1. Select the size:
For flat face flanges, raised face flanges, and manways:
Measure the width of the sealing surface and reference the table below to select the nominal width of GORE Joint Sealant.
|Effective Sealing Width||GORE Joint Sealant Nominal Width|
|3 - 7||1/8 - 1/4||3||1/8|
|7 - 10||1/4 - 3/8||5||3/16|
|10 - 17||3/8 - 5/8||7||1/4|
|17 - 25||5/8 - 1||10||3/8|
|25 - 40||1 - 1.5||14||1/2|
|40 - 50||1.5 - 2||17||5/8|
|50 - 65||2 - 2.5||20||3/4|
For tongue and groove flanges:
Select the nominal width of GORE® Joint Sealant that is equal to or less than the width of the groove.
ATTENTION: Perform an engineering torque estimation to confirm a gasket stress higher than
17 MPa (2500 psi) can be achieved.
2. Determine a Torque Value
- Typical minimum stress to seal values for GORE Joint Sealant are:
- y-factor = 17 MPa (2500 psi)
- Qmin L0.1 = 21 MPa (3045 psi)
There are two methods of calculating the required force.
Method 1: Compressed Width Factor
The gasket area can be calculated by multiplying the length by 1.5 the nominal width of the joint sealant applied in your application. 1.5 is a conservative factor. If you'd like to assess your application in more accurate detail, use the table to select the compressed width factor or the Line Force Method described below.
F = σgasket · Factor · Wnominal · Lgasket
F= Total Force
σgasket = To be applied Gasket Stress
Factor = Compressed Width Factor
Wnominal = Nominal Width
Lgasket = Length of Joint Sealant
Method 2: Line Force
Gore conducted tests and utilized analytical techniques to determine the amount of force required to compress a unit length of joint sealant. This force to compress one unit length of material is called Line Force. The line force is independent of compressed gasket width.
F = Fline · Lgasket
F = Total Force
Fline = Line Force at desired gasket stress for a given Nominal Width
Lgasket = Length of Joint Sealant
Perform an engineering calculation to determine the torque value for your specific application. Industry guidance is available, for example in ASME PCC-1 Guidelines for Pressure Boundary Bolted Flange Joint Assembly, and EN 1591-1 Flanges and their Joints - Design Rules for Gasketed Circular Flange Connections - Part 1: Calculation.
3. Install the Joint Sealant
A. Prepare the Flange
- Open the flanges a minimum of 15 cm (6").
- Completely clean the surface to ensure optimal adhesion. Remove all oil, graphite, and other residue.
B. Apply Joint Sealant
Remove the adhesive backing a little at a time, to prevent the adhesive strip from picking up dirt. Position the end of the joint sealant around the starting bolt hole.
ATTENTION: In cold conditions, gently warm the joint sealant before installation to make the adhesive more sticky.
C. Complete Joint Sealant Gasket
Complete the gasket by overlapping both ends at the starting bolt hole and cut away excess material. See illustrations.
ATTENTION: In some joint sealant applications the skive cut overlap technique must be used because the flange cannot withstand enough force to compress the double thickness of gasket material at an overlap joint. This is possibly the case when using joint sealant with a nominal width >17mm (5/8"), except when installed on ASME or JIS metallic flanges. If uncertain, the skive cut technique can always be used as an alternative to the overlap technique.
Skive Cut Technique - An Alternate Method of Completing the Joint Sealant Gasket
a. Inititial Skive Cut
Unwind about 0.5 m (1.5 ft) of GORE® Joint Sealant.
Cut the end with a sharp knife on a clean, firm surface using the skiving technique.
In general, the length of the skive cut, ls, should be approximately 25 mm (1").
b. Closing Skive Cut
- Complete the gasket by laying the Joint Sealant over the skived end, extending beyond ≈ 14 mm (1/2").
- To prepare for the second and final skive cut, identify and mark the starting and end points.
- Cut away the gasket material at an angle. This will leave an area of ≈ 120% (h) of the original gasket thickness.
4. Review and Follow Standard Bolted Flange Assembly Practices
GORE® Gasketing Products do not require special assembly practices. However, ulitizing Industry Best Practices is always recommended when assembling a bolted flanged joint. Such practices have been developed by ASME, European Sealing Association (ESA), Fluid Sealing Association (FSA) and the Association of German Engineers (VDI) .
- ESA/FSA Gasket Installation Procedures Assuring Joint Integrity and Maximum Safety
- ASME PCC-1 Guidelines for Pressure Boundary Bolted Flange Joint Assembly
- VDI 2200 - Tight flange connections: Selection, calculation, design and assembly of bolted flange connections
- ASME also offers training classes on bolted flange joint assembly
- Multiple organizations also offer EN 1591-4 specified training content for bolted flange joint assembly
Ensure the sealing surfaces are clean, dry, and free of grease.
Position the gasket so that it is centered on the flange (use the bolts as a guide).
Lubricate the fasteners well. Be sure to lubricate all load bearing surfaces on the bolts, nuts, and washers.
Assemble bolts, washers and nuts on the flange.
Finger-tighten the bolts, moving in a circular direction.
Utilize a calibrated torque device to torque each bolt in a star pattern sequence. Apply the torque in three passes:
- 1st Pass: 30% of Target Torque
- 2nd Pass: 60% of Target Torque
- 3rd Pass: 100% of Target Torque
Apply the torque at 100% of Target Torque in a circular pass. Then wait 4 hours.
Complete the installation by performing circular passes until all bolts have acheived the target torque.
FOR INDUSTRIAL USE ONLY
Not for use in food, drug, cosmetic or medical device manufacturing, processing, or packaging operations.