How do I access the W-9 Form?

You can access the current W9 forms for either Praxair Distribution Inc. or Linde Gases US by clicking the appropriate button below. Praxair Distribution Inc. W-9 Form Linde Gases US W-9 Form

What are the Physical Properties of Gases?

Density, Boiling Point, Critical Pressure, Critical Temperature, Mole Weight, Specific Volume and Specific Gravity of Gases

Name	Gas Density (NTP) lb/ft³	Gas Density (NTP) kg/m³	Boiling Point ^°F	Boiling Point ^°C	Critical Pressure psia	Critical Pressure bar	Critical Temperature ^°F	Critical Temperature ^°C	Mole Weight	Specific Volume ft³/lb	Specific Volume m³/kg	Specific Gravity (air=1)
Acetylene	0.0733 a	1.17 a	-119.2	-84	897.8	63.1	95.36	35.2	26.04	14.43	0.901	0.908
Air	0.0807 a	1.29 a	-317.8	-194.4	547.4	38.5	-221.08	-140.6	28.85	13.3	0.83	1
Ammonia	0.045	0.72	-28.1	-33.4	1636.1	115	270.32	132.4	17.03	22.6	1.411	0.597
Argon	0.1034	1.66	-302.6	-189.4	705.4	49.6	-188.32	-122.4	39.95	9.67	0.604	1.378
Arsine	0.2	3.2	-80.5	-62.5	957	67.3	211.82	99.9	77.95	5	0.312	2.69
Boron Trichloride	0.303	4.85	54.3	12.4	561.4	39.5	353.84	178.8	117.17	3.3	0.206	4.03
Boron Trifluoride	0.1777	2.85	-147.6	-99.8	723	50.8	10.04	-12.2	67.81	5.6	0.35	2.387
Butadiene, 1, 3-	0.1516 a	2.43 a	24.1	-4.4	627.5	44.1	305.6	152	54.09	6.9	0.431	1.878
Butane, 3-	0.1588	2.54	31.1	-0.5	550.7	38.7	305.6	152	58.12	6.4	0.4	2.11
Butene, 1-	0.1477 b	2.37 b	20.7	-6.3	583.4	41	295.52	146.4	56.12	6.7	0.418	1.997
Carbon Dioxide	0.1140 a	1.83 a	-109.1	-78.4	1070.6	75.3	87.8	31	44.01	8.76	0.5471	1.522
Carbon Monoxide	0.0781 a	1.25 a	-312.7	-191.5	507.4	35.7	-220.36	-140.2	28.01	13.8	0.862	0.967
Chlorine	0.1859	2.98	-29.3	-34.1	1118.4	78.6	291.2	144	70.91	5.4	0.337	2.49
Deuterium	0.0112	0.18	-417.1	-249.5	239.2	16.8	-390.82	-234.9	4.03	95.9	5.987	0.1497
Dichlorosilane	0.2601	4.17	46.8	8.2	678.2	47.7	348.8	176	101.01	3.83	0.239	3.52
Disilane	0.179	2.87	6.3	-14.3	747.2	52.5	303.53	150.85	62.22	6.21	0.388	2.38
Ethane	0.0775 b	1.24 b	-127.5	-88.6	712.8	50.1	90.32	32.4	30.07	12.8	0.799	1.048
Ethylene	0.0787 a	1.26 a	-154.7	-103.7	742.1	52.2	49.82	9.9	28.05	13.8	0.862	0.975
Halocarbon 14	0.228	3.65	-198.3	-127.9	542.4	38.1	-49.9	-45.5	88	4.39	0.274	3.038
Halocarbon 22	0.2335	3.74	-41	-41	721.9	50.8	204.8	96	86.47	4.4	0.275	3.11
Halocarbon 23	0.182	2.92	-115.6	-82	697	49	78.26	25.7	70.01	5.5	0.343	2.2636
Halocarbon 116	0.3608	5.78	-108.8	-78.2	432	30.4	67.5	24.3	138.01	2.8	0.175	4.773
Halocarbon 134A	0.4683 b	7.50 b	-15.7	-26.5	589.6	41.5	213.98	101.1	102.03	2.14	0.134	-
Halocarbon 218	0.5	8.01	-34.1	-36.7	388.7	27.3	161.42	71.9	188.02	2.02	0.126	6.69
Halocarbon C₃18	0.55	8.82	21.56	-5.8	403.3	27.8	238.6	114.8	200.03	1.85	0.12	7.33
Helium	0.0103	0.16	-452.1	-268.9	33.2	2.3	-450.4	-268	4	96.6	6.031	0.138
Hexane, -n	0.2228	3.569	155.66	68.7	430.6	29.7	453.6	234.2	86.18	4.996	0.31	0.66
Hydrogen	0.005	0.08	-423	-252.8	188.1	13.2	-399.82	-239.9	2.02	191.7	11.968	0.0696
Hydrogen Bromide	0.208	3.33	-88.1	-66.7	1234.5	86.8	193.64	89.8	80.92	4.8	0.3	2.77
Hydrogen Chloride	0.0943	1.51	-121	85	1197.7	82.5	124.5	51.4	36.46	10.6	0.66	1.27
Hydrogen Sulfide	0.089	1.43	-76.5	-60.3	1306.5	91.9	212.72	100.4	34.08	11.23	0.701	1.189
Isobutane	0.1553	2.49	10.9	-11.7	529.1	37.2	275	135	58.13	6.5	0.406	2.064
Isobutylene	0.1440 b	2.31 b	19.6	-6.9	580.2	40.8	292.46	144.7	56.12	6.7	0.418	1.947
Krypton	0.217	3.48	-244.1	-153.4	796.5	56	-82.84	-63.8	83.8	4.61	0.288	2.899
Methane	0.0448 a	0.72 a	-258.7	-161.5	673.1	47.3	-115.78	-82.1	16.04	23.7	1.48	0.555
Methyl Chloride	0.1319 b	2.11 b	-11.6	-24.2	2438.1	171.4	289.58	143.1	50.49	7.6	0.474	1.784
Neon	0.052	0.83	-411	-246.1	394.7	27.8	-379.66	-228.7	20.18	19.21	1.199	0.696
Nitric Oxide	0.0767 b	1.23 b	-241.2	-151.8	949.4	66.7	-135.22	-92.9	30.01	13	0.812	1.036
Nitrogen	0.0725	1.16	-320.4	-195.8	492.2	34.6	-237.82	-149.9	28.01	13.8	0.862	0.967
Nitrogen Dioxide	0.2119	3.39	70.2	21.2	1469.6	103.3	316.76	158.2	46.01	4.7	0.293	2.62
Nitrogen Trifluoride	0.186	2.98	-200.2	-129	657.2	46.2	-38.74	-39.3	71	5.4	0.337	2.46
Nitrous Oxide	0.115	1.84	-127.3	-88.5	1052.2	74	97.52	36.4	44.01	8.7	0.543	1.53
Oxygen	0.0828	1.33	-297.4	-183	731.4	51.4	-181.48	-118.6	32	12.1	0.755	1.105
Pentane	0.1866	2.988	96.93	36.07	488.63	33.69	385.7	196.5	72.15	5.4	0.337	2.491
Phosphine	0.0875	1.4	-125.9	-87.7	947.9	66.6	124.88	51.6	34	11.4	0.712	1.184
Propane	0.1166	1.87	-43.8	-42.1	618.7	43.5	206.24	96.8	44.11	8.5	0.531	1.55
Propylene	0.1114	1.79	-53.9	-47.7	667.1	46.9	197.24	91.8	42.08	9.06	0.566	1.48
Silane	0.0837	1.34	-168.7	-111.5	702.5	49.4	25.88	-3.4	32.12	12.04	0.752	1.114
Silicon Tetrachloride	0.442	7.08	135.7	57.6	573.3	40.3	454.82	234.9	169.9	2.28	0.142	5.8
Sulfur Dioxide	0.1666	2.67	14	-10	1143.5	80.4	315.68	157.6	64.06	5.9	0.368	2.263
Sulfur Hexafluoride	0.3845	6.16	-82.8	-63.8	545.2	38.3	113.9	45.5	146.05	2.5	0.156	5.11
Trichlorosilane	0.3500 b	5.61 b	89.6	32	597.3	42	402.08	205.6	135.45	2.85	0.178	4.7
Tungsten Hexafluoride	0.793	12.7	67.1	19.5	629.5	44.3	339.44	170.8	297.84	1.24	0.077	10.8
Xenon	0.342	5.48	-162.6	-108.1	846.7	59.5	61.88	16.6	131.3	2.9	0.181	4.56

Chemical Formula, 2008 TLV, Flammable Range, Odor and IDLH of Gases

Name	Chemical Formula	2008 TLV ppm	2008 TLV mg/m³	Flammable Range LEL air	Flammable Range UEL air	Odor	IDLH ppm
Acetylene	C₂H₂	Simple Asphyxiant	Simple Asphyxiant	2.5	100	Ethereal
Air	N/A	N/A	N/A	N/A	N/A	None
Ammonia	NH₃	25	17	16	25	Pungent, Irritating	300
Argon	Ar	Simple Asphyxiant	Simple Asphyxiant	Nonflammable	Nonflammable	None
Arsine	AsH₃	0.005	0.016	5.1	78	Garlic-like	3
Boron Trichloride	BCl₃	None Established	None Established	Nonflammable	Nonflammable	Pungent, Irritating	100
Boron Trifluoride	BF₃	C 1.0	C 3.0	Nonflammable	Nonflammable	Pungent, Suffocating	25
Butadiene, 1,3-	CH₂:CHCH:CH₂	2	4	2	11.5	Mildly Aromatic	2000
Butane, n-	C₄H₁₀	1000	2377	1.9	8.5	Natural Gas-like
Butene, 1-	CH₃CH₂CH:CH₂	250	574	1.6	10	Natural Gas-like
Carbon Dioxide	CO₂	5000	9000	Nonflammable	Nonflammable	None	40000
Carbon Monoxide	CO	25	29	12	75	None	1200
Chlorine	Cl₂	0.5	1	Nonflammable	Nonflammable	Pungent, Irritating	10
Deuterium	D₂	Simple Asphyxiant	Simple Asphyxiant	5	75	None
Dichlorosilane	SiH₂Cl₂	None Established	None Established	4.7	99	Pungent, Suffocating	100
Disilane	(SiH₃)2	5	13	Unknown, Pyrophoric	Unknown, Pyrophoric	Repulsive, Choking
Ethane	C₂H₆	1000	1230	1000	1230	None
Ethylene	CH₂:CH₂	200	229	2.7	36	Sweet
Halocarbon-14	CF₄	None Established	None Established	Nonflammable	Nonflammable	None
Halocarbon-22	CHClF₂	1000	3537	Nonflammable	Nonflammable	Nearly Odorless
Halocarbon-23	CHF₃	None Established	None Established	Nonflammable	Nonflammable	None
Halocarbon-116	C₂F₆	None Established	None Established	Nonflammable	Nonflammable	None
Halocarbon-134A	CF₃CH₂F	None Established	None Established	Nonflammable	Nonflammable	Slightly Ethereal
Halocarbon-218	C₃F₈	None Established	None Established	Nonflammable	Nonflammable	Slightly Sweet
Halocarbon-C318	C₄F₈	None Established	None Established	Nonflammable	Nonflammable	None
Helium	He	Simple Asphyxiant	Simple Asphyxiant	Nonflammable	Nonflammable	None
Hexane, n-	C₆H₁₄	50	180	1.1	7.5	Mild
Hydrogen	H₂	Simple Asphyxiant	Simple Asphyxiant	4	75	None
Hydrogen Bromide	HBr	C 2.0	C 7	Nonflammable	Nonflammable	Irritating	30
Hydrogen Chloride	HCl	C 2.0	C 3	Nonflammable	Nonflammable	Pungent, Suffocating	50
Hydrogen Sulfide	H₂S	10	14	4.3	46	Rotten Eggs	100
Isobutane	CH(CH₃)3	1000	2378	1.8	8.4	Slight
Isobutylene	(CH₃)2C:CH₂	250	574	1.8	9.6	Coal Gas
Krypton	Kr	Simple Asphyxiant	Simple Asphyxiant	Nonflammable	Nonflammable	None
Methane	CH₄	1000	656	5	15	None
Methyl Chloride	CH₃Cl	50	103	8.1	17.4	Faintly, Sweet Ethereal	2000
Neon	Ne	Simple Asphyxiant	Simple Asphyxiant	Nonflammable	Nonflammable	None
Nitric Oxide	NO	25	31	Nonflammable	Nonflammable	Slightly Irritating	100
Nitrogen	N₂	Simple Asphyxiant	Simple Asphyxiant	Nonflammable	Nonflammable	None
Nitrogen Dioxide	NO₂	3	5.6	Nonflammable	Nonflammable	Irritating	20
Nitrogen Trifluoride	NF₃	10	29	Nonflammable	Nonflammable	Mold-like	1000
Nitrous Oxide	N₂O	50	90	Nonflammable	Nonflammable	Slightly Sweet
Oxygen	O₂	N/A	N/A	Nonflammable	Nonflammable	None
Pentane, n-	C₅H₁₂	600	1770	1.5	7.8	Parrafinic	1500
Phosphine	PH₃	0.3	0.42	1.6	98	Garlic-Like	50
Propane	C₃H8	1000	1804	2.1	9.5	Natural Gas-like	2100
Propylene	CH₂:CHCH₃	500	861	2	11.1	Slightly Sweet
Silane	SiH₄	5	6.6	1.4	96	Choking
Silicon Tetrachloride	SiCl₁₄	None Established	None Established	Nonflammable	Nonflammable	Pungent, Suffocating	100
Sulfur Dioxide	SO₂	2	5.2	Nonflammable	Sharp,	Pungent	100
Sulfur Hexafluoride	SF₆	1000	5973	Nonflammable	Nonflammable	None
Trichlorosilane	SiHCl₃	None Established	None Established	7	83	Pungent, suffocating	100
Tungsten Hexafluoride	WF₆	None Established	None Established	Nonflammable	Nonflammable	None	30
Xenon	Xe	Simple Asphyxiant	Simple Asphyxiant	Nonflammable	Nonflammable	None