Syphons

Syphons are pressure gauge accessories used to help protect instruments from high-temperature media such as steam. They are fitted between the process connection and the gauge to allow condensate to form, reducing direct exposure to heat during pressure measurement.

The range includes U tube, U style, ring and pig tail options for industrial installations using BSP connections. Select the appropriate gauge syphon by checking thread compatibility, orientation, available space and whether additional pressure gauge fittings such as isolation valves or adaptors are required.

Gauge syphon selection

Syphons are pressure gauge accessories used where the process temperature may otherwise damage the measuring instrument. They are commonly fitted between the process connection and the gauge to help create a condensate barrier, reducing direct exposure to high-temperature media such as steam.

Typical forms include U tube, U style, ring and pig tail configurations. The correct type depends on the installation layout, available space, gauge orientation and how the impulse line is arranged. BSP connection requirements should be checked against the gauge, valve and process connection before ordering.

For maintenance teams, OEMs and plant engineers, gauge syphons are often selected as replacement accessories for existing steam services or specified as part of a new pressure gauge installation. Consider the process media, temperature conditions, connection compatibility and whether additional accessories such as isolation valves or adaptors are required.

Temperature protection

Gauge syphons help protect pressure instruments from direct exposure to high-temperature media by allowing condensate to form between the process and the gauge.

Installation formats

U tube, U style, ring and pig tail arrangements support different mounting layouts, gauge positions and pipework configurations.

BSP compatibility

BSP sizing should be matched to the gauge, valve, adaptor or process connection to support a secure and compatible installation.

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Typical applications

Gauge syphons are used in industrial pressure measurement where temperature, installation layout and instrument protection need to be considered.

Steam pressure indication

Used between steam services and pressure gauges to help reduce the effect of direct high-temperature exposure on the instrument.

Boiler plant maintenance

Suitable for replacement and maintenance stock where pressure gauges are installed on boiler-related pipework and associated systems.

OEM equipment builds

Specified by OEMs as part of pressure gauge assemblies where a gauge requires separation from elevated process temperatures.

Process pipework installations

Used in plant pipework where gauge orientation, BSP connection compatibility and available installation space influence accessory selection.

How to choose

Select a gauge syphon by checking the process conditions, connection type, installation layout and the accessories used with the pressure gauge.

Match the connection

Confirm the BSP size and thread compatibility with the pressure gauge, isolation valve, adaptor or process tapping before fitting.

Check media temperature

Use a gauge syphon where the gauge needs protection from high-temperature media such as steam, subject to the suitability of the full installation.

Consider the shape

U tube, U style, ring and pig tail forms suit different orientations, clearances and mounting arrangements around the gauge.

Review the full assembly

Consider whether isolation valves, gauge adaptors, sealing washers or mounting accessories are also needed for maintenance and installation compatibility.

Gauge syphon FAQs

These answers cover common selection and installation questions for pressure gauge syphons used in industrial applications.

What is a pressure gauge syphon used for?

A pressure gauge syphon is fitted between the process and the gauge to help protect the instrument from high-temperature media, particularly steam, by allowing condensate to form in the line.

What is the difference between U tube, ring and pig tail syphons?

The main difference is the shape and installation layout. U tube, ring and pig tail designs are chosen according to available space, gauge orientation and pipework arrangement.

Do I need an isolation valve with a gauge syphon?

An isolation valve is often used with pressure gauges to allow safer maintenance or replacement, but the correct arrangement depends on the process and site requirements.

How do I check if a syphon will fit my gauge?

Check the thread type, BSP size, gauge connection orientation and any additional fittings such as valves or adaptors. The full assembly must be compatible before installation.