AS-Schneider Gauge Syphons are used to protect the pressure gauge from the effect of hot pressure media such as steam and also to reduce the effect of rapid pressure surges. The syphon allows condensate to form and be collected inside the syphon, preventing the hot media (hot vapors, not just steam) from coming in direct contact with the pressure instrument. Also used as freeze protector when used with proper fill fluids. The Coil Syphon is normally used for vertical installations. The Standard Syphons are designed, manufactured and tested according to DIN 16282. The standard pipe dimension is Ø 20 x 2.6 mm. 1/2" pipe (Ø 21.3 mm) dimensions are also available. AS-Schneider is also providing so-called Commercial Style Syphons. These types have a standard pipe dimension of Ø 21.3 x 3.2 mm – using threaded pipe connections instead of weld fittings. The max. allowable (Working) Pressure (PS), as standard, is 160 bar (2,321 psi), however, depends on the wall thickness of the pipes used.
 Datasheet |
AS-Schneider Gauge Syphons are used to protect the pressure gauge from the effect of hot pressure media such as steam and also to reduce the effect of rapid pressure surges. The syphon allows condensate to form and be collected inside the syphon, preventing the hot media (hot vapors, not just steam) from coming in direct contact with the pressure instrument. Also used as freeze protector when used with proper fill fluids. The Compact Gauge Syphon can be used instead of the Coil Syphon for vertical installations. The Compact Gauge Syphon is available as Standard Type and also as Integral Snubber Type. The max. allowable (Working) Pressure (PS), as standard, is 420 bar (6,092 psi).
| Datasheet |
AS-Schneider Staright Pipes and 90° Elbows are used when gauge syphons are not necessary due to the service conditions. The Straight Pipe is used for vertical installations. The 90° Elbow is used for horizontal installations. The standard pipe dimension is Ø 20 x 2.6 mm. 1/2" pipe (Ø 21.3 mm) dimensions are also available. Max. allowable (Working) Pressure (PS) please see below Pressure / Temperature Rating which is based on the standard pipe dimension.
| Datasheet |
AS-Schneider Gauge Syphons are used to protect the pressure gauge from the effect of hot pressure media such as steam and also to reduce the effect of rapid pressure surges. The syphon allows condensate to form and be collected inside the syphon, preventing the hot media (hot vapors, not just steam) from coming in direct contact with the pressure instrument. Also used as freeze protector when used with proper fill fluids. The U Type Syphon is normally used for horizontal installations. The Standard Syphons are designed, manufactured and tested according to DIN 16282. The standard pipe dimension is Ø 20 x 2.6 mm. 1/2" pipe (Ø 21.3 mm) dimensions are also available. AS-Schneider is also providing so-called Commercial Style Syphons. These types have a standard pipe dimension of Ø 21.3 x 3.2 mm – using threaded pipe connections instead of weld fittings. The max. allowable (Working) Pressure (PS), as standard, is 160 bar (2,321 psi), however, depends on the wall thickness of the pipes used.
| Datasheet |
Surge Dampening Pipes (Water Column Pipes) by Armaturenfabrik Franz Schneider GmbH + Co. KG
Surge dampening pipes, often referred to as water column pipes, from Armaturenfabrik Franz Schneider GmbH + Co. KG are protective components used in pressure measurement lines to cushion pressure spikes and dynamic loads before they reach a pressure instrument such as a gauge, pressure transmitter or differential pressure sensor. These pipes are installed ahead of the measuring device and provide additional volume to absorb short-term pressure surges, improving instrument protection.
Water column pipes are especially useful in processes where rapid pressure changes, pulsations or abrupt valve switching occur. They help stabilize the pressure signal, extend instrument life and improve the reliability of the measurement point.
Frequently Asked Questions about Water Column (Surge Dampening) Pipes
What is a water column pipe?
A water column pipe is a length of pipe with increased internal volume installed in a measurement line to absorb and dampen sudden pressure spikes before they reach the instrument.
Where are these pipes used?
They are used in applications with rapid pressure changes, pressure pulsations or transient events where instrument protection is required.
How does a water column pipe work?
The additional volume acts as a buffer, absorbing kinetic energy from pressure fluctuations and delivering a smoother pressure signal to the instrument.
What are the benefits of using one?
They reduce pressure shocks, improve signal stability, protect instruments and increase the reliability and lifespan of measurement systems.
How is it installed?
They are installed in the measurement line directly before the instrument, with connections matching the process and instrument interface.
Which pressure ranges can they handle?
Water column pipes are available for a wide range of industrial pressures, suitable for both low and high-pressure systems.
What materials are used?
Stainless steel, steel and corrosion-resistant alloys are typical materials, providing strength and long service life.
Can they be used with different media?
Depending on the material and sealing solution, they can be used with gaseous and liquid media.
Do they improve measurement accuracy?
Yes, by damping sudden pressure changes, they improve the stability of the measured signal without introducing significant lag.
Are they maintenance-intensive?
No, they are generally low maintenance; periodic inspection is recommended to ensure leak tightness.
Can they be retrofitted?
Yes, surge dampening pipes can be retrofitted into existing systems if connections and installation space allow.
How do they support maintenance?
They protect instruments from pressure spikes, reducing potential downtime and repair frequency.
How do I choose the right water column pipe?
Consider maximum process pressure, fluctuation intensity, media and connection requirements when selecting the proper size and material.
What is the effect of pipe volume?
A larger pipe volume provides more buffering capacity and greater damping of pressure pulses.
How does temperature affect the selection?
Temperature influences material and seal selection, and components should be chosen to match operating conditions.
Can these pipes be combined with other protective devices?
Yes, they can be used together with overpressure protection devices, surge suppressors or isolation valves for comprehensive system protection.
Do they influence response time?
By smoothing pressure variations, they can deliver more stable response behaviour from the pressure instrument.
Are different installation orientations possible?
Various configurations are available to suit vertical, horizontal or compact installation spaces.