Conversion of valve nominal diameter and inch | comparison table

Valve nominal diameter|valve nominal diameter
Definition of valve nominal diameter:

Nominal diameter (or nominal diameter), also known as average outer diameter, refers to the size of all piping accessories in the piping system. The nominal diameter is a convenient round integer for reference. The nominal diameter of the valve is marked with a number followed by the letter DN. DN represents the internal diameter of the pipe in millimeters. For example, DN50 is 50 millimeters. The American standard valve is usually expressed in inches (“), and the fractional valve is to express the internal diameter of the pipe in inches. The conversion formula is 1”=25.4mm, such as 8” is equivalent to the domestic DN200mm.

Valve nominal diameter comparison table:
The nominal diameter of the valve (NPS-NOMINAL PIPE SIZE) is not necessarily the same as the diameter of the flow channel. For the selection of its size, the required Cv value is calculated from the conditions of the conveying fluid, and then the Cv value (refer to the manufacturer’s catalog) is used to select a suitable valve The nominal diameter (NPS) is the nominal inner diameter that characterizes the valve diameter. The national standard is expressed by DN and the unit is mm. The American standard is expressed in inches. The conversion relationship between inch NPS and metric DN is as follows:

No.	inch	DN/mm	No.	inch	DN/mm	No.	inch	DN/mm
1	1/8	4	17	10	250	33	42	1050
2	1/4	8	18	12	300	34	48	1200
3	3/8	10	19	14	350	35	54	1350
4	1/2	15	20	16	400	36	60	1500
5	3/4	20	21	18	450	37	64	1600
6	1	25	22	20	500	38	72	1800
7	11/4	32	23	22	550	39	80	2000
8	11/2	40	24	24	600	40	84	2100
9	2	50	25	26	650	41	88	2200
10	21/2	65	26	28	700	42	96	2400
11	3	80	27	30	750
12	31/2	90	28	32	800
13	4	100	29	34	850
14	5	125	30	36	900
15	6	150	31	38	950
16	8	200	32	40	1000

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

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