ASTM A516 Gr. 65 Gr.70 ASME B16.48 Spectacle Blind Flange

1、What Is Spectacle Blind Or Figure 8 Blind?

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.

2、Spectacle Blind Flange Class & Types & Specification

Dimensions : ASME B16.48

Material: ASTM A516N GR.70

Size :1/2″ (15 NB) to 48″ (1200NB)

Class :150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS, DIN Standard ND-6,10, 16, 25, 40 Etc.

DIN : DIN2527, DIN2566, DIN2573, DIN2576, DIN2641, DIN2642, DIN2655, DIN2656, DIN2627, DIN2628, DIN2629, DIN 2631, DIN2632, DIN2633, DIN2634, DIN2635, DIN2636,DIN2637, DIN2638, DIN2673

BS : BS4504 , BS4504, BS1560, BS10

Flange Face Type : Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)

ASME SA 516 GR 70 SPADE PADDLE BLIND ASME B16.48

DIMENSIONS SPECTACLE BLINDS ASME B16.48

NPS	Outside Ø A	Inside Ø B	Center Line C	THK t	Web Width W
1/2	45	16	60	3	38
3/4	54	21	70	3	38
1	64	27	80	3	38
1.1/4	73	42	90	6.4	38
1.1/2	83	48	100	6.4	38
2	102	61	120	6.4	51
2.1/2	107	73	140	6.4	51
3	133	89	150	6.4	64
3.1/2	159	102	175	9.7	64
4	172	114	190	9.7	64
5	194	141	215	9.7	76
6	219	168	240	12.7	76
8	276	219	300	12.7	76
10	337	273	360	15.7	102
12	406	324	430	19.1	102
14	448	356	475	19.1	108
16	511	406	460	22.4	108
18	546	457	580	25.4	114
20	603	508	635	28.4	121
24	714	610	750	31.8	140

ASME SA 516 GR 60 SPADE PADDLE BLIND ASME B16.48

Dimensions of Spades and Ring Spacers ASME B16.48

Pressure Class 150

NPS	Outside Dia A	Inside Dia B	Center End C	Thick ness t	Handle Width W
1/2	45	16	126	3	32
3/4	54	21	131	3	32
1	64	27	136	3	32
1.1/4	73	42	145	6.4	32
1.1/2	83	48	145	6.4	32
2	102	61	155	6.4	32
2.1/2	107	73	170	6.4	32
3	133	89	170	6.4	32
3.1/2	159	102	202	9.7	38
4	172	114	202	9.7	38
5	194	141	225	9.7	38
6	219	168	225	12.7	38
8	276	219	267	12.7	38
10	337	273	322	15.7	44
12	406	324	357	19.1	44
14	448	356	378	19.1	44
16	511	406	410	22.4	44
18	546	457	427	25.4	51
20	603	508	455	28.4	51
24	714	610	512	31.8	51

Pressure Class 300

NPS	Outside Dia A	Inside Dia B	Center End C	Thick ness t	Handle Width W
1/2	51	16	129	6.4	32
3/4	64	21	136	6.4	32
1	70	27	139	6.4	32
1.1/4	79	42	150	6.4	32
1.1/2	92	48	150	6.4	32
2	108	61	158	9.7	32
2.1/2	127	73	177	9.7	32
3	146	89	177	9.7	32
3.1/2	162	102	205	12.7	38
4	178	114	205	12.7	38
5	213	141	240	15.7	38
6	248	168	240	15.7	38
8	305	219	281	22.4	38
10	359	273	333	25.4	44
12	419	324	363	28.4	44
14	483	356	395	31.8	44
16	536	406	422	38.1	44
18	594	457	450	41.1	51
20	651	508	480	44.5	51
24	772	610	540	50.8	51

Pressure Class 600

NPS	Outside Dia A	Inside Dia B	Center End C	Thick ness t	Handle Width W
1/2	51	16	129	6.4	32
3/4	64	21	136	6.4	32
1	70	27	139	6.4	32
1.1/4	79	37	150	9.7	32
1.1/2	92	43	150	9.7	32
2	108	55	158	9.7	32
2.1/2	127	67	177	12.7	32
3	146	83	177	12.7	32
3.1/2	159	96	211	15.7	38
4	191	108	211	15.7	38
5	238	135	248	19.1	38
6	264	162	248	22.4	38
8	318	212	288	28.4	38
10	397	265	352	35.1	44
12	454	315	381	41.1	44
14	489	346	398	44.5	44
16	562	397	435	50.8	44
18	610	448	459	53.8	51
20	679	497	493	63.5	51
24	787	597	547	73.2	51

Pressure Class 900

NPS	Outside Dia A	Inside Dia B	Center End C	Thick ness t	Handle Width W
1/2	60	16	134	6.4	32
3/4	67	21	137	6.4	32
1	76	27	142	6.4	32
1.1/4	86	37	151	9.7	32
1.1/2	95	43	151	9.7	32
2	140	55	174	12.7	32
2.1/2	162	67	186	12.7	32
3	165	83	186	15.7	32
4	203	108	217	19.1	38
5	244	135	259	22.4	38
6	286	162	259	25.4	38
8	356	212	307	35.1	38
10	432	265	370	41.1	44
12	495	315	401	47.8	44
14	518	346	412	53.8	44
16	572	397	440	60.5	44
18	635	448	471	66.5	51
20	696	497	501	73.2	51
24	835	597	571	88.9	51

Pressure Class 1500

NPS	Outside Dia A	Inside Dia B	Center End C	Thick ness t	Handle Width W
1/2	61	16	135	6.4	32
3/4	67	21	137	9.7	32
1	76	27	142	9.7	32
1.1/4	86	35	151	9.7	32
1.1/2	95	41	151	12.7	32
2	140	53	174	12.7	32
2.1/2	162	63	190	15.7	32
3	172	78	190	19.1	32
4	206	102	219	22.4	38
5	251	128	256	28.4	38
6	279	154	256	35.1	38
8	349	203	303	41.1	38
10	432	255	370	50.8	44
12	518	303	412	60.5	44
14	575	333	442	66.5	44
16	638	381	472	76.2	44
18	702	429	504	85.9	51
20	752	478	530	95.3	51
24	899	575	603	111.3	51

Pressure Class 2500

NPS	Outside Dia A	Inside Dia B	Center End C	Thick ness t	Handle Width W
1/2	67	16	137	9.7	32
3/4	73	21	140	9.7	32
1	83	27	145	9.7	32
1.1/4	102	35	161	12.7	32
1.1/2	114	41	161	15.7	32
2	143	53	175	15.7	32
2.1/2	165	63	201	19.1	32
3	194	78	201	22.4	32
4	232	102	232	28.4	38
5	276	128	273	35.1	38
6	314	154	273	41.1	38
8	384	198	321	53.8	38
10	473	248	390	66.5	44
12	546	289	427	79.2	44

Dimensions are in millimeters unless otherwise indicated.
Spade Handles shall be solid with NO openings.

Further notes：

Ring Spacer Handles shall have a single through indicator hole located near the end of the handle. The hole diameter shall not be less than 12 mm.
Wt = Thickness of the handle should be 6 mm minimum, or equal to Thickness (t) if less than 6 mm.
Spades and Ring Spacers should be made from a plate or forging specification, approved for use by ASME B31.3, of essentially the same chemical composition as the mating flanges and piping involved.
Spades and Ring Spacers ASME B16.48 may be used for installation between ASME B16.5 flanges
Depending on a customer specification, some dimensions can be different from what on this page is defined.

3、Use Of Spectacle Blind, Spades And Spacers

Spectacle Blind, Spades and Spacers are used to provide flexibility during maintenance an operation. Therefore, it is essential to consider this during design of Piping system. Blanks are installed in horizontal line. In general, you can see the use of spectacle blind flange at following location;

At inlets and outlets of static equipment
At inlets and outlets of rotary equipment
At inlets and outlets of fired heater and common headers
In bypass line
At unit battery limit

4、Spec Blinds Are Available In The Following Face Type

Raised Face
Female Ring-Joint Blanks
Male Ring-Joint Blanks

5、Chemical Composition %

Ni	Mo	Cr	Fe	W	Co	Mn	C
Remainder	15.0-17.0	14.5-16.5	4.0-7.0	3.0-4.5	2.5 max	1.0 max	.01 max
V	P	S	Si
.35 max	.04 max	.03 max	.08 max

6、Mechanical Properties

Product Form	Tensile (ksi)	.2% Yield (ksi)	Elongation %
Bar	110.0	52.6	62
Plate	107.4	50.3	67
Sheet	115.5	54.6	60
Tube & Pipe	105.4	45.4	70

Our aim is to delight customers with top-notch service, competitive pricing, and high-quality ASTM A516 Gr. 65 Gr. 70 ASME B16.48 Spectacle Blind Flanges. Thanks to our professional teamwork, we’ve secured numerous long-term overseas clients. We eagerly await the opportunity to serve you as your trusted partner!

Blind Flange/

1、What Is Spectacle Blind Or Figure 8 Blind?