Technical
154
Dixon Fire 2014
US: 877.712.6179 Canada: 800.786.9697 • dixonvalve.com
Technical
P
Thread Chart
National
Standard
NH*
Straight
Iron Pipe
NPSH
New York
Corporation
NYCT
Pacific Coast
PCT
New York
Fire Dept.
NYFT
Chemical
Hose
CHT *
NH
Underwriter's
Play Pipe
PPS
Garden
Hose
GHT *
Chicago Fire
Dept.
(
NEW) *
Chicago Hose
Size ODM TPI
ODM TPI
ODM TPI
ODM TPI
ODM TPI
ODM TPI
ODM TPI
ODM TPI
ODM TPI
ODM TPI
¾"
1"
1¼"
1½"
2"
2½"
3"
3½"
4"
4½"
5"
6"
1.375
1.375
1.6718
1.990
2.5156
3.0686
3.6239
4.2439
5.0109
5.7609
6.260
7.025
8
8
9
9
8
7½
6
6
4
4
4
4
1.0353 *
1.2951 *
1.6399 *
1.8788 *
2.3528 *
2.841 *
3.470
3.970
4.470
4.970
5.530
6.590
14
11½
11½
11½
11½
8
8
8
8
8
8
8
--
--
--
2.093
2.547
3.000
--
--
--
--
--
--
--
--
--
11
11
8
--
--
--
--
--
--
1.0625
1.3125
1.860
2.100
2.550
3.035
--
--
5.000
--
--
--
11
11½
11
11
10
7½
--
--
4
--
--
--
--
1.660
--
2.100
--
3.030
3.630
4.070
4.610
5.800
--
--
--
8
--
8
--
8
8
8
8
4
--
--
1.375
1.370
--
--
--
--
--
--
--
--
--
--
8
8
--
--
--
--
--
--
--
--
--
--
--
--
--
2.1875
--
--
--
--
--
--
--
--
--
--
--
12
--
--
--
--
--
--
--
--
1.0625
1.0625
--
--
--
--
--
--
--
--
--
--
11½
11½
--
--
--
--
--
--
--
--
--
--
--
--
--
1.933
--
2.990
--
--
--
--
--
--
--
--
--
11½
--
7½
--
--
--
--
--
--
1.081
1.2951
1.705
1.946
2.522
3.043
--
--
--
--
--
--
11½
11½
11½
11½
8
7
--
--
--
--
--
--
National )orm Thread $EEreviation for tapered iron pipe thread is T,PT or NPT (National Pipe Tapered)
2'0 2
utside 'iameter of 0ale
B Threads are designed to connect with Eoth B&T and $0$ fittings
(/
isted are the more popular thread types other threads types are availaEle please contact 'ixon for more information)
Thread Legend
,
nitials
&
ommon Name
Dixon Suffix
5
egion Normally 8sed
2 1 2" 2'0
1
2 1 2"
TP,
2
$0$ B&T $lEerta 0utual $id British &olumEia Thread
B*
British &olumEia $lEerta
&
S$
&
anadian Standard $ssociation
C
2
ntario
12
5
NS1
Nova Scotia 1
NS
Nova Scotia
2
5
QST Q0T
QueEec Standard Thread
Q
QueEec
1
:&
T
:
estern &anada Thread
W
SasNatchewan 0anitoEa
2
6
GHT
Garden Hose Thread
G
North $merica
1
outside diameter of male
2
threads per inch
NPS
National Pipe Straight
S
NPT
National Pipe Tapered
T
NST (NH)
National Standard Thread
F
0
ost of 8S$
N<&
New <orN &orporation
NYC
NewarN N-
N<)'
New <orN )ire 'epartment
NYFD
New <orN )ire 'epartment
Fire Threads
:
ithin North $merica there are many regional fire threads the most popular Eeing the "NST" (or "NH") thread which is the
predominant 8S$ fire thread The NST thread is sometimes used in &anada especially in sizes " and larger
:
ithin &anada the most common threads used for fire applications are
•
1" 1½" 2"
sizes use NPS (National Pipe Straight) thread
•
2½"
each region uses different threads please see the taEle Eelow
•
"
and larger NST threads are often used
Before ordering please confirm the type of thread required Thread requirements change Ey region