Spectacle Blind Raised Face

Type: 304L Spectacle Blind Flange
Size: DN50 (2″)
Class Rate: 300#
Material: 304L (UNS S30403/1.4307)
Standard: ASME B16.48

ASME B16.48 A182 F304L Spectacle Blind Flange Raised Face, 2″, CL300.

Chemical Composition and Mechanical Property for 304/304L
Steel Grade	Chemical Composition									Mechanical Performance
	C(Max)	Si(Max)	Mn(Max)	P(Max)	S(Max)	Ni	Cr	N	Mo	Tensile Strength (Min)	Yield Strength (Min)
										Mpa	Mpa
304	0.08	0.75	2.00	0.045	0.03	8.0–10.5	18.0–20.0	0.1	/	515	205
304L	0.03	0.75	2.00	0.045	0.03	8.0–12.0	18.0–20.0	0.1	/	485	170

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.

Technical drawing for the figure-8 blank (spectacle blind flange) in accordance with ASME B16.48, with raised face. The RF dimensions shall be furnished in accordance with ASME B16.5. The height of the raised face shall be in addition to the thickness T. For Class 150 & 300, the height of RF shall be 2 mm; for Class 600, 900, 1500 & 2500, the height of RF shall be 7 mm.

Dimensions & Weights

NPS	O	A	T	W	B
1/2	45	60	3.0	38	16
3/4	54	70	3.0	38	21
1	64	80	3.0	38	27
1-1/4	73	90	6.4	38	42
1-1/2	83	100	6.4	38	48
2	102	120	6.4	51	61
2-1/2	107	140	6.4	51	73
3	133	150	6.4	64	89
3-1/2	159	175	9.7	64	102
4	172	190	9.7	64	114
5	194	215	9.7	76	141
6	219	240	12.7	76	168
8	276	300	12.7	76	219
10	337	360	15.7	102	273
12	406	430	19.1	102	324
14	448	475	19.1	108	356
16	511	540	22.4	108	406
18	546	580	25.4	114	457
20	603	635	28.4	121	508
24	714	750	31.8	140	610

* Basic dimensions for ASME B16.48 Class 150 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS	O	A	T	W	B
1/2	51	65	6.4	38	16
3/4	64	80	6.4	38	21
1	70	90	6.4	57	27
1-1/4	79	100	9.7	57	37
1-1/2	92	115	9.7	67	43
2	108	125	9.7	57	55
2-1/2	127	150	12.7	67	67
3	146	170	12.7	67	83
3-1/2	159	185	15.7	76	96
4	191	215	15.7	76	108
5	238	265	19.1	86	135
6	264	290	22.4	86	162
8	318	350	28.4	95	212
10	397	430	35.1	105	265
12	454	490	41.1	105	315
14	489	525	44.5	114	346
16	562	605	50.8	124	397
18	610	655	53.8	133	448
20	679	725	63.5	133	497
24	787	840	73.2	152	597

* Basic dimensions for ASME B16.48 Class 300 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS	O	A	T	W	B
1/2	51	65	6.4	38	16
3/4	64	80	6.4	38	21
1	70	90	6.4	57	27
1-1/4	79	100	9.7	57	37
1-1/2	92	115	9.7	67	43
2	108	125	9.7	57	55
2-1/2	127	150	12.7	67	67
3	146	170	12.7	67	83
3-1/2	159	185	15.7	76	96
4	191	215	15.7	76	108
5	238	265	19.1	86	135
6	264	290	22.4	86	162
8	318	350	28.4	95	212
10	397	430	35.1	105	265
12	454	490	41.1	105	315
14	489	525	44.5	114	346
16	562	605	50.8	124	397
18	610	655	53.8	133	448
20	679	725	63.5	133	497
24	787	840	73.2	152	597

* Basic dimensions for ASME B16.48 Class 600 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS	O	A	T	W	B
1/2	60	80	6.4	38	16
3/4	67	90	6.4	41	21
1	76	100	6.4	57	27
1-1/4	86	110	9.7	57	37
1-1/2	95	125	9.7	67	43
2	140	165	12.7	57	55
2-1/2	162	190	12.7	67	67
3	165	190	15.7	67	83
4	203	235	19.1	76	108
5	244	280	22.4	86	135
6	286	320	25.4	86	162
8	356	395	35.1	95	212
10	432	470	41.1	105	265
12	495	535	47.8	105	315
14	518	560	53.8	114	346
16	572	615	60.5	124	397
18	635	685	66.5	133	448
20	696	750	73.2	133	497
24	835	900	88.9	152	597

* Basic dimensions for ASME B16.48 Class 900 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS	O	A	T	W	B
1/2	61	80	6.4	38	16
3/4	67	90	9.7	41	21
1	76	100	9.7	64	27
1-1/4	86	110	9.7	64	35
1-1/2	95	125	12.7	70	41
2	140	165	12.7	70	53
2-1/2	162	190	15.7	76	63
3	172	205	19.1	76	78
4	206	240	22.4	89	102
5	251	290	28.4	89	128
6	279	320	35.1	89	154
8	349	395	41.1	102	203
10	432	480	50.8	114	255
12	518	570	60.5	114	303
14	575	635	66.5	127	333
16	638	705	76.2	133	381
18	702	775	85.9	146	429
20	752	830	95.3	152	478
24	899	990	111.3	178	575

* Basic dimensions for ASME B16.48 Class 1500 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS	O	A	T	W	B
1/2	67	90	9.7	38	16
3/4	73	95	9.7	41	21
1	83	110	9.7	64	27
1-1/4	102	130	12.7	64	35
1-1/2	114	145	15.7	70	41
2	143	170	15.7	70	53
2-1/2	165	195	19.1	76	63
3	194	230	22.4	76	78
4	232	275	28.4	89	102
5	276	325	35.1	89	128
6	314	370	41.1	89	154
8	384	440	53.8	102	198
10	473	540	66.5	114	248
12	546	620	79.2	114	289

* Basic dimensions for ASME B16.48 Class 2500 figure-8 blanks (spectacle blind flanges) with FF or RF.

NPS	900#	1500#	2500#
1/2	0.46	0.46	0.72
3/4	0.61	0.79	0.89
1	0.80	1.05	1.19
1-1/4	1.37	1.40	2.14
1-1/2	1.73	2.08	3.17
2	3.98	4.04	4.90
2-1/2	5.21	6.21	7.50
3	6.68	8.47	11.81
4	11.45	13.58	20.45
5	18.15	23.62	34.01
6	27.04	34.45	49.98
8	53.48	60.13	94.12
10	88.31	108.77	171.27
12	130.89	182.62	268.26
14	156.56	245.28	–
16	208.72	339.62	–
18	278.80	457.52	–
20	361.74	569.25	–
24	619.04	936.93	–

* Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 150, 300 & 600.

NPS	900#	1500#	2500#
1/2	0.46	0.46	0.72
3/4	0.61	0.79	0.89
1	0.80	1.05	1.19
1-1/4	1.37	1.40	2.14
1-1/2	1.73	2.08	3.17
2	3.98	4.04	4.90
2-1/2	5.21	6.21	7.50
3	6.68	8.47	11.81
4	11.45	13.58	20.45
5	18.15	23.62	34.01
6	27.04	34.45	49.98
8	53.48	60.13	94.12
10	88.31	108.77	171.27
12	130.89	182.62	268.26
14	156.56	245.28	–
16	208.72	339.62	–
18	278.80	457.52	–
20	361.74	569.25	–
24	619.04	936.93	–

* Weights for spectacle blinds in sizes NPS 1/2″ through 24″ of Class 900, 1500 & 2500.

Menu

Search

Dimensions & Weights

Customers reviews

Join our newsletter