BPT Adapter (Bridgeport??)

[Medic1781]

Did Bridgeport ever have its own fire hose thread?

I have a coupling adapter marked NST to BPT.

The NST is obviously National Standard Thread and fits accordingly.
While the BPT is a bit different. (3.180x8)

Any idea on what its used for?
History on such piece?

Thanks
Medic1781

[Catch22]

Are you sure it's not British Pipe Thread?

[rickyr]

BPT = British Pipe Thread

[Medic1781]

Its not British
Thats BSP or BSPT
British Standard Pipe Thread

[CaptOldTimer]

Did Bridgeport ever have its own fire hose thread?

I have a coupling adapter marked NST to BPT.

The NST is obviously National Standard Thread and fits accordingly.
While the BPT is a bit different. (3.180x8)

Any idea on what its used for?
History on such piece?

Thanks
Medic1781

They probably did as did other cities, towns, counties.

NYF – New York Fire Dept. Thread 1½" (2.100 ODM x 8 tpi) 2½" (3.030 ODM x 8 tpi)
CF - Chicago Fire Dept. Thread 1½" (1.933 ODM x 11.5 tpi) 2½" (2.990 ODM x 7.5 tpi)
NYC – New York Corporation Thread 1½" (2.093 ODM x 11 tpi) 2½" (3.000 ODM x 8 tpi)


Personal Special Thread Table

There are well over a hundred special threads in use on fire equipment in the USA.


If you are unable to determine the threads you need:

•Contact the Fire Department or Fire Marshal responsible for the area where the equipment will be located.
•Request the threads required for fire hose connections in that area consistent with your requirements. (usually 1½" and 2½")

Always indicate the HOSE THREAD required when ordering!


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Thread Compatibility

Abbreviation System Name Compatibility Seal Method
BSPP British Standard Pipe Parallel Male BSPP with Female BSPP
Female BSPP with Male BSPP
Female BSPP with Male BSPTr Washer
Washer
Washer
BSPTr British Standard Pipe Taper Male BSPTr with Female BSPTr
Male BSPTr with Female BSPP
Female BSPTr with Male BSPTr
Female BSPTr not compatible with Male BSPP Thread
Washer
Thread
CHT American Standard Fire Hose Thread (1" National Hose Thread is Chemical Hose Thread, also known as Booster Hose Thread) 1" Male NH (NST) with 1" Female NH (NST)
1"Female NH (NST) with 1" Male NH (NST)
1" Thread is used on both ¾" hose and 1" hose.
Not compatible with other systems Washer
Washer
GHT Garden Hose Thread Male GHT with Female GHT
Female GHT with Male GHT
Thread is same for all size hose
Not compatible with other systems Washer
Washer
IPS Iron Pipe Straight Thread Generic Name for Straight Pipe Thread
See NPSH for compatibility Washer
IPT Iron Pipe Thread Generic Name for All Pipe Thread
More information required
NH or NST American Standard Fire Hose Coupling Thread (National Hose thread also known as National Standard Thread) Male NH (NST) with Female NH (NST)
Female NH (NST) with Male NH (NST)
Not compatible with other systems
Thread pitch and diameters of fire threads may vary according to local and municipal regulations. Washer
Washer
NPT American Standard Taper Pipe Thread
(National Pipe Tapered) Male NPT with Female NPT
Male NPT with Female NPTF
Male NPT with Female NPSM
Male NPT with Female NPSH
Female NPT with Male NPT
Female NPT with Male NPTF
Female NPT not compatible with Male NPSM or Male NPSH Thread
Thread
Washer
Washer
Thread
Thread
NPTF American Standard Taper Pipe Fuel Dryseal Thread (National Pipe Tapered Fine) Male NPTF with Female NPTF
Male NPTF with Female NPT
Male NPTF with Female NPSM
Male NPTF with Female NPSH
Female NPTF with Male NPTF
Female NPTF with Male NPT
Female NPTF with Male NPSM or NPSH
Note: NPTF with NPTF threads do not require sealant for the initial use. After that, sealant is required. Thread
Thread
Washer
Washer
Thread
Thread
Not Compatible
NPSH American Standard Straight Pipe for Hose Couplings (National Pipe Straight Hose) Male NPSH with Female NPSH
Female NPSH with Male NPSH
Female NPSH with Male NPT
Female NPSH with Male NPTF
Female NPSH with Male NPSM Washer
Washer
Washer
Washer
Washer
NPSM American Standard Straight Mechanical Joints (National Pipe Straight Mechanical) Male NPSM with Female NPSM
Male NPSM with Female NPSH
Female NPSM with Male NPSM
Female NPSM with Male NPT
Female NPSM with Male NPTF Seal can be either mechanical or washer.
Mating fittings must be of same type.
SIPT Straight Iron Pipe Thread Generic name for Straight Pipe Thread Washer
TIPT Tapered Iron Pipe Thread Generic name for Tapered Pipe Thread Thread



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Thread Dimensions
Nominal Dimensions of Standard Threads

ODM -- Outside Diameter of the Male IDF -- Inside Diameter of the Female TPI -- Threads per Inch


GHT (3/4") -- 1.0625 ODM, 11-1/2 TPI

NOTE: Female NPT (Tapered Pipe) thread is not available on hose swivel nuts.


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Special Thread Information
2½" thread


threads per inch 6 7 7½ 8
outside diameter of male 3.058 3.125 2.990 (Chicago) 2.841 (NPSH)
3.062 (Pittsburgh) 3.052 (NST) 3.000 (NY Corp)
3.093 3.125 (Detroit) 3.3031 (NYFD)
3.125 3.062
3.156 3.076 (Cleveland)
3.187 3.093
3.234 3.140
3.250 3.156
3.312 3.312

[Medic1781]

Figured it out after several phone calls.

Bridgeport did have its own standard until about 20 years ago when they switched over to NST. Some of the older hydrants in the city have the old BPT so they still need adapters.

[TCFD12]

We still use BPT thread for all 2-1/2" and 3" couplings. All of our hydrants, Fire department connections and standpipe connections are this thread.

And the technical spec for the thread is 3.156 X 8 TPI.

I was unaware that BPT fire changed to NST.

[Leroy140]

Medic, I can further enlighten you to this adapter. As stated, for years the Bridgeport, CT FD had it's own thread, as well as some surrounding departments, mine included, (Fairfield, CT). Trumbull and Stratford used this thread as well, but I don't know if they switched or are switching. It only applies to the 2-1/2 threads on 2-1/2 and 3 inch hose. Although we switched over to NST approx. 15 years ago, we still carry 2 adapters for each application, actually 3 of 1 and 2 of the other. 3 NST females to BPT males, one on or near our back steps on some of our rigs, and 2 BPT to NSTs. Also all of our high rise/stand-pipe bags have a BPT-NST. As a result of the switch to NST, we now have some hydrants with 2-1/2 BPT thread with 4" steamers, and some with 2-1/2 NST with 4-1/2 NST steamer threads. We keep a 4" female to 4-1/2 inch male on the female side of our hydrant elbow, and remove the adapter if the plug is NST when we lay in. The hydrants are differentiated by the color of the bonnet. As the hydrants are replaced, they are replaced with the NST hydrants. The reason? I was told cost, as it more expensive to have hydrants and couplings made special with BPT thread, so we are changing over. We still need the adapters because the majority of our FD connections are female BPT thread, although newer construction is 5" Storz connections. Standpipe outlets, etc. are still BPT, so we need the adapters there as well. Mutual aid may also require an adapter, although it would be pretty rare. Confused? I hope this clears it up a little for you.