Materials used:
Stainless Steel, Nickel Alloy etc.

Specifications:

Tube OD sizes: 3/8 to 2 inches Materials:
Flange: 304 or 316L stainless steel
O-rings: Viton, Buna, & silicone
Fasteners: Wingnut, SureSeal,
bulkhead & EVAC clamps
Vacuum range
Elastomer seal: >=1 x 10^-8 Torr - High vacuum
EVAC metal seal: >=1 x 10^-11 Torr - UHV
Temperature range
Viton: -20°C to 200°C
Silicone: -50°C to 230°C
Buna: -30°C to 110°C
EVAC metal seal: -270°C to 150°C

Key Features:

This is the most common type of high pressure pipe flange. They are distinguished from other types of pipe flanges by their long tapered hub and gentle transition of thickness in the region of the butt weld joining them to the pipe. The long tapered hub provides an important reinforcement of the weld neck flange proper in terms of strength and resistance to dishing.

Uses of weld neck flanges:

• The weld neck flange is very resistant to dishing and has a very sturdy connection because it has the pipe along with the tapered hub.
• The flanges are ideal for extreme fluctuations of temperature.
• They are ideal in environments where there may be a lot of bending and handling of the flanges.
• Preferred in an environment with extreme temperature conditions.
• This type of flange is preferred for every severe service condition—resulting from high pressure or from sub-zero or elevated temperature.
• They are used in situations where loading conditions are substantially constant or fluctuate between wide limits.
• This is probably the best welding flange available because of its high, heavy neck.
• Highly recommended wherever a sound welded joint connection is needed.