A516 Grade 70 Spectacle Blind Flange,ASME B16.48 A516 Grade 60 SPECTACLE BLIND FLANGES

We can manufacture A516 Grade 70 Spectacle Blind Flange,ASME B16.48 A516 Grade 60 SPECTACLE BLIND FLANGES with different type of joint face (RF, FF, RTJ) in series 150/300/600/900/1500/2500 in according to major dimensional standards ASME B16.48

A516 Gr.60,A516 Gr 70 Spectacle blind Flanges Figure 8 flange

Figure-8 Blanks, Spectacle Flange

spectacle blind Flange ,also known as figure 8 Flange which is combination of the two that can be rotated to function as Single Bind or a Ring Spacer. This kind of flange is generally a piece of metal than is cut to fit between two pipe flanges and usually sandwiched between two gaskets a spectacle blind is often made from two metal discs that are attached to each other by a small section of steel. The Sharp is similar to a pair of glasses or spectacles – hence the name spectacle blind flange. One end of the blind will have an opening to allow flow through the pipe during operation and the other end is solid to block flow during maintenance. They are generally installed as a permanent device to separate process piping system.

The whole idea of a spectacle blind Flange is so that one can be absolutely sure that an item of equipment is properly and securely blanked off with no possibility of any flow or leakage through a valve during maintenance. The flow can be diverted to other items of equipment but not just by passed around the blank as this would compromise the safety function of the spectacle blind. The flow has to valve off and pressure relieved prior to loosening flange bolts and swinging the blind.

 Spectacle Blind Flange may have a different type of joint face (RF Raised Face, FF Flat Face, RTJ Ring Joint), depending the type of flange

Spectacle Blind Flange  is usually used on the oil line with two different functions:

  • If the spade is put in between the flanges, it stops the fluid’s passage;
  • If the spacer is put in between the flanges, the passage of the fluid is allowed.

The Spectacle Blind is inserted between two flanges: in order to guarantee a perfect  waterlight two gaskets are normally mounted , one on each side of spectacle blind.

ASTM A516 GR.60 CHEMICAL COMPOSITION

C Si Mn P S Al Cr Cu Ni Mo Nb Ti V
0.18 0.4 0.95/1.50 0.015 0.008 0.02 (Min) 0.3 0.3 0.3 0.08 0.01 0.03 0.02

ASTM A516 GR.60 PLATES MECHANICAL PROPERTIES

Tensile strength (ksi) Yield strength (ksi) Elongation min, % 200 mm (8 in) Elongation min, % 50 mm (2 in)
485-620 (70-90) 260 (38) 17 21

 

ASME/ANSI B16.48 Class 150 Spectacle Blind Flange / Figure-8 Blank RF

How to order our  A516 Gr70 Spectacle Blind Flanges?

Size: 3 Inch

Pressure: 150#

Seal Type: RF

Standard: ASME B16.5