BSPP
BSPP is an acronym that represents British Standard Parallel Pipe. It is one of the widely accepted standards used to connect pipes and pipes fittings by joining the male thread with the female thread. The male thread is placed on the external body while the female is internal. So, it means the external and internal parts are connected to form an assembly of pipes and flanges. As widely accepted as BSPP is, it is not accepted in some countries such as North America. BSPP standards cover various sizes and are available in different types. BSPP connection uses a bonded seal ring or Dowty seal to form the sealing.
1. What is BSPP ?
BSPP is also known as British Standard Parallel Pipe is the internationally accepted standard mostly used in Europe, Australia, UK, and Asian countries. They are the specifications given to be used for the reliable connection of pipes and flanges. BSPP is labeled as “G”. The BSPP type comes with a female and male thread which is placed internally and externally during connection to form the perfect connection. Also, the BSPP uses a bonded seal ring as the sealing type for the connection. The standard has been adopted by many countries as the standard to be used for pipe connection. BSPP threads are designed to perfectly withstand high pressure and temperature. More so, they are available in various sizes to fit different purposes.
2. What are the dimensions of BSPP?
BSPP threads are available for different sizes as shown in the table below:
3. What are the differences between NPT and BSPP?
NPT and BSPP are ancient pipe thread standards used for the connection of different pipe sizes. NPT represents National Pipe Thread and it is dominantly used in the United States as their basic specification. They are applied for both straight and tapered thread used in various industries. Both BSPP and NPT have similar functions, however, there are points of diversification which are listed below:
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Though they have similar peaks and valleys, the designs are different. The peaks and valley for NPT threads are flat while it is round in BSPP.
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The thread angle for NPT is 60 degrees while it is 55 degrees for BSPP thread.
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NPT threads are dominantly used in oil and gas industries while BSPP threads are applied in other pressure system applications.
A common question while talking about BSPP and NPT threads is whether or not they can be used together. It is not recommended to mix their threads during connection as it could result in leakage of process fluids and other damages during operation. To explain this, the NPT threads are designed in a way to get connected tightly without any sealant while the BSPP threads are used with ring bond sealant. Therefore, if the sealants are not used for the BSPP thread or used with the NPT thread, you can picture the adverse effect it will have on the system.
4. How can you measure the BSPP thread ?
One of the most important parts of a connection is to determine and properly measure the right size for the pipe threads. However, many have found it quite tasking to carry out. Not to worry, simply follow these steps to guide your measurement:
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Firstly, determine the thread is whether tapered or parallel thread by measuring the fourth/fifth and last full thread. If the female thread outer diameter increases from the first thread to the last thread or decreases from the first thread to the last thread, the thread is under a group of tapered. If the diameter stays equal from the first to last thread, it is a parallel thread.
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Next, with the use of a ruler or vernier gauge, measure the external part of the male thread or female thread. The measurement should be done across the outer part.
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After the measurement, subtract 1/4 (0.25) from the outer diameter measured. For example, when the outer diameter measures 1”, after subtracting 1/4” you’ll get 3/4”. This is the figure for the pipe thread size. From the table showing the dimensions of the BSPP thread, the 3/4” can also be 12 dash size.
BSPP thread follows the standards of ISO 228 and incorporates the Whitworth standard threads for use. They are used majorly in plumbing industries around the world, however, asides from this, they are applied in other industries such as gas and oil, power plants, manufacturing, chemical industries, etc.