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Category Articles
How do I inspect a spring support?
Added on Tue, Nov 2, 2010
Use this 10-point operational integrity check list when inspecting spring supports in the field: Beam attachment Beam attachment pin Spring hanger attachment Load flange movement Spring coil corrosion Check load indication for hot... Read More
What does the hot or cold setting mean on a variable spring support?
Added on Tue, Nov 2, 2010
The "cold" setting of a variable spring support refers to the installed position and the associated load being carried by the support at that time. The "hot" setting refers to the operating position and subsequently the associated load being ... Read More
What is a constant spring support?
Added on Tue, Nov 2, 2010
A constant spring support is a pipe support that uses a spring coil (or series of coils) to accommodate pipe movement from the initial (installed) condition to the final (operating) condition of the piping system. For all constant spring supports... Read More
What are spring cans?
Added on Tue, Nov 2, 2010
"Spring can" is the general term used to describe either variable or constant spring supports. Custom Spring Can with Slide Plates Read More
How can I size a variable spring support?
Added on Tue, Nov 2, 2010
In order to size a variable spring support, you must know the cold load, the hot load, and the amount of travel of the pipe system. From that you can determine the required spring rate, and then review the variable spring support load and travel... Read More
How much weight can a spring support?
Added on Tue, Nov 2, 2010
The maximum load that a standard variable spring can support is 50,000 lbs. The maximum load that a standard constant spring can support is 90,000 lbs. A big ton spring support can be be used for loads greater than these standards. Constant... Read More
What is the difference between a constant spring and a variable spring?
Added on Tue, Nov 2, 2010
Variable springs always must have a difference in load between the hot and cold settings. Wheras in constant springs, the load remains consistent. Additionally, in general, constant springs can provide for a higher amount of travel. ... Read More
What does the hot or cold setting mean on a constant spring support?
Added on Tue, Nov 2, 2010
The "cold" setting on a constant spring support refers to the location of the pipe at the installed position. The "hot" setting refers to the design location of the pipe at the operating position. In general, prior to installation, all spring ... Read More
How can I size a constant spring support?
Added on Tue, Nov 2, 2010
In order to size a constant spring support, you must know the load and the anticipated travel. From that you can determine the amount of total travel and then refer to the constant spring support load and travel table to locate the correct size... Read More
How does a spring pipe support work?
Added on Wed, Feb 23, 2011
In a variable spring pipe support, the spring works under the basic principal that the pipe movement will be accommodated by a compression or decompression of the spring coil. The amount of pipe movement will determine, along with the stiffness... Read More
How does a variable spring hanger work?
Added on Thu, Feb 17, 2011
Please click on the link below in order to see how a Variable Spring Hanger works: Function of a Variable Spring 7′- 6" Long Custom Variable Spring Hangers Read More
What is a spring hanger?
Added on Tue, Nov 2, 2010
A spring hanger is a subset of either variable or constant spring supports that attach directly to structural steel components and are located above the supported member. Constant Spring Hangers Read More
What is a variable spring support?
Added on Tue, Nov 2, 2010
A variable spring support is a pipe support that uses a spring coil (or series of coils) to accommodate pipe movement from the initial (installed) condition to the final (operating) condition of the piping system. For all variable spring supports ... Read More
How do I remove a spring support?
Added on Tue, Nov 2, 2010
In order to remove a spring support, first you must ensure that the spring is at its designed cold (installed) position. Next, re-install the travel stop(s) in the support. Then, provide adequate temporary support for the piping system. Once you... Read More
What are the sizes of spring supports?
Added on Tue, Nov 2, 2010
For variable springs there are 23 sizes with loads ranging from 50 lb. through 50,000 lb. For constant springs, there are 110 sizes with travel ranging from 1" to 14" and loads ranging from 0 lb. to 90,000 lb. F-Type Variable Spring... Read More
Why are variable spring rates needed?
Added on Thu, Feb 17, 2011
Variable spring rates are required so that the difference in load (which is always defined as the spring rate x movement) will match the operating conditions. Read More
When is it necessary to lock a spring support?
Added on Wed, Mar 23, 2011
Spring supports should always be locked when the load is removed at that support location. The locking prevents the stored energy of the spring coil from suddenly releasing when the spring is disconnected. Read More
Why is a variable spring support designed at the “cold” load?
Added on Thu, Feb 17, 2011
The variable spring is originally set at the "cold” load because the "cold” load implies the installed or non-operating condition of the pipeline. If a spring were able to be installed while the pipe is in full operation mode, then the spring... Read More
How do I remove travel stops in a spring hanger?
Added on Thu, Feb 17, 2011
Please click on the link of your choice of spring below, which shows how to remove the travel stops: Variable Spring Support Constant Spring Support Read More
What is a spring support?
Added on Fri, Feb 11, 2011
We refer to our spring supports as any assembly which includes a spring (either variable or constant) that can accommodate both a pipe load and a pipe movement. ... Read More
What is meant by "rod take-out" in spring supports?
Added on Tue, Nov 2, 2010
The rod take out (RTO) is the amount of space between the upper attachment point and the lower attachment point of spring hanger assembly. Rod-Take Out Indicated on a Variable Spring Hanger Read More
What are spring supports used for?
Added on Tue, Nov 2, 2010
Spring supports are used to accommodate vertical movement in pipe systems during their thermal deflection cycles. Variable Springs Read More
What is the maximum load variability of a variable spring hanger?
Added on Tue, Nov 2, 2010
Per the MSS standards, the maximum recommended variability for a variable spring hanger is 25%. If required, you can specify a variability less than 25%. Variable Spring and Cro-Moly 3-bolt Clamp Read More
How do I check the load setting of a spring support?
Added on Tue, Nov 2, 2010
To check the load setting, examine the position of the bottom of the load indicator with respect to the scale on the spring's tag. Read from the bottom of the load indicator to determine position. Next, look at the size of the spring located... Read More
How do I know if I need spring hangers?
Added on Thu, Jun 16, 2011
Spring hangers would be utilized whenever one has to accommodate for pipe deflection due to either thermal growth, load changes, or a combination of the two. Constant Spring Hangers Read More
How do I set (load) a spring support?
Added on Tue, Nov 2, 2010
In order to set (load) a spring support, you must ensure that the pipe system is at its cold (installed) state. (All hydro-testing has been completed.) At this point, with variable springs, the lower travel stops should be removed. Adjust the load... Read More
How does a constant spring hanger work?
Added on Wed, Feb 23, 2011
Please see the video below that shows how a constant spring works: How a Constant Spring Functions 78" Long 200 C-Type Constant Spring Assembly Read More
How do you read the load indicator on a spring support?
Added on Tue, Nov 2, 2010
To read the load indicator on a variable spring support, you need to read the measurement aligned with the bottom of the spring load indicator. Read More
Why use a 25% load variation on a variable spring hanger?
Added on Thu, Feb 17, 2011
The 25% load variation on a variable spring hanger is a maximum recommended value. The actual variability for a particular spring support will, in general, be less than the 25% maximum. Read More
How do you attach a spring support to a rod?
Added on Tue, Nov 2, 2010
There are different ways to attach a spring support to a rod. For A-Type constants and variables, you need two separate rods. The top plate of the assembly includes a threaded piece that will connect to an upper rod. A second rod will be connected... Read More
What does travel mean when discussing spring supports?
Added on Tue, Nov 2, 2010
When dealing with variable spring supports, travel refers to the amount of deflection from our installed position to our operating position. When dealing with constant springs, travel refers to the total amount of deflection, which could be... Read More
What is a base-mounted spring?
Added on Tue, Nov 2, 2010
A base-mounted spring is a subset of either variable or constant spring supports where the support is located below the supported member. F-Type Variable Spring Support Read More
What happens if variable spring variability increases?
Added on Fri, Feb 11, 2011
When the variability of a variable spring exceeds the MSS standard of 25%, the designer's first option would be to lower the spring rate so that the difference in load with the same amount of movement would be smaller than that... Read More
How do you calculate the loaded length in a spring?
Added on Wed, Feb 23, 2011
For hanger type variable springs types, a, b, c, d, e, and g, you can utilize the minimum loaded length value (x in the PT&P catalog) and add to that a value equal to your cold load minus the minimum cold load (top red line of the spring... Read More
What does variability mean in pipe supports?
Added on Fri, Feb 11, 2011
Variability applies to variable spring supports and is basically a ratio between the difference in load and the operating load of the spring. The difference in load is a function of the spring rate and travel. Per MSS, the maximum recommended... Read More
How do I verify tension on pipe hangers?
Added on Wed, Feb 23, 2011
In order to verify tension on spring supports, the spring scale can be used as an indicator of the tension (or load) acting through the support rod. Spring Scale Indicated on a Variable Spring Hanger Read More
What is the purpose of support rods when spring supports are used?
Added on Wed, Mar 23, 2011
The support rods are generally used to attach the spring to the stationary support member or structural steel and to transfer the load from the pipe onto the spring. Rods are generally utilized because they can be readily modified to fit existing... Read More
What position should a variable spring be adjusted to before the pipeline is put back into service after a shutdown?
Added on Tue, Feb 1, 2011
The variable spring should be restored to its original installed (cold) position. Variable Spring with White Diamond Indicating Cold Position Read More
How can you tell the spring rate for a hanger?
Added on Wed, Feb 23, 2011
When selecting a new variable spring hanger, refer to the Piping Technology load and travel table which indicates the spring rate associated with a particular size and configuration of variable springs. (see travel table) Variable Spring... Read More
What are travel stops that are used in springs?
Added on Tue, Feb 1, 2011
Travel stops are devices which temporarily lock the moveable parts of a spring hanger in a fixed position, enabling a load to be transferred through the spring hanger to the supporting structure while maintaining the piping at a desired elevation... Read More
What are spring support jacking bolts?
Added on Tue, Feb 1, 2011
A spring support jacking bolt is a variable spring accessory that aids in removing the upper limit travel stops. They are usually used in applications where large installed loads are present. They are located directly above the upper travel stop.... Read More
How do I adjust spring hangers?
Added on Wed, Feb 23, 2011
When referring to adjusting a spring hanger, first you must define whether or not your are talking about a length adjustment or a load adjustment. When modifying the length of a spring support, you would utilize its load column to change its... Read More
Why must you lock a spring hanger during the hydro test?
Added on Thu, Feb 17, 2011
The spring hanger must be locked because in most instances, the hydro test exceeds the installed load and without the stops, the spring coil would deflect when subjected to that higher load. Secondarily, the travel stops act to bypass the coil so... Read More
Why is a variable spring a linear pipe support?
Added on Thu, Feb 17, 2011
Variable springs are linear pipe supports because the spring rates do not change over the working range of a particular type of spring. For example, a 400 pounds per inch spring would remain at 400 pounds per inch given any design travel. ... Read More
What do I do if a constant support is bottomed out?
Added on Tue, Feb 1, 2011
There are two possible situations in which the constant would bottom out. One being the load is larger than anticipated and the other being that the amount of travel exceeds the total travel rating for that particular constant. Under the first... Read More
Why do spring hangers have travel stops?
Added on Thu, Feb 17, 2011
Travel stops are located in spring hangers in order to: 1.) set the initial spring compression at the initial (or cold) load 2.) lock the spring into position whenever hydro testing is performed. Travel Stops Shown on a Variable... Read More
What is a j-rod on a pipe support?
Added on Fri, Feb 11, 2011
When referring to constants, the j dimension refers to the diameter of the rod which transfers our load from the constant to the support component. (i.e. clamp, clevis, etc.) Constant Drawing with J Dimension Shown Read More
How do you install a spring support hanger?
Added on Wed, Feb 23, 2011
Please see our installation and maintenance guide for variable springs: Variable Spring Installation Guide Please see our installation and maintenance guide for constant springs: Constant Spring Installation Guide Variable Spring Hangers... Read More
How do you attach a spring to a rod?
Added on Wed, Feb 23, 2011
For type A, B, C and G variable springs, the rod attaches to the load column of the spring by threading the rod into the existing load column. For D and E type variable springs, the rod extends through the spring housing and then place a washer... Read More
How do you set a piping spring support?
Added on Wed, Mar 23, 2011
Setting the load on a spring support should be done after all hydro-testing has been completed. The first step would be to remove the hydro-test stops. Then, one would utilize the load column to adjust the tension on the spring unit so that its... Read More
How do I adjust the tension on a spring hanger?
Added on Wed, Mar 23, 2011
The tension on a spring hanger is adjusted by turning the load column. Increasing the load seen at the spring would be accomplished by tightening (turning clockwise) the load column at the connecting rod. Conversely, loosening (turning counter... Read More
What are the sizes of hangers?
Added on Fri, Feb 11, 2011
The standard size or "off-the-shelf” components for hangers are available for pipe sizes from 1” up to 36”. The standard load ranges are from 0 lb. up to 90,000 lb. Non-standard sizes can be custom designed and fabricated upon request. ... Read More
What is a cold spring?
Added on Wed, Jun 22, 2011
A cold spring could either refer to the cold load on the spring which references the initial or installed position. Also, that could refer to cold springing which would be using the spring to impart a load which adds to the pipe weight and... Read More
How do I specify final variable spring configuration?
Added on Thu, Jun 16, 2011
There are three general specifications required when delineating variable springs which would be their type, size, and model. The type would be either a PTP-1, 2, 4, 6, or 8 and the size would range from 00 through 220 and the model would be selected... Read More
How does spring rate effect the load variation of the spring in stress analysis?
Added on Thu, Jun 16, 2011
Because the deflection of the pipe system is predicated on its operating conditions, the difference in load between our starting condition and our operating condition is dependent upon the spring rate. A higher spring rate would produce a higher... Read More
What is it called when a spring hanger is above scale?
Added on Wed, Jun 22, 2011
The spring hanger is referred to as above scale when the spring is operating at an under loaded condition meaning that the spring support is too large and has not overcome the initial pre-load built into the spring support. Above Scale Area... Read More
How effective are hanger supports in pipeline failures?
Added on Thu, Jun 16, 2011
In the case of a pipeline failure, all pipe support components, including hangers, are designed with a minimum safety factor of 2.5. While not recommended, one can utilize that pre-designed safety factor to support the pipeline under emergency... Read More
How do you tighten a spring can?
Added on Thu, Jun 16, 2011
To tighten a spring can, one would utilize the integral load column component. When dealing with spring supports with threaded rod connections, tighten the load column at the threaded connection. When dealing with base type spring supports, the load... Read More
How do you check the alignment of the spring in the spring hanger?
Added on Thu, Jun 16, 2011
The alignment (position) of the spring hanger is an indication of the load at the spring location. By viewing the bottom of the indicator tab, shown within the small window on the side of the spring can, one can check the current spring alignment ... Read More
When do you remove the pin from a spring hanger?
Added on Wed, Jun 22, 2011
The pins are removed from a spring hanger after all hydro-testing has been completed, all piping connections have been finalized, and when all starting operations have been completed in the pipe system. See the videos below on how to remove the... Read More
What is the difference between spring hangers and elastomeric hangers?
Added on Thu, Oct 27, 2011
Spring hangers utilize a coil of known dimensions with a linear spring rate whereas elastomeric hangers use pliable solid material to absorb the pipe deflection. Spring Hanger Assemblies Read More
How does the height of the base (F-type) spring have to be specified with downward movement?
Added on Thu, Oct 27, 2011
Steps for height of the base (F-type) spring specified with downward movement: Step 1: For example, using the PTP-1 100-F with downward movement of 1/4 inch, review the loaded length x minimum (9 1/16") and maximum (10 1/16") dimensions. Step 2:... Read More
If a constant spring always allows the pipe to move downwards, then how does upthrust work?
Added on Fri, Nov 25, 2011
Springs allow the pipe to either move up or down. An upthrust is our base-mounted constant wherein the load is above us and the support is from below. Upthrust Constant with Corrosion Resistant Coating Read More
What should we do if we get more or less cold load than what is specified in the spring hanger?
Added on Fri, Nov 25, 2011
If you have too much or too little load, artificially add or detract weight at the spring hanger location by means of a hoist. for example. Once the travel stop is removed you can then adjust to your new or correct cold load. Read More
What should be our horizontal displacement limit while choosing F-Type variable springs?
Added on Thu, Nov 3, 2011
For F-type springs your horizontal displacements should be 1" or less. If they are more than that, use a slide plate. 5′-7 1/2" Inch Tall F-Type Variable Spring Support Assemblies Read More
Can hanger supports accommodate lateral movement of the pipe?
Added on Wed, Nov 23, 2011
Yes. The maximum allowable movement for constant spring hangers per MSS standard is + or - 4 degree swing angle which would be associated with the lateral movement. Constant Spring Hanger Pipe Supports Read More
Is there a standard pre-compression used for spring supports?
Added on Thu, Nov 3, 2011
All springs are pre-compressed to the design load that is specified by the customer prior to manufacture. Therefore, it is possible to custom design the load to your needs. Custom Made Variable Spring Support designed for a Load of 12,000 lb. Read More
What’s the best configuration to support an inclined pipe using the Type F spring?
Added on Wed, Nov 23, 2011
You could incorporate a pipe shoe into your design on the incline, but with the base of the shoe parallel to the F-Type spring. F-Type Variable Spring Supports Read More
Why is there a minimum load for variable spring cans?
Added on Thu, Nov 3, 2011
Because we pre-compress the springs to fit in the can. Variable Spring Supports Read More
How much horizontal movement can the D-Type variable spring take from the pipe?
Added on Thu, Nov 3, 2011
The spring can take up to + or - 4 degrees of movement from the vertical alignment of the position. D-Type Variable Spring Read More
Can a spring pipe support have neoprene rubber coating?
Added on Thu, Nov 10, 2011
Yes, a spring pipe support can have neoprene rubber coating. We offer this type of protective coating on our springs here at PT&P. It is a standard coating on the spring coils and could be added as a supplementary coating on the remainder of the... Read More
Are weep holes provided in the can to help let rain water drain away?
Added on Thu, Nov 10, 2011
Because all variable spring housings utilize a bolted construction, there is no need to provide a drain hole as you might see in a welded construction. This type of fabrication allows water and/or condensation to drain from the bottom of the housing. Read More
How far can a spring go beyond the working range without adding extra thermal load on the piping?
Added on Thu, Oct 27, 2011
The spring will become solid if it is bottoming the can out. This can vary depending on the model of the spring. There is some deflection available beyond the maximum working range load prior to completely compressing the coil. U-Type Constant... Read More
What’s the difference between a neoprene coated coil and a baked epoxy/plastic coated spring coil?
Added on Thu, Nov 10, 2011
Neoprene allows for greater elasticity and also flexibility under cold conditions. Neoprene Coated Spring Read More
What coatings are applied to the spring and spring can to resist corrosion in marine environments?
Added on Thu, Nov 10, 2011
For the springs we neoprene coat our coils. For the spring can housing we can provide either a three coat epoxy finish, neoprene coating over standard galvanized finish, or provide a stainless steel finish. Neoprene Coated Fig. 100 U-Type... Read More
What is meant by the installed height in a Type F variable spring?
Added on Thu, Oct 27, 2011
The installed height for an F-type spring refers to the distance between the base plate and the load flange of an F-type variable spring. The minimum installed heights are specified for each size of variable spring and modifications can be made in... Read More
What is the allowable deviation between preset hot/cold setting and actual pin position?
Added on Thu, Nov 10, 2011
For a constant spring hanger, the allowable deviation is 6%. 200-C Type Constant Springs Read More
What is an example application for a Type F spring?
Added on Thu, Oct 27, 2011
A common example would be to locate the base of the F-Type spring on an existing foundation member and allow the load flange to be in contact with either a dummy leg or trunnion of the piping system above. F-Type Variable Spring with Travel Stops... Read More
How much movement can variable springs take?
Added on Thu, Nov 3, 2011
In general terms, the amount of vertical deflection that can be accommodated by the variable springs is dependent upon the spring rate. In practicality, PTP-1 is used for travels one-quarter inch or less, PTP-2 for travels are one-half inch or... Read More
How often do you recommend maintenance and/or inspection on both your constant & variable springs?
Added on Thu, Oct 27, 2011
We recommend you do a yearly inspection after your springs have been in place 5 years. You can refer to our installation and maintenance guides for more information: Variable Spring Installation Guide Constant Spring Installation Guide ... Read More
What is the expected lifetime of a constant support spring hanger?
Added on Thu, Nov 10, 2011
The lifetime of a constant support spring hanger could last up to 25 years on average. It depends on the environment in which the constant is located. Constant Spring Hangers Read More
What is meant by 6% deviation in terms of constant springs?
Added on Thu, Nov 3, 2011
The 6% deviation refers to the amount of variation from our design load throughout the total travel range of the constant spring which can be allowed and still refer to our load as "constant." U-Type Constant Springs Read More
Can the constant travel or capacity change other than by overheating the spring?
Added on Thu, Nov 3, 2011
Rust can cause the spring to be weaker, wind damage, or chemical damage. Rusted Competitor Constant Spring Read More
How does a spring hanger wear out?
Added on Thu, Nov 3, 2011
Spring hangers can wear out due to time, environment, extreme temperatures, rust, number of cycles, etc. Rusted Competitor Spring Hanger Read More
What type of situations would exist where the installed load is greater than the operating load?
Added on Thu, Nov 3, 2011
This would occur when the spring is specified for upward travel or in other words, upward movement. An example of the load becoming less during operation would be in a steamed line where in our initial stage our pipe would be filled with water and... Read More
During a maintenance activity with a variable spring in the pinned condition, is there a recommended load limit for the locked spring unit?
Added on Thu, Nov 10, 2011
Yes there is a recommended load limit for the variable spring, and the rule of thumb is two times the spring capability. F-Type Variable Spring Support Read More
How can we adjust a large (+/-100,000 lbs) big ton spring?
Added on Thu, Nov 10, 2011
To adjust a big ton spring, you would rotate the nuts that are located on top of the plate pressing the springs and below the load flange. If you need further assistance, you are welcome to contact our field services department at info@pipingtech.com... Read More
When should I use a Type B or C variable spring?
Added on Thu, Nov 10, 2011
The type of variable spring depends on the lateral movement in your piping system and how much welding you are willing to do. The C-type allows for more lateral movement and the B-type requires more welding. Primarily the B- or C-Type are used in... Read More
Is it practical to try to design a variable spring support or constant spring support for travel less than 0.1"?
Added on Thu, Nov 10, 2011
It would not be recommended for a constant spring to be designed for less than 0.1" for travel. Variable springs can accommodate that travel. The difference in load will be a function of the spring rate. F-Type Variable Spring designed for 1/16... Read More
What are the things to be considered while de-blocking the spring hanger?
Added on Fri, Nov 25, 2011
The major point to consider while de-blocking a spring hanger would be to make sure that you are at your true cold condition which means that you can apply the correct installed load that the spring is set to. Variable Spring Set to Cold Load of... Read More
What is the purpose of the spring "lock" on a variable spring can?
Added on Fri, Nov 25, 2011
The purpose of the spring "lock" mechanism is to provide the customer with a pre-loaded support and the hydro-testing of the line must be done with the locks in place to prevent from damaging the support. Spring Lock on a Variable Spring Support ... Read More
Is a roller bearing a part of a constant?
Added on Wed, Nov 23, 2011
It's part of the constant as an added component specified by the customer to provide for movement on pipe lines that require axial and/or lateral movement. Roller Bearings on a Constant Spring Read More |
