The British standard pipe thread (BSP Thread) is a family of standard thread screw thread types. It has been adopted as in plumbing and pipe fittings except in North America and, where NPT and related threads are used.
The British standard pipe (BSP thread) is adopted as the standard in plumbing and pipe fittings. If we will say in common language for making pipe different from different places can fit together properly. It uses Sealing pipes and fitting by
Types BSP thread:
There are two main types of British standard pipe (BSP thread)
1-BSPP (British Standard Pipe Parallel)
2-BSPT (British Standard Pipe Tapered)
BSPP (British Standard Pipe Parallel): The British standard pipe parallel threads, Which have a constant diameter along the length of the thread.
BSPP fitting has a sealing o-rings and washer to create the seal between the female and male threads.
BSPT (British Standard Pipe Tapered): The British standard pipe tapered diameter increase and decrease along the length of threads. It means they become narrow as you move to the end of the fitting.
This means BSPT fitting replies on the taper to create a seal. If we say it another way the threads themselves do not provide the sealing action. It is a wedge effect to the taper that creates a tight seal.
They can be joined in two different ways.
1-Jointing threads
2-Long-screw threads
Jointing threads: These are pipe threads for joints made pressure-tight by the mating of the threads They always use taper external threads but can we have either parallel or taper internal threads.
Long-screw threads: These are parallel pipe threads used where the pressure-tight joint is achieved by the compression of a soft material on the surface of the external thread by tightening a nut against a socket.
Thread-form:
The parallel and the taper for both pipe threads. which has the following characteristics:
#Symmetrical v-thread in which the angle between the flanks is 55 degrees.
#One six months of this V is truncated at the bottom and top.
#The threads are rounded equally at the crests and roots by circular arc-lend tangentially with the flanks.
#The theoretical depth of the threads is therefore 0.64 times the nominal pitch of the relation between them.
Identify the type of thread a fitting or pipe BSP
You can visually inspect the threads and measure the diameter. British Standard Pipe Parallel (BSPP) threads will have a consistent diameter along the threads, while British Standard Pipe taper (BSPT). It is also common to see markings on the fittings indicate whether they are British Standard Pipe Parallel (BSPP) or British Standard Pipe taper (BSPT).
It is important to note that there is a difference between the nominal size of the British Standard Pipe (BSP) thread and it is the original diameter. The nominal size refers to the size position of the thread while the actual dimension takes into score the pitch and tapers.
You can see difference between male and female threads.
( Measurement size chart BSP )
| Dash Size | Size (inches) | TPI | Male O/D (mm) | Female I/D (mm) | Hex |
| -2 | 1⁄8 | 28 | 9.7 | 8.6 | 14 |
| -4 | 1⁄4 | 19 | 13.2 | 11.5 | 19 |
| -6 | 3⁄8 | 19 | 16.7 | 14.9 | 22 |
| -8 | 1⁄2 | 14 | 20.9 | 18.6 | 27 |
| -10 | 5⁄8 | 14 | 22.9 | 20.6 | 30 |
| -12 | 3⁄4 | 14 | 26.4 | 24.1 | 32 |
| -16 | 1 | 11 | 33.2 | 30.3 | 41 |
| -20 | 1 1⁄4 | 11 | 41.9 | 38.9 | 50 |
| -24 | 1 1⁄2 | 11 | 47.8 | 44.9 | 60 |
| -32 | 2 | 11 | 59.6 | 56.7 | 70 |
Let’s walk through a practical example to help you identify BSPP and BSPT threads:
Imagine you have two pipe fittings, and you need to determine whether they have BSPP or BSPT threads.
1-Visual Inspection:
Fitting A: The threads on Fitting a look parallel, maintaining the same diameter along their length.
Fitting B: The threads on Fitting B appear to narrow towards one end.
Identification:
Fitting A: It is likely British Standard Pipe Parallel (BSPP) because the threads are straight and parallel.
Fitting B: It is likely British Standard Pipe taper (BSPT) due to the tapering or narrowing of the threads.
2-Sealing Mechanism:
Fitting A: Upon closer inspection you notice a rubber washer between the male and female threads.
Fitting B: There is no additional washer the taper of the threads seems to create a natural seal.
Identification:
Fitting A: Confirms British Standard Pipe Parallel (BSPP) as it uses a sealing washer.
Fitting B: Confirms British Standard Pipe taper (BSPT) relying on the taper for sealing.
3-Check for Markings:
Fitting A: You find a label indicating British Standard Pipe Parallel (BSPP) on Fitting A.
Fitting B: No specific label is found, but based on the visual characteristics, it aligns with the British Standard Pipe Taper (BSPT).
Identification:
Fitting A: Confirmed as British Standard Pipe Parallel (BSPP) with the labeling.
Fitting B: Likely British Standard Pipe taper (BSPT) based on visual characteristics.
4-Measurement:
Fitting A: Measure the diameter using a caliper, considering the pitch and taper.
Fitting B: Similar measurement for confirmation.
Identification:
Fitting A: The British Standard Pipe Parallel (BSPP) Measurement aligns.
Fitting B: The British Standard Pipe Taper (BSPT) Measurement supports the tapered.
Application:
BSPT: The British standard pipe taper used in particularly in hydraulic and pneumatic systems for high-pressure applications.
BSPP: The British standard pipe parallel is used in low-pressure applications where a reliable seal is required like water and pneumatics systems.
Thread angle :
BSPT: The British standard pipe taper the thread angle is 60 degrees.
BSPP: The British standard pipe parallel to the thread angle is 55 degrees.
Thread directions:
BSPT: The British standard pipe taper both the female threads and male threads are parallel.
BSPP: The British standard pipe parallel the female threads is parallel while the male thread is taper.
Tools and Techniques:
Visual Inspection: The visual inspection is a basic method for knows BSPP and BSPT threds.The taper threads will slowly slowly decrease in diameter but the parallel threads will maintain a relevant diameter.
Calipers and Micrometers: The calipers and micrometers tools are useful for measuring threads diameters and measuring the outer diameters and inner diameters can provide valuable information.
Thread Gauges:The thread gauge is a indispensable tools for accuracy identify threads. A gauge that matches the thread profile confirms the thread type.
FAQs:
1-What is full-form BSP?
Answer: British standard pipe.
2-What are the main types of BSP threads?
Answer: Two main types of BSP thread first one is BSPP (British standard pipe parallel) and the second one is BSPT (British standard pipe taper).
3-How do I identify BSPT and BSPP threads?
Answer: British standard taper (BSPT) threads are taper narrow toward the end.While British standard pipe parallel (BSPP) thread is parallel maintains a consistent diameter.
4-What is the difference between BSPT and BSPP threads?
Answer: The main difference is the shape of the thread as you know BSPT threads are tapers and BSPP are parallel threads, BSPT fitting rely on the taper for sealing but BSPP typically uses a sealing o-ring and washer.
5-How do I measure BSP thread size?
Answer: First check the diameter of the threads using caliper and see the BSP thread size are nominal and then actual dimensions take into account the pitch and taper.
Conclusion
We hope that we have cleared all yours questions about BSP threads .If you have any queries about the “BSP THREAD” you can contact directly in my contact us page. Thanks for reading.
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