Solenoid Valve Threads Flanges

Solenoid Valves in fact just about any valve type be it Manual, air or motor actuated butterfly, gate, ball, Knife, globle or piston valve it will need to be connected to existing pipe work by means of a thread or flange connection.

Threads are given by size and type, Flanges are given by size, type and pressure rating and there are many variations for each which can lead to some confusion.

Technical information and dimensions for some of the more common BSP, BSPT, NPT threads and PN and ANSI flange types.

  • NPT - American Standard Pipe Taper Thread (National Pipe Thread).
  • FPT - American Standard Female Pipe Taper Thread.
  • NPSC - American Standard Straight Coupling Thread.
  • BSP - British Standard Pipe (Can mean either BSPP Parallel or BSPT Tapered).
  • BSPP - British Standard Pipe Parallel, also denoted as G.
  • BSPT - British Standard Pipe Tapered.
  • GHT - Garden Hose Thread
  • G Thread - British Gas Thread Parallel (same as BSPP thread).
  • R Thread - British Tapered Thread (same as BSPT thread).

Threads

Parallel Internal and External Threads.

Parallel threads are fastening threads and require the use of a seal such as an O ring or dowty bonded seal / washer to seal against valve body by the port and the pipe fitting hexagon being screwed into the valve.

Parallel threads

Tapered Internal and External Threads.

Tapered threads are fastening and sealing joining threads that create a pressure seal between the fitting thread and valve body thread, typically in conjunction with a sealing compound such as PTFE or liquid thread sealant.

Tapered thread

NPT - National Pipe Thread Sizes (US Standard) and identification.

Nominal Pipe Size (Inches)Threads per Inch (TPI)Outside Diameter (Inches)Outside Diameter (mm)
1/8" 27 0.405 10.3
1/4" 18" 0.54 13.7
3/8" 18 0.675 17.15
1/2" 14 0.84 17.9
3/4" 14 1.05 26.67
1" 11.5 1.315 33.4
11/4" 11.5 1.66 42.16
11/2" 11.5 1.9 48.26
2" 11.5 2.375 60.33
21/2" 8 2.875 73.03
3" 8 3.5 88.9
31/2 8 4.0 101.6
41/2 8 5.0 127.0
5 8 5.563 141.3
6 8 6.625 168.275
8 8 8.625 219.075
10 8 10.75 273.05
12 8 12.75 323.85
14 8 14.0 355.6
16 8 16.0 406.4

BSP - British Straight Thread and British Tapered Thread Sizes and identification.

Nominal Pipe Size (Inches)Threads per Inch (TPI)Major Diameter (Inches)Outside Diameter (mm)
1/8" 28 0.383 9.7282
1/4" 19 0.518 13.1572
3/8" 19 0.656 16.6624
1/2" 14 0.825 20.955
5/8 14 0.902 22.9108
3/4" 14 1.041 26.4414
1" 11 1.309 33.2486
11/4" 11 1.65 41.91
11/2" 11 1.882 47.8028
13/4" 11 2.116 53.7464
2" 11 2.347 59.6138
21/4" 11 2.587 65.7098
21/2" 11 2.96 75.184
3" 11 3.46 87.884
31/2" 11 3.95 100.33
4" 11 4.45 113.03
41/2" 11 4.95 125.73
5" 11 5.45 138.43
51/2" 11 5.95 151.13
6" 11 6.45 163.83

How to measure Internal and External Threads

How to measure threads : Measure the thread diameter, for male threads this is the OutSide Major Diameter (OD), for female threads it is the Internal Minor Diameter (ID). Then measure the thread pitch, or number of threads over a measured inch. Use a ruler and count how many threads there are in an inch.

Solenoid valve thread

Thread Identification

This is a basic guide for thread identification, there are many thread varients for thread angle, helix angle, lead angle and pitch, with either rounded, flat or sharp cutting thread specifications. Then measure the thread pitch, or number of threads over a measured inch. Use a ruler and count how many threads there are in an inch.

For example you have a brass solenoid valve, you measure the external thread of the fitting going into the valve port and it is 0.825 inches or about 21mm, you count the threads for a measured inch being 14. Looking at the chart on the left you can see this equates to 1/2" BSP Thread.

To be safe for commercial and high pressure applications you can use a thread gauge to check the thread which will ensure you have the correct thread.

solenoid valve thread type

Thread Standards : Relevant to Solenoid Valves

Most threads conform to industrial or National standards that provide uniform conformity on thread angle, thread pitch and thread diameter.

Common Threads

  • ANSI/ASME B1.1-1999 Unified Inch Screw Threads (Un & UNR Thread Types).
  • ANSI/ASME B1.20.1-1983 (R1992) Pipe thread general purpose (imperial).
  • DIN 2999, Pipe threads for tubes and fittings including parallel internal threads and taper external thread.
  • ISO261, ISO general purpose metric screw threads.

Thread Pitch

  • Imperial: Thread pitch is the number of threads per inch.
  • Metric: Thread is given as distance between the threads and diameter.

Common Piping Threads

  • NPT - American standard pipe taper (referred to as ANSI/ASME B1.20.1)
  • NPSC - American standard straight coupling pipe thread.
  • NPTR - American standard taper raining pipe thread.
  • NPSM - American standard straight mechanical pipe thread.
  • NPSL - American standard straight locknut pipe thread.
  • SO 7/1 American standard pipe taper thread referred to as DIN2999, BSP21, JISB0203
  • ISO228/1 Parallel pipe threads - equivalent to DIN ISO228/1, BSP PL, JIS B0202, G1/4 and G 1/2 etc.
  • BSP - British standard straight pipe thread - British Standard BS21.
UNS

Unified Special Pitch Threads

Applicable Standards

  • ASME B1.1 Unified inch screw threads (UN and UNR thread form)..
  • Screw thread standards for federal services SEC3.
UNJ

Unified Controlled Root Radius Threads

Applicable Standards

  • ANSI B1.15 Unified inch screw threads (UNJ thread form).
  • FED-STD-H28/4 Screw thread standards for federal services section 4 controlled radius root screw threads, UNJ symbol.

Metric Thread Standards

M

M - metric Screw Thread M profile.

Applicable Standards

  • ISO 261 ISO General Purpose metric Screw Threads - general Plan.
  • ASME B1.13M metric Screw Threads M profile.
  • FED-STD-H28/1 metric screw threads.
M Keg metric Taper Threads

Mainly used in Germany.

Applicable Standards

  • DIN 158-1 Metric external taper screw threads and mating internal parallel screw threads - Part 1. Nominal sizes, limit deviations, limits of size and verification.
  • DIN 158-2 metric external taper screw thread and mating internal parallel screw threads - Part 2. gauging system, use of gauges, calculation of gauge dimensions and general features.

BSi : British Standards

Japanese Standards.

PN Flanges

BS4504 PN16 Flange Dimensions

DN=Nominal Size, D=Outside Diameter, A Outside diameter of neck, B1=Bore of type 101 & 112 Flange, C1=Thickness of weld neck and boss flange, N1=Diameter of weld neck, N2=diameter of boss, R=corner radius, H1=length of boss flange, H2=Length of weld neck flange, H3=length of neck.

Note: The flanges shown are only are small part of the range covered by BS4504.

The facings shown are type B (RF - Raised Face) Other facings include Type A Flat, Type C Tongue, Type D Groove, Type E Spigot, Type F Recess, Type G O Ring Recess and Type H O ring Groove.

All PN16 Flange Dimensions are in (mm)

DN D C1 C2 H1 H2 H3 R A N1 N2 B1 d1 f1 DN mm K mm L mm No Size mm
10 90 14 14 20 35 6 3 17,2 28 30 18 40 2 10 60 14 4 M12
15 95 14 14 20 35 6 3 21,3 32 35 22 45 2 15 65 14 4 M12
20 105 14 14 24 38 6 4 26,9 39 45 27,5 58 2 20 75 14 4 M12
25 115 16 16 24 38 6 4 33,7 46 52 34,5 68 2 25 85 14 4 M12
32 140 18 16 26 40 6 5 42,4 56 60 43,5 78 2 32 100 18 4 M16
40 150 18 16 26 42 7 5 48,3 64 70 49,5 88 3 40 110 18 4 M16
50 165 20 18 28 45 8 5 60,3 74 84 61,5 102 3 50 125 18 4 M16
65 185 20 18 32 45 10 6 76,1 92 104 77,5 122 3 65 145 18 8 M16
80 200 20 20 34 50 10 6 88,9 110 118 90,5 138 3 80 160 18 8 M16
100 220 22 20 40 52 12 6 114,3 130 140 116 162 3 100 180 18 8 M16
125 250 22 22 44 55 12 6 139,7 158 168 141,5 188 3 125 210 18 8 M16
150 285 24 22 44 55 12 8 168,3 184 195 170,5 212 3 150 240 22 8 M20
200 340 26 24 44 62 16 8 219,1 234 246 221,5 268 3 200 295 22 12 M20
250 405 29 26 46 70 16 10 273 288 298 276,5 320 3 250 355 26 12 M24
300 460 32 28 46 78 16 10 323,9 342 350 327,5 378 4 300 410 26 12 M24
350 520 35 30 57 82 16 10 355,6 390 400 359 438 4 350 470 26 16 M24
400 580 38 32 63 85 16 10 406,4 444 456 411,0 490 4 400 525 30 16 M27
450 640 42 34 68 87 16 12 457,0 490 502 462,0 550 4 450 585 30 20 M27
500 715 46 34 73 90 16 12 508,0 546 559 513,5 610 4 500 650 33 20 M30
600 840 52 36 83 95 18 12 610,0 650 658 616,5 725 5 600 770 36 20 M33
700 910 60 36 83 100 18 12 711,0 750 760 - 795 5 700 840 36 24 M33
800 1025 68 38 90 105 20 12 813,0 848 864 - 900 5 800 950 39 24 M36
900 1125 76 40 94 110 20 12 914,0 948 968 - 1000 5 900 1050 39 28 M36
1000 1255 84 42 100 120 22 12 1016,0 1056 1072 - 1115 5 1000 1170 42 28 M39
1200 1485 98 48 - 130 30 12 1220,0 1260 - - 1330 5 1200 1390 48 32 M45
1400 1685 - 52 - 145 30 12 1420,0 1465 - - 1530 5 1400 1590 48 36 M45
1600 1930 - 58 - 160 35 12 1620,0 1668 - - 1750 5 1600 1820 56 40 M52

Flange Bolts - K = bolt circle diameter (PCD), L = diameter of bolt holes in flange, No = number of bolt holes in flange, Size of bolts.

BS4504 PN40 Flange Dimensions

DN=Nominal Size, D=Outside Diameter, A Outside diameter of neck, B1=Bore of type 101 & 112 Flange, C1=Thickness of weld neck and boss flange, N1=Diameter of weld neck, N2=diameter of boss, R=corner radius, H1=length of boss flange, H2=Length of weld neck flange, H3=length of neck.

Note: The flanges shown are only are small part of the range covered by BS4504.

The facings shown are type B (RF - Raised Face) Other facings include Type A Flat, Type C Tongue, Type D Groove, Type E Spigot, Type F Recess, Type G O Ring Recess and Type H O ring Groove.

Note all dimensions in mm.

DN D C1 C2 H1 H2 H3 R A N1 N2 B1 d1 f1
10 90 14 16 22 35 6 3 17.2 28 30 18 40 2
15 95 14 16 22 38 6 3 21.3 32 35 22 45 2
20 105 16 18 26 40 6 4 26.9 40 45 27.5 58 2
25 115 16 18 28 40 6 4 33.7 46 52 34.5 68 2
32 140 18 18 30 42 6 5 42.4 56 60 43.5 78 2
40 150 18 18 32 45 7 5 48.3 64 70 49.5 88 3
50 165 20 20 34 48 8 5 60.3 74 84 61.5 102 3
65 185 22 22 38 52 10 6 76.1 92 104 77.5 122 3
80 200 24 24 40 58 12 6 88.9 110 118 90.5 138 3
100 235 26 24 44 65 12 6 114.3 134 145 116 162 3
125 270 28 26 48 68 12 6 139.7 162 170 141.5 188 3
150 300 30 28 52 75 12 8 168.3 190 200 170.5 218 3
200 375 36 34 52 88 16 8 219.1 244 260 221.5 285 3
250 450 42 38 60 105 18 10 273 306 312 276.5 345 3
300 515 48 42 67 115 18 10 323.9 362 380 327.5 410 4
350 580 54 46 72 125 20 10 355.6 408 424 359.5 465 4
400 660 60 50 78 135 20 10 406.4 462 478 411 535 4
450 685 66 50 84 135 20 12 457 500 522 462 560 4
500 755 72 52 90 140 20 12 508 562 576 513.5 615 4
600 890 84 60 100 150 20 12 610 666 686 616.5 735 5

ANSI Flanges

ANSI150Lb Flange and Bolt Dimensions according to ASME B16.5

Nominal Pipe Size NPS (inches) Diameter of Flange (inches) No. of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-1/2 4 1/2 2-3/8
3/4 3-7/8 4 1/2 2-3/4
1 4-1/4 4 1/2 3-1/8
1-1/4 4-5/8 4 1/2 3-1/2
1-1/2 5 4 1/2 3-7/8
2 6 4 5/8 4-3/4
2-1/2 7 4 5/8 5-1/2
3 7-1/2 4 5/8 6
3-1/2 8-1/2 8 5/8 7
4 9 8 5/8 7-1/2
5 10 8 3/4 8-1/2
6 11 8 3/4 9-1/2
8 13-1/2 8 3/4 11-3/4
10 16 12 7/8 14-1/4
12 19 12 7/8 17
14 21 12 1 18-3/4
16 23-1/2 16 1 21-1/4
18 25 16 1-1/8 22-3/4
20 27-1/2 20 1-1/8 25
24 32 20 1-1/4 29-1/2

ANSI300Lb Flange and Bolt Dimensions according to ASME B16.5

Nominal Pipe Size NPS (inches) Diameter of Flange (inches) No of Bolts Diameter of Bolts (inches) Bolt Circle (inches)
1/4 3-3/8 4 1/2 2-1/4
1/2 3-3/4 4 1/2 2-5/8
3/4 4-5/8 4 5/8 3-1/4
1 4-7/8 4 5/8 3-1/2
1-1/4 5-1/4 4 5/8 3-7/8
1-1/2 6-1/8 4 3/4 4-1/2
2 6-1/2 8 5/8 5
2-1/2 7-1/2 8 3/4 5-7/8
3 8-1/4 8 3/4 6-5/8
3-1/2 9 8 3/4 7-1/4
4 10 8 3/4 7-7/8
5 11 8 3/4 9-1/4
6 12-1/2 12 3/4 10-5/8
8 15 12 7/8 13
10 17-1/2 16 1 15-1/4
12 20-1/2 16 1-1/8 17-3/4
14 23 20 1-1/8 20-1/4
16 25-1/2 20 1-1/4 22-1/2
18 28 24 1-1/4 24-3/4
20 30-1/2 24 1-1/4 27
24 36 24 1-1/2 32

What are DN Flange Sizes?

DN means "Diameter Nominal" which is the rough conversion to mm (millimeters) from imperial sizes, on the basis that one inch equals 25mm. (Actually 1 inch is exacly 25.4mm but for flange sizes 25mm is the universal measurement used). See the DN size table below.

1/2" DN15 6" DN150
3/4" DN20 8" DN200
1" DN25 10" DN250
1¼" DN32 12" DN300
1½" DN40 14" DN350
2" DN50 15" DN375
2½" DN65 16" DN400
3" DN80 18" DN450
4" DN100 20" DN500
5" DN125 24" DN600

What is flange PCD?

The PCD of a flange is the most critical dimension, "Pitch Circle Diameter" being the diameter of a circle that passes through the central point of all the bolt holes. There are several flange standards used in the valve and process pipework industries, below is a guide the the most popular four flanges.

British Standard - BS10 Table D Table E Table F Table G Table H Table J Table K Table E is the most popular for applications with water. All dimensions are specified in inches.
Australian Standard - AS2129 Table C Table D Table E Table F Table G Table H Table J These flanges are equivalent to the BS10 flanges, except that all dimensions are specified in mm. In some sizes, bolt holes are slightly larger to give better clearance.
American National Standards Institute (ANSI) ANSI 125 ANSI 150 ANSI 300 ANSI 600 ANSI 900 ANSI 1500 Higher numbers denote higher pressures. Sometimes people use the word 'Class' instead of ANSI. e.g. an ANSI 150 flange might be called a 'Class 150' All dimensions are specified in inches.
British Standard - BS4504 BS4504-6 BS4504-10 BS4504-16 BS4504-25 BS4504-40 BS4504-64 BS4504-100 PN6 PN10 PN16 PN25 PN40 PN64 PN100 Engineers use the prefix PN (Pressure Nominale). e.g. a BA4504-16 flange will commonly be referred to as a PN16 Generally, a PN16 flange is designed to withstand pressures up to 16 bar. All dimensions are specified in mm.