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Category Articles
How does a rigid strut take compressive load?
Added on Wed, Mar 23, 2011
Because the strut assembly consists of basically two rods joined by a structural steel member, once the strut's overall length is established, it will not change during operation. Consequently, loads applied in either direction will be... Read More
How do I use a snubber?
Added on Wed, Nov 3, 2010
The main criteria to remember when utilizing snubbers is that they are intended to be passive elements during normal operation and will become activated only when that unwanted impulse event is present. When that impulse event dissipates, the... Read More
What is a hydraulic snubber?
Added on Wed, Nov 3, 2010
A hydraulic snubber is a device that permits pipe deflection under normal operating conditions, but when subjected to an impulse load, such as an earthquake, water hammer, etc., the snubber becomes activated and acts as a rigid restraint to... Read More
What is a mechanical snubber?
Added on Wed, Nov 3, 2010
A mechanic snubber is a device that permits pipe deflection under normal operating conditions, but when subjected to an impulse load, such as an earthquake, water hammer, etc., the snubber becomes activated and acts as a rigid restraint to... Read More
How does a hydraulic snubber work?
Added on Wed, Feb 23, 2011
The basic working principal behind a hydraulic snubber is that under slow (normal) speeds, a piston moves within a hydraulic reservoir pushing hydraulic fluid from the front to the back (or visa versa) of that reservoir. When an impulse load... Read More
What is a shock suppressor?
Added on Wed, Nov 3, 2010
A shock suppressor is another name for a snubber, which is a device that permits pipe deflection under normal operating conditions, but when subjected to an impulse load, such as an earthquake, water hammer, etc., the snubber becomes activated... Read More
What are piping struts?
Added on Tue, Feb 1, 2011
Piping struts, also referred to as sway struts, are devices used to restrain movement of piping in one direction while providing for movement due to thermal expansion or contraction in another direction. Sway Struts with 3-Bolt Pipe Clamps Read More
When should I install a piping snubber?
Added on Wed, Nov 3, 2010
Because snubbers are not meant to be active support components, they could be installed at any time during the construction phase. It should also be noted that piping snubbers can be retrofit to existing systems at any time. Close Up... Read More
What are sway suppressors?
Added on Wed, Nov 3, 2010
Either sway braces or sway struts can be used to suppress swinging of the pipeline. Note that sway braces permit pipe deflection while sway struts are rigid supports meant to prevent all movement. Custom Sway Braces with Ball Joints ... Read More
What is a sway brace?
Added on Tue, Feb 1, 2011
A sway brace is a device that is recommended for controlling vibration, absorbing shock loadings, guiding or restraining the movement of pipe resulting from thermal expansion, and bracing a pipe line against sway. They contain springs that... Read More
How do you adjust a snubber?
Added on Wed, Feb 23, 2011
Snubbers can be adjusted by either changing the initial position of the telescoping cylinder or by using (where available) the adjustable rod end feature to alter the length of the snubber. Mechanical Snubber Assemblies Read More
How often do snubbers require maintenance?
Added on Wed, Mar 23, 2011
While there is no specified time interval for routine maintenance of snubber assemblies, it is recommended that an inspection of snubbers be performed on a bi-annual basis. The inspection would determine what maintenance, if any, would be... Read More
How do snubber supports work in dynamic conditions?
Added on Thu, Jun 16, 2011
Snubbers are activated when either a threshold acceleration (hydraulic snubbers) or threshold velocity (mechanical snubbers) is reached. At that point, the snubber is activated either via a valve system (hydraulic snubbers) or spring loaded... Read More
What is free stroke for a sway brace?
Added on Wed, Jun 22, 2011
Free stroke for a sway brace refers to an amount of movement which would result in no resistance. This can be established as an original factory pre-setting or can be adjusted in the field. Read More
What does a pipe snubber look like?
Added on Wed, Nov 3, 2010
This is what a pipe snubber looks like: Read More
What is a pipe snubber?
Added on Wed, Nov 3, 2010
A pipe snubber is a device that permits pipe deflection under normal operating conditions, but when subjected to an impulse load, such as an earthquake, water hammer, etc., the snubber becomes activated and acts as a rigid restraint to restrict... Read More
What do sway braces do?
Added on Wed, Nov 3, 2010
Sway braces utilize a spring coil to provide a restraint force in both a tension and compression mode. The magnitude of the restraint force is dependent upon the spring rate and the amount of deflection which will be seen during operation. ... Read More
How can I test a snubber?
Added on Wed, Nov 3, 2010
Field testing of snubbers is not recommended. In order to accurately confirm the function of a snubber, a certified test machine must be utilized to accurately simulate impulse loading. Hydraulic Snubber Being Tested on the STADAS Test... Read More
What are the ranges of motion of a hydraulic snubber?
Added on Wed, Nov 3, 2010
Hydraulic snubbers are designed with a pre-defined amount of stroke. Those stroke ratings are available in 6 inch increments from 6" to 24". The amount of movement, which could be accommodated by any stroke designation, would depend upon the... Read More
What equipment absorbs shock and resists motion in tension and compression?
Added on Wed, Jun 22, 2011
A snubber component, either hydraulic or mechanical style, can be used to restrain shock but does not absorb the shock. On the other hand, sway brace components can be used as a positive means of resisting motion in either tension or compression.... Read More
Is there a difference for drag force for hydraulic and mechanical snubber?
Added on Thu, Nov 10, 2011
There is little difference in the initial drag force associated with mechanical and hydraulic snubbers. Basically, both styles are designed to impart a maximum of 2% of their design restraint load during normal pipe deflection. Hydraulic... Read More
What is the cost comparison between mechanical and hydraulic snubbers?
Added on Thu, Nov 10, 2011
In general hydraulic snubbers are more costly than mechanical snubbers for a particular size. Hydraulic Snubbers Mechanical Snubbers Read More
What does the travel of a snubber mean?
Added on Thu, Oct 27, 2011
In reference to snubbers, the travel refers to the amount of deflection which the snubber should be able to accommodate under normal operating conditions. Note: This value must always be less than the stroke value of the snubber. Snubber Assemblies Read More
What is the criteria required to order a mechanical or hydraulic snubber?
Added on Thu, Oct 27, 2011
Please specify figure number, cylinder size, stroke, load, cold and hot piston settings, and piston end option when ordering a mechanical or hydraulic snubber. If clamp is required, please specify nominal pipe size, or special O.D. and clamp material... Read More
What is the minimum amplitude of vibration for which snubbers are effective?
Added on Wed, Nov 23, 2011
The minimum amplitude of vibration for which snubbers are effective depends on when a shock comes, how quickly it moves. For hydraulic snubbers, the standard velocity is 8" per second. Amplitude is not a function in the case of snubbers, rather the... Read More
What is the criteria to choose a mechanical or a hydraulic snubber?
Added on Thu, Oct 27, 2011
Both snubbers function similarly. One thing to consider would be the environment. If the environment is real dirty, the mechanical snubbers may get gritty and not function properly. Likewise, if the environment is extremely cold, the fluid in a... Read More
Do hydraulic snubbers require more maintenance?
Added on Thu, Nov 3, 2011
Hydraulic snubbers have a higher maintenance requirement, but can be checked to see if they are still functional, whereas mechanical snubbers have no maintenance requirements. They must simply be replaced if they quit functioning. ... Read More
What are typical errors you see when engineers specify snubbers?
Added on Thu, Nov 3, 2011
They try to use snubbers to stop vibration, they do not allow for enough stroke, the initial set position of our moving piston is incorrectly specified, and they intend to use them as a load carrying member when we must remember they are tended only... Read More
How do you predict the piping system movement? If I fail to get the correct travel and direction, will I end up damaging the snubber?
Added on Thu, Nov 3, 2011
It depends upon the system conditions, temperature, flow rate, pipe material and ambient conditions. Yes, you would damage it if you do not have proper loading of the snubber. That's why we recommend a full stress analysis of the system prior to... Read More
What typical abnormal circumstances require a snubber?
Added on Thu, Nov 10, 2011
Some typical circumstances that require a snubber are during earthquakes, wind loading, water hammer, during a pressure shock and in the actuation of safety valves. Mechanical Snubbers Read More
How do snubbers behave in wind and tornado loading?
Added on Thu, Nov 10, 2011
The direction of the load due to wind/tornado can be from any direction. However, the snubbers are aligned in the direction of the shock type force. Thus, in general, snubbers may not withstand sharp tornado forces. Hydraulic Snubbers... Read More
What are the limitations for using hydraulic vs. mechanical snubbers? Displacements? Frequencies?
Added on Wed, Nov 23, 2011
Typically, mechanical snubbers are not suitable for out door applications. Secondarily, hydraulic snubbers have more options as far as the available strokes. Frequency response and displacement wise, there is no difference between hydro/mechanical... Read More
Why are mechanical snubbers preferred for nuclear plants?
Added on Fri, Nov 25, 2011
They are favored because the hydraulic snubber contains fluid that can be degraded due to radiation, which is why mechanical snubbers are preferred. Mechanical Snubber Read More
What are hot settings, piston setting, cold settings, and pre-set of a snubber?
Added on Fri, Nov 25, 2011
Hot settings are the settings at the operating conditions. Cold settings are the settings at the installed position or start-up. The piston setting is the location of the position within the snubber at the cold position. Pre-set can refer to the... Read More
Do hydraulic snubbers have to be installed with their reservoir in any particular orientation?
Added on Thu, Oct 27, 2011
No, hydraulic snubbers do not have to be installed in any specific orientation. They can be in any position because it is a pressurized reservoir. Note: Previous generation hydraulic snubbers did require a reservoir to be oriented vertically, but the... Read More
What are the maintenance cycles on hydraulic snubbers?
Added on Fri, Nov 25, 2011
It is necessary to check the fluid levels of the hydraulic snubber once a year. Hydraulic Snubber Read More
Will a horizontal snubber allow vertical movement of pipe?
Added on Fri, Nov 25, 2011
The snubber must be oriented along the direction of the movement of the pipe during impulse loading. For horizontal pipe movement the snubber must be installed horizontally and likewise for vertical pipe movement, the snubber must be aligned in the... Read More
How much thermal movement is allowed by hydraulic snubber?
Added on Thu, Nov 10, 2011
The amount of movement that be provided by the hydraulic snubber is directly related to the stroke specifications. Please note that snubber strokes can be provided in 6" increments ranging up to 30" total. Hydraulic Snubber Read More
Based on your past experience of your snubber damage, what are the common causes?
Added on Wed, Nov 23, 2011
There are two major causes for snubber failure. The first one would be due to overloading. Snubbers may not function properly if fluid levels are low. If designed for the proper load and maintained, the snubber should not fail. Second major cause of... Read More
What is the lowest temperature a hydraulic snubber can operate?
Added on Fri, Nov 25, 2011
The lowest temperature a hydraulic snubber can operate depends on the pour point of the hydraulic fluid. This will vary according to different fluids chosen. Hydraulic Snubber Read More
If a mechanical snubber fails, can we have some locking arrangement to restrict complete imbalance and avoid major catastrophe?
Added on Fri, Nov 25, 2011
We recommend that you put a sway strut in its place. That is a temporary fix until the snubber is replaced. Large Custom Sway Struts Read More
How are mechanical snubbers different from spring hangers?
Added on Fri, Nov 25, 2011
Mechanical snubbers are shock arrestors in the event of earthquakes, pressure waves, etc. while variable spring hangers support the structure for thermal expansion or contraction. Additionally, a spring hanger is not a safety device whereas... Read More
Do mechanical snubbers need maintenance over a period of time, since there is no fluid involved?
Added on Fri, Nov 25, 2011
The mechanical snubbers do not require maintenance. Since they are sealed there should be no occurrence of jamming and the "locking" mechanism does not really lock but rather arrests the movement. Mechanical Snubbers Read More
In the case of movements in both horizontal and vertical direction would you advise to use snubber?
Added on Fri, Nov 25, 2011
Snubbers are to arrest violent and/or fast unwanted movements such as caused by an earthquake or tornado. The movements in either case would need to be arrested in the direction of the movement. Snubber Read More
Does the hydraulic fluid that is contained within the hydraulic snubber have a defined service life?
Added on Fri, Nov 25, 2011
The hydraulic fluid does not degrade; but if depleted, it will require that you add more fluid to the hydraulic snubber. Hydraulic Snubber Read More |
