Thermal Mass Flow Meter Model Selection Guideline

The flow range applies to Silver Automation Instruments SRK-100 series thermal mass flow meters.

1. Thermal massFlow range and Flow meter size selection

1. Flow range Table Reference

Table 1: Air mass flow meter flow range selection table

Table 2:Air, N2 (nitrogen) ,O2 (oxygen gas),H2 (hydrogen) Flow Meter Flow range table

Table 3: Argon (Ar)gas, Helium(He)gas, Natural Gas Methane ,LPG, City Gas, Chlorine Gas flow measurement flow range table

All thermal dispersion mass flow meters are calibrated before leaving factory, the upper limit of flow range will be indicated on the name plate of flow meter.

2. Lower and upper limit of the flow range

1) Lower limit: the thermal mass flow meter is sensitive to low flow, it can detect 0.05 m/s flow rate, so in normal condition, lower limit can be ignored.

2) Upper limit: It is normally decided by process design; the flow meter upper limit is more than 20% of design limit.

3) Mixed gas measurement: For mixed gas, the ender user should provide standard density and mole ratio (different gas percentage of the mix gas). The measuring range is decided by our factory. It is normally calibrated by air or nitrogen flow, and then corrected by meter conversion coefficient.

3. Statement

The flow range is limited by equipment; please get confirmation from factory before purchasing.

Air mass flow rangeselection table

DN (mm)	Min (kg/h)	Normal(kg/h)	Max(kg/h)
25	0-1.14	0-78	0-204
40	0-2.92	0-194	0-525
50	0-4.57	0-310	0-822
80	0-11.7	0-775	0-2106
100	0-18.3	0-1292	0-3291
150	0-41.1	0-2584	0-7404
200	0-73.1	0-5168	0-13613
250	0-114	0-7752	0-20564
300	0-165	0-11162	0-29613
400	0-292	0-19845	0-52645
500	0-457	0-31008	0-82257
600	0-658	0-44652	0-118450
700	0-896	0-60775	0-161224
800	0-1170	0-79380	0-210578
900	0-1481	0-100465	0-266513
1000	0-1828	0-124032	0-329028
1200	0-2632	0-178606	0-473801
1500	0-4113	0-279072	0-740314
2000	0-7312	0-496128	0-1316113

Four kinds common gas calibrated range selection table

DN(mm)	Air	(N2)	(O2)	(H2)
25	60	60	60	28
40	150	150	150	70
50	240	240	240	112
80	600	600	600	282
100	1000	1000	1000	470
150	2000	2000	2000	940
200	4000	4000	4000	1880
250	6000	6000	6000	2820
300	8640	8640	8640	4060
400	15360	15360	15360	7219
500	24000	24000	24000	11280
600	34560	34560	34560	16243
700	47040	47040	47040	22108
800	61440	61440	61440	28876
900	77760	77760	77760	77807
1000	96000	96000	96000	45120
1200	138240	138240	138240	64972
1500	216000	216000	216000	101520
2000	384000	384000	384000	180480

Note: The flow unit in above table is Nm3/h, corresponding flow rate is 34m/s,when in application, it can expand to 50m/s

Common gas upperlimit (Nm3/h)

DN (mm)	Argon (Ar)	Helium (He)	Natural Gas	Methane Gas	LPG	City Gas	Chlorine Gas
25	82	37	58	51	84	44	109
40	207	94	147	129	211	111	273
50	331	151	235	206	339	177	436
80	828	378	588	516	847	444	1092
100	1380	630	980	860	1143	740	1820
150	2760	1260	1960	1720	2826	1480	3640
200	5520	2520	3920	3440	5652	2960	7280
250	8280	3780	5880	5160	8478	4440	10920
300	11923	5443	8467	7430	12208	6393	15724
400	21196	9676	15052	13209	21703	11366	27955
500	33120	15120	23520	20640	33912	17760	43680
600	47692	21772	33868	29721	48833	25574	62899
700	64915	29635	46099	40454	66467	34809	85612
800	84787	38707	60211	52838	86814	45465	111820
900	107308	48988	76204	66873	109874	57542	141523
1000	132480	60480	94080	82560	135648	71040	174720
1200	190771	87091	135475	118886	195333	102297	251596
1500	298080	136080	211680	185760	305208	159840	393120
2000	529920	241920	376320	330240	542592	284160	698880

Standard state: temperature 0 ℃, Pressure 1.01325×105Pa (absolute pressure)

Flow unit option: kg/h,t/h,Nm3/h,Nkm3/h.

2. Installation types

1. Recommendation:

When the pipeline≤Ø100, Flange thermal mass flow meter is recommended.

When the pipeline ＞Ø100,Insertion thermal mass flow meter is recommended.

2. If the field pipes have been installed, no installation flanges available, Insertion type can be selected. Please specify when ordering.