Bolted Line Blinds

 

Similar to standard line unions, the Bolted Line Blind is a labor-saving positive-seal means of opening and closing process lines. Frequently found in petrochemical and cement plants, bulk loading and storage terminals, LPG and LNG gathering systems, marine facilities, steel mills, and food processing facilities, Bolted Line Blinds are an economical solution to positive flow and positive shut-off.

Three equally-spaced spreader bolts separate the flanges to free the figure-8 spectacle plate. Reverse the self-centering spectacle to the open position for a full bore flow connection with metal-to-metal seat and secondary O-ring seal. Re-tighten the spreader bolts to restore a leak-proof connection. O-ring grooves in the spectacle enable easy replacement of the seals. Stainless helicoils insure longer thread life and greater strength. Line status is clearly visible from a distance.

Standard blinds are available in carbon steel with butt-weld end connections with Viton seals. Pressure classes include 150 or 300 in either schedule 40, 80 or 160. Special materials, end connections or seals are available on request.

Greenwood Valve Catalog

 

Bolted Line Blinds

Parts

No. Req. Part Material
1 1 Threaded Flange A105 C.S.
2 1 Slotted Flange A105 C.S.
3 1 Spectacle Zinc Plated Carbon Steel
4 4 O-Rings Viton or Teflon
5 3 Bolts 4140 HT Steel
6 2 Centering Pins Carbon Steel
7 3 Helicoils Stainless Steel

 

Bolted Line Blinds Drawing
Dimensions

150 lbs.
300 lbs.  
Sizes
A
B
C
A
B
C
1/2
4 1/8
3
3 1/2
4 1/2
3
3 3/4
3/4
4 1/2
3 3/4
3 7/8
4 7/8
3 3/4
4 5/8
1
4 3/4
4 5/8
4 1/4
5 1/4
4 5/8
4 7/8
1 1/2
5 3/8
5 5/8
5
5 7/8
5 5/8
6 1/8
2
5 1/2
7 1/8
6
6 1/8
7 3/8
6 1/2
3
6
8 3/4
7 1/2
6 7/8
8 3/4
8 1/4
4
6 9/16
10 3/4
9
7 1/32
10 3/4
10
5
7 3/4
12 1/4
10
8 5/8
14
11
6
7 3/4
13 3/4
11
8 3/4
14
11
8
8 3/4
17 1/4
13 1/2
9 3/4
11 1/4
15
10
9
25 1/4
16
10 3/8
20 1/2
17 1/2
12
10 3/8
-
19
11 3/4
25
20 1/2
14
11
-
21
12 7/8
-
23
16
11 1/8
-
23 1/2
13 1/4
-
25 1/2
18
12 1/2
-
25
14 3/8
-
28
20
13
-
27 1/2
14 3/4
-
30 1/2