POINTGUARD™ Gaskets

An engineering equal to the PSI LineBacker Sealing/Isolating Gasket


General Description

The POINTGUARD™ sealing/isolating gasket system is designed for general applications where electrical flange isolation and corrosion control are required on pipes containing water/wastewater, gas, natural gas, oil and other hydrocarbon based medias up to 302ºF(150ºC). Available for flat face, raised face and ring type joint flanges from 1/2" to 120" (and corresponding API and DN diameters), ANSI 150-1500#, API 2-5K or PN20-250, the POINTGUARD™ gasket is an engineered value added solution for trouble free operation. The POINTGUARD™ sealing/isolating gasket system consists of a retainer with an incline-plane seal groove geometry designed to optimize each seal's elastic memory, in conjunction with a proven rectangular sealing element ("Quad" ring). This design guarantees low bolt load requirements and high sealing reliability. POINTGUARD™ systems are available with a variety of retainers and seal elements.


A Fresh Look at Sealing - Design Features

A Fresh Look at Sealing - Design Feature: A non-spliced (one-piece) Teflon seal element, available from 1/2" to 24". Combining this seal with the incline-plane groove design is a first for this generation of gasket technology; an excellent choice for engineers and end users wanting increased seal integrity.



An engineering equal to the PSI LineBacker Sealing/Isolating Gasket Before Tightening
The flange face makes initial/light contact with the gasket retainer surface (isolation material) and the sealing element protrudes just above the gasket retainer surface.

An engineering equal to the PSI LineBacker Sealing/Isolating Gasket After Tightening
Rectangular Sealing Element "Quad Seal" in conjunction with the incline plane provides a self-energized seal. The small gap between seal element and retainer illustrates how the incline plane allows the seal material to move in a direction other than point loading the gasket web (small area of retainer between the two seals). This movement prevents cracking and breaking of the gasket retainer under high loads.
Furthermore, the incline plane groove provides the seal with greater elastic memory, thereby helping maintain an effective seal even when bolt load may relax over a period of time.


An engineering equal to the PSI LineBacker Sealing/Isolating Gasket


Retainer Materials (G10, G11, Phenolic)


Note: Consider G10 Material for the following applications. Nominal Pipe Sizes of 12-inch and larger or ANSI pressure class 600# and higher.


Gasket/Retainer Material Specifications

ASTM

TEST METHOD

G10

G11

Phenolic

D149

Dielectric Strength Volts/Mil Short Time

750-800

550

500

D695

Compressive Strength (psi)

65,000

63,000

25,000

D570

Water Absorption (%)

0.05

0.10

1.60

D790

Flexural Strength (psi)

65,000

60,000

22,500

D256

IZOD Impact Strength (Ft-lbs/Inch

14.0

12.0

1.20

D638

Tensile Strength (psi)

50,000

42,000

20,000

D732

Shear Strength (psi)

21,000

21,000

10,000

D952

Bond Strength (lb)

2,600

2,200

1,500

 

Temperature - Operating

Cryogenic -238°F (-150°C) to +302°F (+150°C)

-100°F (-73°C) to +392°F (+200°C)

+65°F (-54°C) to +220°F (+104°C)

NOTE: Operating Temperature for Gaskets and Flange Isolation Kits is based off the Gasket Retainer Temperature. Seal element temperature does not dictate the Min. and max. gasket operating temperature.


Seal Element Materials


Seal Element Material Specifications

Sealing Element

Temperature - Operating

Teflon®

Cryogenic to +525°F (+274°C)

Nitrile

-40°F (-40°C) to +250°F (+121°C)

Silicone

-75°F (-115°C) to +392°F (+200°C)

Viton®

-20°F (-29°C) to +392°F (+200°C)

EPDM

-65°F (-54°C) to +250°F (+121°C)


Configurations for Gasket Type and Sleeve and Washer Sets


Type "E" Gasket
Fits over the bolt holes and extends to the O.D. of the flange to assist contractors as the bolt holes automatically center the gasket. Provides excellent protection against shorting out of the corrosion mitigation hardware.


Type "F" Gasket Fits within the bolt hole circle of the flange and extends to the I.D. of the bolt circle providing good protection against shorting out of the corrosion mitigation hardware.

"E" or "F" Type Gaskets
The POINTGUARD gasket is available in a Type "E" or "F" configuration to accommodate all your sealing/isolating needs.


Single Washer Set
One isolation sleeve, one steel washer and one insulating washer for each stud/bolt.

Double Washer Set
One isolation sleeve, two steel washers and two insulating washers for each stud/bolt.


Suggested Sleeve/Washer Sets

SD = Standard (G10 Sleeves, Steel Zp Washers and G10 Washers) - Double Washer Set


ED = Economy (Mylar Sleeves, Steel ZP Washers and Phenolic Washers) - Double Washer Set