE Flange Gasket

The PGE Flange Gasket is a low-pressure service gasket designed for electrical flange isolation and/or general sealing applications. This gasket is suitable for use in raised-face and flat-face flanges in ANSI class 150 and 300 service (or equivalent). In addition to providing electrical insulation, the gasket is excellent for electrically isolating flanges made of dissimilar metals or where prevention of flange face corrosion is desired.

The PGE Flange Gasket was designed to give operators an alternative to ailure-prone phenolic-based insulating gaskets. Based on its construction, the PGE will provide a superior, long-lasting solution when compared to phenolic-based designs. The PGE is available in two configurations: full-face (Type E) and ring style (Type F). Depending upon the sealing element selected, the PGE is rated for most all hydrocarbon and water service applications.

The unique design of the Pikotek PGE gasket incorporates patented overlapping and offsetting seal grooves. The purpose of this design is to break each layer of laminate within the gasket itself, thereby creating a barrier through which fluid and/or gas cannot migrate. The sealing element can be any elastomeric material as well as more sophisticated Spring-Energized Teflon lip seals. As a result of this advanced gasket design, maintenance-free flange isolation and flange face corrosion mitigation are achieved economically.

Advantages & Benefits

  • Superior sealing solution for low-pressure (ANSI class 150 and 300) service.
  • Pressure-activated seals provide high confidence sealing.
  • High-strength laminate material resists failure due to excess compression (i.e., over-tightening bolts).
  • Overlapping seal grooves eliminate potential leak/weep path in laminate material and provide stronger structural integrity versus "opposing seal" designs.
  • Reinforced laminate retainer material provides excellent insulation for cathodic protection systems.
  • Insulating Kits always include high-strength double washers and full-length sleeves for maximum assurance against shorting.
  • Gasket is sized to the bore, which protects flange faces from media-induced corrosion and flow-induced erosion.
  • Mitigates galvanic corrosion in dissimilar metal flanges.
  • Developed from proven Pikotek sealing technology.
  • Spring-energized Teflon seal provides radial load and encapsulation in the seal groove, which eliminates cold flow. This seal truly distinguishes the PGE from all other sealing systems.
  • Also available with a variety of elastomeric seals.
  • Easy installation, make up and removal
    - The PGE 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 self-centering, quick to install; no special tools are required.
  • Maintenance-free, corrosion-resistant design.
PGE Design

Gasket/Seal Retainer

The PGE gasket/seal retainer is constructed from NEMA grade G-I0 glass-reinforced epoxy (GRE). This material has excellent performance characteristics with very high compressive strength, high flexural strength, high dielectric strength and low fluid absorption. PGE gaskets made from grade G- 10 material are rated for service up to 300 degrees F (150 C). For higher temperature service, grade G- I I is an acceptable alternative material, which is rated for 350 degrees F (177 C) continuous service.

Two overlapping and offsetting seal grooves are machined into the high strength retainer in order to break the potential leak/weep path that is inherent in all glass laminate materials. The breaking of the leak/weep path is unique to the PGE and truly distinguishes it from all other electrical insulating flange gaskets.

Sealing Elements

The sealing elements provide an impervious barrier through which no contained media or other substance can penetrate. Consequently, the composite retainer backing material behind the seal remains uncontaminated and thus permanently holds the seal in place in a static, fully-encapsulated manner.

Pikotek offers three standard sealing elements for use with the PGE. For custom applications, other sealing elements such as Kalrez or EPDM may be specified. The three standard seals are:

  • Teflon (Spring-energized)
    Recommended for all environments. Helical wound spring provides radial load. Encapsulation in the seal groove eliminates creep or cold flow. This sealing system truly distinguishes Pikotek gaskets from all other flange sealing systems. Teflon is the most reliable sealing element available.

      
  • Viton
    General purpose oilfield elastomer. Excellent resistance to aliphatic hydrocarbons and glycols. Good resistance to aromatic hydrocarbons. Not recommended for: Systems with amine inhibitors and in piping systems containing significant partial pressures of H
    2S, polar gases (i.e. C02) or where radical pressure drops commonly occur.
      
  • Nitrile
    General purpose elastomer. Excellent for use in water systems or with some aliphatic hydrocarbons, silicone base fluids and glycol based systems.
    Not recommended for: Systems containing H
    2S, aromatic hydrocarbons, phosphate esters or halogenated hydrocarbons; piping systems subjected to radical pressure drops or piping systems containing significant partial pressures of polar gases (i.e., C02).

Insulating Kits

In order to electrically insulate the two flange faces, insulating sleeves and washers are required. To protect your investment in flange isolation, Pikotek only provides full length sleeves and double washer sets (i.e. one insulating washer for each end of the bolt). All insulating washers are made of GRE and have a compressive strength of 60,000 psi. Two metal washers are also provided for each sleeve.

Pikotek offers insulating sleeves made from GRE and Mylar. The metal washers are either zinc plated 1050 carbon steel or stainless steel. Other custom materials are available on request.