Industrial Data

Given Below are the graphs, which can be an easy guide for the selection of the valve pressure class suitable for a particular given temperature and pressure for the most commonly used materials- cost carbon steel (ASTMA 216 Gr.WCB) and SS-316 (ASTMA 351 Gr. CF8M).

Service Temperature		Class 150					Class 300					Class 600
Deg. F	Deg. C	WCB(a)	WC1(b)(c)	WC6(c)(d)	WC9(c)(d)	C5(c)	WCB(a)	WC1(b)(c)	WC6(c)(d)	WC9(c)(d)	C5(c)	WCB(a)	WC1(b)(c)	WC6(c)(d)	WC9(c)	C5(c)
-20 to	-29 to
100	38	285	365	290	290	290	740	695	750	750	750	1480	1395	1500	1500	1500
200	93	260	255	260	260	260	680	660	750	750	750	1360	1320	1500	1500	1500
300	149	230	230	230	230	230	655	640	720	730	730	1310	1275	1445	1455	1455
400	204	200	200	200	200	200	635	645	695	705	705	1265	1230	1385	1410	1410
500	260	170	170	170	170	170	605	585	665	665	665	1205	1175	1330	1330	1330
600	316	140	140	140	140	140	570	550	605	605	605	1135	1105	1210	1210	1210
650	343	125	125	125	125	125	550	535	590	590	590	1100	1065	1175	1175	1175
700	371	110	110	110	110	110	530	510	570	570	570	1060	1025	1135	1135	1135
750	399	95	95	95	95	95	505	475	530	530	530	1015	955	1065	1065	1065
800	427	80	80	80	80	80	410	390	510	510	510	825	780	1015	1015	1015
850	454	65	65	65	65	65	320	300	485	485	485	640	595	975	975	975
900	482	50	50	50	50	50	230	200	450	450	375	460	405	900	900	745
950	510	35	35	35	35	35	135	135	320	385	275	275	275	640	755	550
1000	538	20	20	20	20	20	85	85	215	265	200	170	170	430	535	400
1050	566			20	20	20			145	175	145			290	350	290
1100	593			20	20	20			95	110	100			190	220	200
1150	621			20	20	20			65	70	60			130	135	125
1200	649			15	15	15			40	40	35			80	80	70

Service Temperature		Class 900					Class 1500					Class 2500
Deg. F	Deg. C	WCB(a)	WC1(b)(c)	WC6(c)(d)	WC9(c)(d)	C5(c)	WCB(a)	WC1(b)(c)	WC6(c)(d)	WC9(c)(d)	C5(c)	WCB(a)	WC1(b)(c)	WC6(c)(d)	WC9(c)(d)	C5(c)
-20 to	-29 to
100	38	2220	2090	2250	2250	2250	3705	3480	3750	3750	3750	6170	5805	6250	6250	6250
200	93	2035	1980	2250	2250	2250	3395	3300	3750	3750	3750	5655	5505	6250	6250	6250
300	149	1965	1915	2165	2185	2185	3270	3190	3610	3640	3640	5450	5315	6015	6070	6070
400	204	1900	1845	2080	2115	2115	3170	3075	3465	3530	3530	5280	5125	5775	5880	5880
500	260	1810	1760	1995	1995	1995	3015	2930	3325	3325	3325	5025	4885	5540	5540	5540
600	316	1705	1655	1815	1815	1815	2840	2755	3025	3025	3025	4730	4595	5040	5040	5040
650	343	1650	1600	1765	1765	1765	2745	2665	2940	2940	2940	4575	4440	4905	4905	4905
700	371	1590	1535	1705	1705	1705	2665	2560	2840	2840	2840	4425	4270	4730	4730	4730
750	399	1520	1430	1595	1595	1595	2535	2385	2660	2660	2660	4230	3970	4430	4430	4430
800	427	1235	1175	1525	1525	1525	2055	1955	2540	2540	2540	3430	3255	4230	4230	4230
850	454	955	895	1460	1460	1460	1595	1490	2435	2435	2435	2655	2485	4060	4060	4060
900	482	690	605	1350	1350	1120	1150	1010	2245	2245	1870	1915	1685	3745	3745	3115
950	510	410	410	955	1160	825	685	685	1595	1930	1370	1145	1145	2655	3220	2285
1000	538	255	650	650	800	595	430	430	1080	1135	995	715	715	1800	2230	1655
1050	566			430	525	430			720	875	720			1200	1455	1200
1100	593			290	330	300			480	550	495			800	915	830
1150	621			195	205	185			325	345	310			545	570	515
1200	649			125	125	105			205	205	170			345	145	285

Note: (a) Permissible, but not recommended for prolonged usage above 800°F. Upon prolonged exposure to temperatures above 800°F, the carbide phase of Carbon Steel may be converted to Graphite.

(b) Permissible, but not recommended for prolonged usage above 875°F.

(c) Use normalized and tempered material only.

(d) Not to be used over 1100°F.

(e) For welded and valved only. Flanged end ratings terminate at 1,000°F, for WC6, WC9, & C5 materials.

(f) 1 psi = 0.070 kg./Sq. cm.

ASME B 16.34

Maximum Allowable Non-Shock Pressure in psig

Service Temperature		Class 150		Class 300		Class 600
Deg. F	Deg. C	CF8(1)	CF8M(1)	CF8(1)	CF8M(1)	CF8(1)	CF8M(1)
-20 to	-29 to	psig	psig	psig	psig	psig	psig
100	38	275	275	720	720	1440	1440
200	93	230	235	600	620	1200	1240
300	149	205	215	540	560	1075	1120
400	204	190	195	495	515	995	1025
500	260	170	170	465	480	930	955
600	316	140	140	440	450	885	900
650	343	125	125	430	440	865	885
700	371	110	110	420	435	845	870
750	399	95	95	415	425	825	855
800	427	80	80	405	420	810	845
850	454	65	65	395	420	790	835
900	482	50	50	390	415	780	830
950	510	35	35	380	385	765	775
1000	538	20	20	355	365	710	725
1050	566	20	20	325	360	650	720
1100	593	20	20	255	305	515	610
1150	621	20	20	205	235	410	475
1200	649	20	20	165	185	330	370
1250	677	20	20	135	145	26	295
1300	704	20	20	115	115	225	235
1350	752	20	20	95	95	185	190
1400	760	20	20	75	75	150	150
1450	788	20	20	60	60	115	115
1500	816	15	15	40	40	85	85

Service Temperature		Class 900		Class 1500		Class 2500
Deg. F	Deg. C	CF8(1)	CF8M(1)	CF8(1)	CF8M(1)	CF8(1)	CF8M(1)
-20 to	-29 to	psig	psig	psig	psig	psig	psig
100	38	2160	2160	3600	3600	6000	6000
200	93	1800	1860	3000	3095	5000	5160
300	149	1615	1680	2690	2795	4480	4660
400	204	1490	1540	2485	2570	4140	4280
500	260	1395	1435	2330	2390	3880	3980
600	316	1325	1355	2210	2255	3680	3760
650	343	1295	1325	2160	2210	3600	3680
700	371	1265	1305	2110	2170	3520	3620
750	399	1240	1280	2065	2135	3440	3560
800	427	1215	1265	2030	2110	3380	3520
850	454	1190	1255	1980	2090	3300	3480
900	482	1165	1245	1945	2075	3240	3460
950	510	1145	1160	1910	1930	3180	3220
1000	538	1065	1090	1770	1820	2950	3030
1050	566	975	1080	1630	1800	2715	3000
1100	593	770	915	1285	1525	2145	2545
1150	621	615	710	1030	1185	1715	1970
1200	649	495	555	825	925	1370	1545
1250	677	400	440	670	735	1115	1230
1300	704	340	350	656	585	945	970
1350	752	280	290	465	480	770	800
1400	760	225	225	380	380	630	630
1450	788	175	175	290	290	485	485
1500	816	125	125	205	205	345	345

API 6D

Bore (INCHES)	Classes
Bore (INCHES)	150	300	600	900	1500	2500
2	420	420	400	330	330	250
2 1 / 2	690	690	610	520	510	320
3 X 2	200	200	200	190	180	200
3	1200	1050	1000	910	820	500
4 X 3	600	600	600	590	550	560
4	2200	2100	1850	1800	1700	1100
6 X 4	800	800	790	790	780	745
6	5150	5100	4600	4380	3800	2500
8 X 6	2150	2150	2150	2150	2150	2150
8	9500	9400	9000	8500	7400	5300
10 X 8	4300	4300	4450	4450	4100	4100
10	15000	15000	14700	14500	11500	8300
12 X 10	7550	7550	7550	8000	9000	7550
14 X 10	6000	6000	6000	6100	6100
12	23000	23000	22500	21100	18000	13000
14 X 12	14000	14000	14000	12800	13000
16 X 12	9100	9100	9100	8900	8900
14	28000	28000	28000	25000	21000
16 X 14	15000	15000	15000	14200	14100
16	37200	37200	37200	34500	27500
18	21000	21000	21000	19200	19000

Data for Calculation of Flow

The coefficient of flow Cv expresses the rate of flow in gallons per minute at 60°F water with a pressure drop of 1 psig across the valve.The Cv coefficients for the various types and sizes shown in the tables, have been determined from actual flow tests.

Note: K_v is the metric equivalent of C_v.

K_V = C_V x 0.85

For Liquids:

Where Q_L = Flow in U.S. gallons per minute.
Δ P = (P1–P2) Pressure drop in psi.
G_L = Specific gravity of liquid (water = 1 at 60°F).

For Gases:

Where Q_g = Volumetric flow of gas (SCFH).
G_g = Specific gravity of gas at standard conditions.
(air at atmosphere and 60°F = 1)
T = Absolute temperature of gas
(°F + 460).

Note: For gas, max. ΔP = 1⁄2 P1, and min.
P2 = 1⁄2 P1, and P1, P2 are absolute pressures (psia)

PRESSURE RATING			150#		300#		600#		800#		900#		1500#		2500#
MATERIAL			150#		300#		600#		800#		900#		1500#		2500#
GrpNo.	Forging	Casting	Shell	S/B	Shell	S/B	Shell	S/B	Shell	S/B	Shell	S/B	Shell	S/B	Shell	S/B
GrpNo.	Forging	Casting	kg/cm2		kg/cm2		kg/cm2		kg/cm2		kg/cm2		kg/cm2		kg/cm2
1.1	A105 A350-LF2	A216 WCB	32.0	23.0	79.5	58.5	156.5	116.5	208.0	153.0	236.0	172.5	392.0	288.5	652.5	478.5
1.3		A352-LCB	28.5	21.5	74.0	54.5	148.0	109.0	195.0	143.0	221.5	162.0	367.5	269.0	612.0	448.5
1.7	A185-F2	A217-WC4 A217-WC5	32.0	23.0	79.5	58.5	158.5	116.5	211.0	155.0	237.5	174.5	395.5	290.5	659.5	483.5
1.9	A182-F12 A182-F11	A217-WC6	32.0	23.0	79.5	58.5	158.5	116.5	211.0	155.0	237.5	174.5	395.5	290.5	659.5	483.5
1.1	A182-F22	A217-WC9	32.0	23.0	79.5	58.5	158.5	116.5	211.0	155.0	237.5	174.5	395.5	290.5	659.5	483.5
1.11	A182-F21		32.0	23.0	79.5	58.5	158.5	116.5	211.0	155.0	237.5	174.5	395.5	290.5	659.5	483.5
1.13	A182-F5E	A217-C5	32.0	23.0	79.5	58.5	158.5	116.5	211.0	155.0	237.5	174.5	395.5	290.5	659.5	483.5
2.1	A182-F304 A182-F304H	A351-CF3 A351-CF8	30.0	23.0	77.5	56.5	153.0	112.5	202.0	148.0	229.0	169.0	380.0	279.5	633.0	464.5
2.2	A182-F316 A182-F316H	A351-CF3A A351-CF8A A351-CF3M A351-CF8M	30.0	23.0	77.5	56.5	153.0	112.5	202.0	148.0	229.0	169.0	380.0	279.5	633.0	464.5
2.3	A182-F304L A182-F316L		25.0	19.5	63.5	49.5	127.0	93.5	169.5	124.0	190.0	141.0	316.5	232.5	527.5	387.0
2.4	A182-F321 A182-F321H		30.0	23.0	77.5	56.5	153.0	112.5	211.0	155.0	229.0	169.0	380.0	279.5	633.0	464.5
3.17		A351-CN7M	25.0	19.5	63.5	49.5	127.0	93.5	169.0	124.0	190.0	141.0	316.5	232.5	527.5	387.0

* S/B = Seat / Backseat

(a) High Pressure Hydro Seat test as per Table 01 for Gate, Globe, Check & Ball Valves

(b) Air Seat & Low Pressure Hydro Seat Test 4 to 7 bar for Gate, Check & Ball valves

Class 150		Valve Flanges
Size NPS(“)		1/2	3/4	1	1½	2	2½	3	4	6	8	10	12	14	16	18	20	24
Size DN(mm)		15	20	25	40	50	65	80	100	150	200	250	300	350	400	450	500	600
RFD	RAISED FACE DIA	35	43	51	73	92	105	127	157.5	216	270	324	381	413	470	533.5	584.5	692.5
B	BORE DIA	12.5	19	25.4	38	51	64	76	102	152	203	254	305	336	387	438	489	591
O	OUT SIDE DIA	89	98	108	127	152.5	178	191	229	279.5	343	406.5	482.5	533.5	597	635	698.5	813
C	THICKNESS	10	10.5	11.2	14.5	16	17.5	19	24	25.5	28.5	30.5	32	35	36.5	40	43	47.5
P	PCD	60.5	70	79.5	98.5	120.5	139.5	152.5	190.5	241.5	298.5	362	432	476.5	540	578	635	749.5
N	No. OF HOLES	4	4	4	4	4	4	4	8	8	8	12	12	12	16	16	20	20
D	DRILL DIA	16	16	16	16	19	19	19	19	22	22	25	25	28	28	32	32	35

Class 300		Valve Flanges
Size NPS(“)		1/2	3/4	1	1½	2	2½	3	4	6	8	10	12	14	16	18	20	24
RFD	RAISED FACE DIA	35	43	51	73	92	105	127	157.5	216	270	324	381	413	470	533.5	584.5	692.5
B	BORE DIA	12.5	19	25.4	38	51	64	76	102	152	203	254	305	336	387	432	483	584
O	OUT SIDE DIA	95.5	117.5	124	156	165	190.5	209.5	254	317.5	381	444.5	521	584	648	711	775	914.5
C	THICKNESS	14.5	16	17.5	20.5	22.5	25.5	28.5	32	36.5	41.5	47.5	51	54	57.5	60.5	63.5	70
P	PCD	67.5	82.5	89	114.5	127	149	168.5	200	270	330	387.5	451	514.5	571.5	628.5	686	813
N	No. OF HOLES	4	4	4	4	8	8	8	8	12	12	16	16	20	20	24	24	24
D	DRILL DIA	16	19	19	22	19	22	22	22	22	25	28	32	32	35	35	35	41

Class 600		Valve Flanges
Size NPS(“)		1/2	3/4	1	1½	2	2½	3	4	6	8	10	12	14	16	18	20	24
RFD	RAISED FACE DIA	35	43	51	73	92	105	127	157.5	216	270	324	381	413	470	533.5	584.5	692.5
B	BORE DIA	12.5	19	25.4	38	51	64	76	102	152	203	254	305	336	387	432	483	584
O	OUT SIDE DIA	95.5	117.5	124	156	165	190.5	209.5	273	355.5	419	508	559	603.5	686	743	813	940
C	THICKNESS	14.5	16	17.5	22.5	25.5	29	32	38	48	56	63.5	66.5	70	76	83	89	102
P	PCD	67	82.5	89	114.5	127	149	168.5	216	292	349.5	432	489	527	603.5	654	724	838
N	No. OF HOLES	4	4	4	4	8	8	8	8	12	12	16	20	20	20	20	24	24
D	DRILL DIA	16	19	19	22	19	22	22	25	28	32	35	35	38	41	45	45	51

Class 900		Valve Flanges
Size NPS(“)		1/2	3/4	1	1½	2	2½	3	4	6	8	10	12	14	16	18	20	24
RFD	RAISED FACE DIA	35	43	51	73	92	105	127	157.5	216	270	324	381	413	470	533.5	584.5	692.5
B	BORE DIA	12.5	17.5	22	35	48	57	73	98	146	191	238	283	311	356	400	445	534
O	OUT SIDE DIA	121	130	149.5	178	216	244.5	241.5	292	381	470	546	610	641.5	705	787.5	857	1041
C	THICKNESS	22.5	25.5	28.5	32	38	41	38	44.5	56	63.5	70	79	86	89	102	108	140
P	PCD	82.5	89	104	124	165	190.5	190.5	235	317.5	394	470	833.5	559	616	686	749	902
N	No. OF HOLES	4	4	4	4	8	8	8	8	12	12	16	20	20	20	20	20	20
D	DRILL DIA	22	22	25	28	25	28	25	32	32	38	38	38	41	45	50	54	67

Class 1500		Valve Flanges
Size NPS(“)		1/2	3/4	1	1½	2	2½	3	4	6	8	10	12	14	16	18	20	24
RFD	RAISED FACE DIA	35	43	51	73	92	105	127	157.5	216	270	324	381	413	470	533.5	584.5	692.5
B	BORE DIA	12.5	17.5	22	35	47.5	57	70	92	135.5	178	222	263.5	289	330	371.5	416	498.5
O	OUT SIDE DIA	121	130	149.5	178	216	244.5	267	311	394	483	584	673	749.5	826	914.5	984	1168
C	THICKNESS	22.5	25.5	28.5	32	38	41	48	54	83	92	108	124	133.5	146	162	178	203
P	PCD	82.5	89	102	124	165	190.5	203	241.5	317.5	394	483	571.5	635	705	775	832	991
N	No. OF HOLES	4	4	4	4	8	8	8	8	12	12	12	16	16	16	16	16	16
D	DRILL DIA	22	22	25	28	25	28	32	35	38	45	51	54	60	67	73	79	92

Corrosion may be caused by adverse exterior conditions in the Atmosphere, such as Salt Molecules present in the air, due to proximity of the Manufacturing plants close to the Sea Coast or due to emissions of Acids and other such corrosive substances into the Atmosphere by other Plants in adjoining locale. For instance, Aluminum Windows and Doors tends to oxidize if they are close to sea coast or used in Highly Corrosive Plant Areas. Corrosion in Values often results from Chemical Interaction between the Valve Body and the Agent through which it passes.

The following chart recommends the right body (Metal/Lining) Applications to handle Specific Chemicals. Other considerations to keep in mind while making selections of Valve Body include Temperature of the Media Flowing through Speed (Pressure) at which the-Media is flowing, whether the Media is Liquid or Slurry, Impurities present in the Media, and so on.

GM valves are available in a combination of exterior body, Inner Lining, Pressure Class Ratings, Filtering devices for both Liquid and Slurry Applications.

CORROSIVE	Cast Iron	Carbon Steel	Bronze	St.St.F 304	St.St.F 316	St.St. 12% Cr	Monet
Acetic Acid-Pure	C	C	C	B	A	A	A
Acetic Acid-10%	C	C	C	B	A	A	A
Acetic Acid-Anhydride	C	C	C	B	B	B	B
Alcohol Methyl 150°F	B	B	B	A	A	A	A
Alcohol Methyl (Methanol)	B	B	B	B	A	B	B
Ammonia-Conc.% Aq .Sol.	A	A	D	A	A	A	B
Ammonia Gas	A	A	D	A	A	A	B
Ammonium Chloride-Still	D	D	D	B	A	C	A
Ammonium Sulphate 1% & 5%-Agit. & Aer.	C	C	C	B	A	C	B
Ammonium-Saturated	C	C	C	C	A	C	B
AAmyl Acetate	C	C	B	B	B	C	B
Aniline	C	C	C	B	B	C	B
Arsenic Acid – 150°F	D	D	D	B	B	C	D
Asphalt	B	B	A	A	A	A	A
Barium Chloride-Sat.	C	C	B	A	A	C	B
Barium-Aqueous Sol.	C	C	C	B	A	C	B
Benzoic Acid	D	D	B	A	A	C	B
Benzol	B	B	A	A	A	A	A
Boric Acid	D	D	B	A	A	B	A
Butane Gas	B	B	A	B	B	B	B
Butyric Acid	D	D	C	A	A	A	B
Calcium Bisulphate	D	D	D	B	A	C	D
Calcium Carbonate	D	D	C	B	A	C	A
Calcium Chloride	C	C	B	C	B	C	A
Calcium Hydrochloride	D	D	D	C	C	D	D
Carbon Tetrachloride	B	B	B	A	A	A	B
Carbonic Acid	D	D	D	B	A	C	A
Chlorine-Dry Gas	B	B	C	B	B	B	B
Chlorine-Moist	D	D	D	D	D	D	C
Chromic Acid	C	C	D	B	A	C	B
Citric Acid-5%-Still	D	D	C	A	A	A	A
Citric Acid – Sat.	D	D	C	B	A	B	A
Copper Nitrate	D	D	D	A	A	A	C
Copper Sulphate	D	D	D	A	A	A	B
Creosote-crude	A	A	C	A	A	A	A
Dowtherms	B	B	A	A	A	A	A
Ethers	B	A	B	A	A	B	D
Ethyl Alcohol	B	B	B	A	A	B	B
Ethylene Glycol	A	A	A	A	A	A	A
Ferric Chloride	D	D	D	D	D	D	D
Ferric Sulphate	D	D	D	B	A	C	C
Ferrous Chloride	D	D	D	D	D	D	D
Ferrous Sulphate	D	D	B	B	B	B	B
Fluorine	D	D	D	D	D	D	D
Formaldehyde-cold	B	A	A	A	A	A	A
Formic Acid	D	D	B	C	A	C	B
Furfural	B	A	A	A	A	A	A
Gasoline Sour	B	B	C	A	A	B	B
Gasoline Refined	B	A	A	A	A	A	A
Gelatine	D	D	B	B	A	C	A
Glucose	B	B	A	A	B	B	A
Glue-Dry	B	A	A	A	A	A	A
Glycerine	B	B	B	A	A	A	A
Hydrochloric Acid (Muriatic)	D	D	D	D	D	D	C
Hydocyanic Acid	C	C	D	A	D	D	B
Hydrofluoric Acid	D	D	C	D	A	D	B
Hydrogen-Gas	B	B	B	A	A	A	A
Hydrogen Peroxide	C	C	D	A	A	B	D
Hydrogen Sulphide-Dry	B	B	D	A	A	B	C
Hydrogen Sulphide-Wet	C	C	D	A	A	B	D
Iodine-Dry-Wet	D	D	D	D	D	D	D
Kerosene	B	B	A	A	A	A	A
Laquer Solvents	B	B	B	A	A	B	B
Lactic Acid-1%	D	D	D	A	A	B	C
Lactic Acid-5%	D	D	D	A	A	B	C
Lactic Acid-5%-Boiling	D	D	D	A	B	D	D
Lactic Acid-10%-150°F	D	D	D	B	C	D	D
Lactic Acid-10%-70°F	D	D	D	B	C	D	D
Lime Sulphur	A	A	D	A	A	A	B
Linseed Oil	A	A	B	B	B	B	B
Lubricating Oil-Sour	C	C	D	A	A	B	C
Water(Fresh)	C	C	A	A	A	A	A
Water Distilled (Labor Grade)	D	D	C	A	A	D	C
Lubrication Oil-Refined	A	A	B	A	A	A	B
Magnesium Chloride	C	C	B	B	B	B	B
Magnesium Hydroxide	C	C	C	A	A	B	A
Magnesium Sulphate	C	B	B	B	B	C	B
Mercuric Chloride	D	D	D	D	C	D	C
Mercury	A	A	D	A	A	A	B
Methane Gas	B	B	A	B	B	B	B
Methylethylketone	A	A	A	A	A	A	A
Milk (Fresh or Sour)	D	D	B	A	A	B	A
Naphtha (Crude or Pure)	B	B	B	A	A	B	B
Natural Gas	B	B	B	A	A	A	A
Nickel Chloride	D	D	D	B	B	C	B
Nickel Sulphate	D	D	B	B	B	D	B
Nitric Acid-Crude	D	D	D	C	B	D	D
Nitric Acid-5%+50%	D	D	D	A	A	A	D
Nitric Acid- Conc. 70°F	D	D	D	A	A	A	D
Nitric Acid-Conc. Boiling	D	D	D	C	B	D	D
Nitric Acid-Fuming Conc. 110°F	D	D	D	A	A	B	D
Nitric Acid-Fuming Conc. Boiling	D	D	D	D	D	D	D
Nitrobenzene	B	B	D	B	A	B	B
Oils-Miner. & Vegetable	B	B	B	A	A	B	B
Oxalic Acid-10% – 70oF	D	D	B	D	C	D	D
Oxalic Acid – 10% – Boiling	D	D	B	D	C	D	D
Oxygen	B	B	A	A	A	A	A
Petroleum Oils – Crude	B	B	C	A	A	A	A
Phosphoric Acid – Crude	C	C	D	D	D	D	D
Phosphoric Acid – 5% & Boiling	D	D	D	A	A	B	C
Phosphoric Acid – 10% Still	D	D	D	B	A	C	C
Phosphoric Acid – 10% Agitated	D	D	D	C	D	D	D
Phosphoric Acid – 10% Aer.-Boil	D	D	D	D	A	D	D
Picric Acid	C	C	D	A	A	C	C
Potassium Chloride	B	B	B	C	C	B	B
Potassium Cyanide	B	B	D	A	A	B	B
Potassium Hydroxide – 5% Still	A	A	D	A	A	A	A
Potassium Hydroxide – 50% Boil	B	A	D	A	A	A	A
Potassium Nitrate	B	B	B	A	A	A	B
Propane Gas	B	B	A	A	A	A	A
Sea Water	D	D	B	B	A	D	A
Soap Solution	B	A	A	A	A	A	A
Sodium Bicarbonate	C	C	B	A	A	A	B
Sodium Bicarbonate-5+50%	B	B	B	A	A	A	B
Sodium Chloride	C	C	B	B	A	C	A
Sodium Cyanide	B	B	D	B	B	A	B
Sodium Hydroxide	B	C	B	B	A	C	A
Sodium Hypochlorite	D	D	D	C	B	D	C
Sodium Nitrate	B	B	B	B	A	B	B
Sodium Phosphate (di-Basic)	C	C	C	B	B	C	B
Sodium Phosphate (tri-Basic)	B	B	D	B	B	C	B
Sodium Sulphate	B	B	B	B	A	B	A
Sodium Sulphide	B	B	D	B	A	B	A
Steam	A	A	C	A	A	A	A
Stearic Acid – Conc.	C	C	C	A	A	C	B
Sulphur – 500°F – Molten	C	C	D	A	A	B	B
Sulphur Dioxide	B	B	B	A	A	B	A
Sulphuric Acid -< 10%	D	D	C	C	B	D	A
Sulphuric Acid -50% + 70°F	B	B	A	A	A	B	A
Sulphuric Acid -50% Boil	D	D	D	D	D	D	C
Sulphuric Acid-Conc. 70°F	B	B	A	A	A	B	A
Sulphuric Acid-300°F	D	D	C	D	D	D	C
Sulphuric Acid – Fuming	D	D	C	C	B	D	C
Sulphuric Acid – Sat.	D	D	C	C	B	D	C
Sulphuric Acid – Spray	D	D	D	C	C	D	D
Tannic Acid – 10%	C	C	B	A	A	C	B
Tannic Acid – 10% – Boil	D	D	C	C	C	D	C
Tar	A	A	A	A	A	A	A
Tartaric Acid – 70°F	D	D	B	A	A	C	A
Tartaric Acid – 150°F	D	D	B	B	A	B	B
Trichloroethylene	C	C	B	B	B	C	A
Turpentine	B	B	B	A	A	B	A
Tomato Juice	C	C	C	A	A	B	A
Vinegar	D	D	B	A	A	A	A
Zinc Chloride	C	D	D	D	D	C	B
Zinc Sulphate	D	D	B	B	B	C	B

Note : A – Good Resistance; B – Satisfactory; C – Poor; D – Not Recommended;

U.S. MESH	INCHES	MICRONS	MILLIMETERS
3	0.265	6730	6.73
4	0.187	4760	4.76
5	0.157	4000	4
6	0.132	3360	3.36
7	0.111	2830	2.83
8	0.0937	2380	2.38
10	0.0787	2000	2
12	0.0661	1680	1.68
14	0.0555	1410	1.41
16	0.0469	1190	1.19
18	0.0394	1000	1
20	0.0331	841	0.841
25	0.028	707	0.707
30	0.0232	595	0.595
35	0.0197	500	0.5
40	0.0165	400	0.4
45	0.0138	354	0.354
50	0.0117	297	0.297
60	0.0098	250	0.25
70	0.0083	210	0.21
80	0.007	177	0.177
100	0.0059	149	0.149
120	0.0049	125	0.125
140	0.0041	105	0.105
170	0.0035	88	0.088
200	0.0029	74	0.074
230	0.0024	63	0.063
270	0.0021	53	0.053
325	0.0017	44	0.044
400	0.0015	37	0.037

For Flame arrestors & breather valve selection – IEC/NEC reference

Propane / hydrocarbon family (IEC 60079-11 | ATEX / IECEx)

NEC equivalent: Group D

The most common gas group in oil & gas, petrochemical and storage applications. Gases have wide flame quenching diameters and relatively low propagation velocities.

MESG

0.45 – 0.9 mm

MIC Ration

0.80

Typical LFL

1.7 – 5%

Typical UFL

8 – 15%

TYPICAL GASES

Propane · Butane · Methane (pipeline) · Acetone · Ammonia · Toluene · Xylene · Diesel vapour · Naphtha

INDUSTRY APPLICATIONS

Petroleum storage tanks · LPG installations · Petrochemical vessels · Fuel oil day tanks · Pharmaceutical solvent tanks

SELECTION RECOMMENDATIONS

FLAME ARRESTOR

Standard deflagration flame arrestors (in-line or end-of-line) per EN 12874 / ISO 16852. Crimped-ribbon or parallel-plate element, 316 SS housing. Atmospheric or low-pressure service.

BREATHER VALVE

Spring-loaded pallet breather valves (pressure / vacuum relief). API 2000 / EN ISO 28300 rated. Aluminium or SS body. Standard pressure setting 35 mbar / -3.5 mbar typical for fixed-roof tanks.

Ethylene / Town Gas family (IEC 60079-11 | ATEX / IECEx)

NEC equivalent: Group C

Gases with narrower quenching gaps and faster flame propagation than Group IIA. Require a higher-specification arrestor with tighter element geometry. Common in chemical and polymer plants.

MESG

0.28 – 0.45 mm

MIC Ration

0.45 – 0.80

Typical LFL

2.7 – 3.1%

Typical UFL

28 – 36%

TYPICAL GASES

Ethylene · Ethylene oxide · Town gas / coal gas · Cyclopropane · Butadiene · Diethyl ether

INDUSTRY APPLICATIONS

Ethylene crackers · Polymer production · Town gas distribution · Refrigeration (ethylene) · Chemical reactors

SELECTION RECOMMENDATIONS

FLAME ARRESTOR

Reinforced deflagration or detonation-rated flame arrestors. Tighter crimp elements; EN 12874 Group IIB certification mandatory. Consider detonation arrestors where piping > 3 m from source.

BREATHER VALVE

IIB-rated breather valves with stainless internals. Flame cell inserts with tighter gap geometry. Pressure/vacuum pallets with Hastelloy or Monel seats for corrosive service.

Hydrogen / Acetylene family (IEC 60079-11 | ATEX / IECEx)

NEC equivalent: Groups A & B

Highest ignition sensitivity class. Very narrow MESG, very low MIC ratio. Flames propagate rapidly and can transition from deflagration to detonation (DDT) with minimal run-up distance. Requires the most stringent

MESG

<0.28 mm

MIC Ration

<0.45

Typical LFL

4% (H₂)

Typical UFL

75% (H₂)

TYPICAL GASES

Hydrogen (H₂) · Acetylene (C₂H₂) · Carbon disulphide (CS₂) · Water gas · Hydrogen sulphide (at high %)

INDUSTRY APPLICATIONS

Hydrogen generation/storage · Electrolysers · Fuel cell systems · Acetylene plants · Chemical synthesis · Battery rooms (H₂ off-gas)

SELECTION RECOMMENDATIONS

FLAME ARRESTOR

Mining-grade certified flame arrestors.
Equipment must carry Group I (mining) certification — Group IIA certification alone is NOT sufficient for underground use even though MESG values overlap.

BREATHER VALVE

Specialist underground-rated pressure relief.
Mining-certified body required. Surface-type breather valves are not applicable to underground firedamp service.

Firedamp / Underground Mining (IEC 60079-11 | ATEX / IECEx)

NEC equivalent: —

A separate classification for methane encountered in underground mines (colliery methane / firedamp). Equipment certified to Group I is specifically designed and tested for the underground coal mining environment.

MESG

>0.9 mm

MIC Ration

>0.80

Typical LFL

Typical UFL

>0.9 mm

TYPICAL GASES

Methane (firedamp / CH₄) — underground mine atmosphere only.

INDUSTRY APPLICATIONS

Underground coal mines · Tunnelling operations · Colliery ventilation · Methane drainage systems

SELECTION RECOMMENDATIONS

FLAME ARRESTOR

Mining-grade certified flame arrestors.
Equipment must carry Group I (mining) certification — Group IIA certification alone is NOT sufficient for underground use even though MESG values overlap.

BREATHER VALVE

Specialist underground-rated pressure relief.
Mining-certified body required. Surface-type breather valves are not applicable to underground firedamp service.

MESG = Maximum Experimental Safe Gap · MIC = Minimum Igniting Current ratio · FA = Flame Arrestor · BV = Breather Valve

Standards: IEC 60079-11, EN 12874, ISO 16852, API 2000 (breather valves), ATEX Directive 2014/34/EU

IEC group	NEC equiv.	MESG (mm)	MIC ratio	Typical gases	FA type
Group I	—	> 0.9	> 0.8	Firedamp (CH₄, mining)	Mining-rated detonation arrestor
Group IIA	D	0.9 - 0.45	> 0.8	Propane, Methane, Butane, Acetone, Ammonia, Toluene	Standard deflagration arrestor · Spring-loaded BV
Group IIB	C	0.45 - 0.28	0.45 - 0.80	Ethylene, Ethylene oxide, Town gas, Cyclopropane	Reinforced deflagration or detonation arrestor
Group IIC	A & B	< 0.28	< 0.45	Hydrogen (H₂), Acetylene (C₂H₂), Carbon disulphide	IIC-rated detonation arrestor · High- spec BV with N₂ purge

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