Pressure and vacuum instrumentation is generally supplied with either BSP (British Standard Pipe) or NPT (National Pipe Thread). BSP is mostly supplied in a parallel configuration so the pressure tight seal is made using a sealing washer. The choice of the sealing washer material depends on the pressure and the medium being used. In addition a tapered BSP thread is also available. NPT Threads are always tapered so the pressure tight seal is made on the threads. Sealing tape such as PTFE can also be used.
BSP Process Connections - BSP (British Standard Pipe) - Parallel:
BSP is the most common process connection in the UK. It is a parallel thread so the pressure tight seal is made using a sealing washer. The choice of the sealing washer material depends on the pressure and the medium being used. The most commonly used sizes are 1/8, 1/4, 3/8 and 1/2 inch BSP. Details including physical sizing and TPI (Threads per Inch) are below. If you require information on an alternative BSP connection size please contact us.
This information page provides details on the standard range of BSP connections, 1/8″, 1/4″, 3/8″ and 1/2″ .We can also supply other BSP sized threads please contact us.
1/8″ BSP process connections are most commonly used on Small Diameter Gauges but can also be used with other gauge sizes and are recommended for use with pressures upto 400 bar (5800 psi). External Thread Diameter: 9.5mm Pitch: 27 threads per inch (TPI) 1/8” and 1/4” BSP Threads may or may not have a spigot, it is not a requirement of BS EN 837-1.3/8″ BSP process connections can be used with most Pressure and Vacuum gauges and are recommended for use with pressures upto 600 bar (8700 psi) if the connection material is brass, with a stainless steel connection the range can increase to 1000 bar (14500 psi). External Thread Diameter: 16.5mm Pitch: 19 Threads Per Inch (TPI) 1/2″ BSP process connections can be used with most Pressure and Vacuum gauges and are recommended for use with pressures upto 1000 bar (14500 psi) if the connection material is brass, with a stainless steel connection the range can increase to 1600 bar (23200 psi). External Thread Diameter: 21mm Pitch: 14 Threads Per Inch (TPI) 1/4″ BSP process connections are most commonly used on Small Diameter Gauges but can also be used with other gauge sizes and are recommended for use with pressures upto 600 bar (8700 psi) if the connection material is brass, with a stainless steel connection the range can increase to 1000 bar (14500 psi). External Thread Diameter: 13.15mm Pitch: 19 Threads Per Inch (TPI) 1/8” and 1/4” BSP Threads may or may not have a spigot, it is not a requirement of BS EN 837-1.
NPT Process Connections - NPT (National Pipe Thread) - Tapered:
NPT is the most common process connection in the USA and in the oil and petroleum industries. It is a tapered thread so the pressure tight seal is made on the thread itself. The most commonly used sizes are 1/8, 1/4, 3/8 and 1/2 inch NPT. Details including physical sizing and TPI (Threads Per Inch) are below. If you require information on an alternative NPT connection size please contact us.
This information page provides details on the standard range of NPT connections, 1/8″, 1/4″, 3/8″ and 1/2″. We can also supply other NPT sized threads, please contact us.
1/2″ NPT process connections can be used with most Pressure and Vacuum gauges and are recommended for use with pressures upto 1000 bar (14500 psi) if the connection material is brass, with a stainless steel connection the range can increase to 1600 bar (23200 psi). External Thread Diameter: 21mm (bottom of thread) Pitch: 14 Threads Per Inch (TPI) 1/8″ NPT process connections are most commonly used on Small Diameter Gauges but can also be used with other gauge sizes and are recommended for use with pressures upto 400 bar (5800 psi). External Thread Diameter: 18mm (bottom of thread) Pitch: 27 Threads Per Inch (TPI) 3/8″ NPT process connections can be used with most Pressure and Vacuum gauges and are recommended for use with pressures upto 600 bar (8700 psi) if the connection material is brass, with a stainless steel connection the range can increase to 1000 bar (14500 psi). External Thread Diameter: 18mm (bottom of thread) Pitch: 18 Threads Per Inch (TPI) 1/4″ NPT process connections are most commonly used on Small Diameter Gauges but can also be used with other gauge sizes and are recommended for use with pressures upto 600 bar (8700 psi) if the connection material is brass, with a stainless steel connection the range can increase to 1000 bar (14500 psi). External Thread Diameter: 13mm (bottom of thread) Pitch: 18 Threads Per Inch (TPI)
BSP Tapered Process Connections - BSP (British Standard Pipe) - Tapered:
BSPT is not commonly used with pressure and vacuum instrumentation, we are however able to provide gauges with BSPT connections. It is a tapered thread so the pressure tight seal is made on the thread itself. The most commonly used sizes are 1/8, 1/4, 3/8 and 1/2 inch BSPT. If you require information on BSPT connection sizes please contact us.
You can also download our fully detailed Process Connection Data Sheet.
The instrument simply connects directly to the application by the threaded process connectionThe instrument simply connects directly to the application by the threaded process connection at the lower rear of the gaugeThe instrument simply connects directly to the application by the threaded process connection at the center rear of the gaugThe instrument simply connects directly to the application by the threaded process connection at the centre rear of the gauge, a 3 hole front flange is included to enable fitment into a panel etc. using fixings from the front of the gauge – does not require access to the rear to fit. The instrument simply connects directly to the application by the threaded process connection at the lower rear of the gauge, a 3 hole front flange is included to enable fitment into a panel etc. using fixings from the front of the gauge – does not require access to the rear to fit. The instrument simply connects directly to the application by the threaded process connection at the Centre rear of the gauge, a rear clamp is included to enable fitment into a panel etc. using fixings from the rear of the gauge – this method of fitment gives a clean looking finish with no connections on the front of the gauge. The instrument simply connects directly to the application by the threaded process connection at the lower rear of the gauge, a rear clamp is included to enable fitment into a panel etc. using fixings from the rear of the gauge – this method of fitment gives a clean looking finish with no connections on the front of the gauge. Connects directly to the application using the threaded connection but also features a rear flange to enable a secure connection to a panal etc.
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