Tag: Engineered Spring Support

G-Type Variable Spring Assemblies Designed for an Oil & Gas Refinery in Texas

October 31, 2023

G-Type Variable Spring Assemblies Designed For An Oil &Amp; Gas Refinery In Texas

PT&P designed these G-Type variable spring support assemblies, along with a 24" diameter pipe shoe and hanger, for an oil and gas refinery in one of the largest refineries in Texas that was also the recipient of the American Fuel Manufacturers 2022 Innovation award. Our variables were for the refinery coker unit, which typically converts the residual oil from the vacuum distillation column into low molecular weight hydrocarbon gasses, naphtha, light and heavy gas oils, and petroleum coke.

Each variable spring support assembly was designed with a center-to-center of 36" and an elevation difference of up to 72". The spring supports consist of a G-type variable spring, all threaded rods, clevis, lifting lugs, welding lugs, and clevis pins. They are designed with an operating load range from 1,700 lb. to 10,500 lb. and a movement range of .02" to .19" up or down. Standard load and travel testing was completed before shipment.

The refinery was originally constructed in the 1930s. PT&P and our subsidiaries have deep experience with maintenance and replacement work at existing facilities to keep them running and producing for our clients. Our field service teams are available to do an audit, inspection, or replacements of variable spring cans based on your needs.

PT&P REF. ORIGINAL POST 08092016

U-Type Constants Designed with Slide Plates for a Polypropylene Plant in Texas

July 4, 2023

147164A1

PT&P designed and fabricated a U-Type constant spring support , with PTFE and a 25% glass-filled side plate for a Polypropylene Plant in Texas. The constant is fabricated from carbon steel and hot-dipped galvanized for extra protection against corrosion. The vertical movement is 1.5" total upward travel and is capable of supporting a load of 10,350 lbs. throughout its range of movement. The constant underwent standard load testing prior to shipment.

Along with chemical plants, constant spring supports are utilized in refineries, power plants, and heat recovery steam generators (HRSG). The design of the constant spring support replaced a system of pipe support called a "counterweight" design still used in some facilities today. The counter-weight system utilized pipe clamps or lugs (attached or welded to the pipe), cables, pulleys, and a set of weights. Just like the old-fashioned brass weighing scales, weights were added to one end of the pulley system until an equilibrium was reached. The counterweight design needed a large amount of space with which to operate. Constant spring hangers replaced this system because they require much less space in order to function (similar to some designs we stand on to weigh ourselves). No matter the application, our team of experienced engineers and designers can help to resolve your pipe support needs. Please contact us via our 24×7 emergency service or send an email to info@pipingtech.com.

PT&P REF. ORIGINAL POST 08232016

What does the red, white, and blue markings mean on a constant spring support?

November 23, 2021

Red, White and Blue Marks:

All constants are shipped with at least 3 color-coded rivets (red, white and blue).
Red: operating (HOT) position
White: installation (COLD) position
Blue: over travel (MAX AVAILABLE) position

Below are sketches of one direction vertical travel:

Installation Maintenance Rivets One Direction

 

 

Below is a sketch of dual direction vertical travel:

 

Rivets Two Directions

Variable Supports Fabricated in 48 hours for an Emergency Plant Shutdown

April 13, 2021

Variable Spring Supports Fabricated In Less Than 48 Hours For An Emergency Plant Shutdown Overseas In The Asia-Pacific Region

PT&P received a rush order this past week for variable spring supports at 4:41 pm, quite late into the workday; however, this is business as usual, our manufacturing facility in Houston, TX operates 24/7 to support our customers.

In this case, the customer facility, an olefins plant was incurring a significant loss and needed to replace the springs to resume operations as quickly as possible. The seven (7) variable springs were designed, fabricated, and shipped within 2 days. The F-type variable spring support is designed to support piping from below, directly from the foundation, concrete column, or supporting structural pipe rack steel. Adjustment is made by inserting a bar into holes in the load column and turning the load column as a jackscrew. The base plate is bolted to the case and has four holes for fastening.

As global leaders in variable spring manufacturing, we used our adaptive manufacturing processes in which the PT&P pre-fabricated component parts that make up these variables are easily assembled when orders are placed. These variables were fabricated from carbon steel and hot-dipped galvanized for corrosion protection. They are designed to support loads ranging from 713 lb. to 1668 lb. and movements of 0.148” to 0.133”. Load and travel tests, along with Q.C. inspections were performed before shipment. Variable springs are used in mills, refineries, chemical, plastics, polymer, solar, power, biochar, renewables, carbon black, LNG boilers, food, packaging, and wastewater treatment plants to support piping as it goes through its’ range of movement.

Variable Rush Job 183959B Variable Rush Job 183959C

C-Type Variable Spring Supports Designed for a Power Plant

August 24, 2015

C-Type Variable Spring Supports Designed For A Power Plant

PT&P designed C-Type variable spring support assemblies for a power plant in Louisiana. They are designed for operating loads ranging from 1,319 to 2,800 lb. with an upwards travel ranging from 0.11″ to 0.34″. The variables were fabricated from carbon steel with a hot-dipped galvanized finish and standard load and travel testing was completed prior to shipment

What is a constant spring support?

November 2, 2011

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 there is no difference in load and the supported load will remain uniform throughout the deflection cycle.

U-Type Constant Springs Custom Designed For Large Travel For An Oil Refinery
U-Type Constant Springs

What happens if variable spring variability increases?

February 11, 2011

When the variabilityof a variable springexceeds the MSS standard of 25%, the designer's first option would be to lowerthe spring rate so that the difference in load with the same amount of movementwould be smaller than that associated with the higher spring rate. The designerwould continue this exercise until a variability factor of less than 25% isachieved.

What does variability mean in pipe supports?

Variability applies to variable spring supports and is basically a ratiobetween the difference in load and the operating load of the spring. Thedifference in load is a function of the spring rate and travel. Per MSS, themaximum recommended variability would be 25%. However, critical systems such asmain steam supports may require variability factors less than 25%.

What is a spring support?

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 pipemovement.

Foto 018U-Type Constant Springs Custom Designed For Large Travel For An Oil Refinery

Variable Springs Constant Springs

What position should a variable spring be adjusted to before the pipeline is put back into service after a shutdown?

February 1, 2011

Thevariable spring should be restored to its original installed (cold) position.

Variable Spring With White Diamond Indicating Cold Position
Variable Spring with White Diamond Indicating Cold Position


What are spring support jacking bolts?

A spring support jacking bolt is a variable spring accessory that aids inremoving the upper limit travel stops. They are usually used in applicationswhere large installed loads are present. They are located directly above theupper travel stop. By tightening the jacking bolt, the installed load can bemore easily transferred to the spring load column.

 
F-Type Variable With Jacking Bolts
F-Type Variable with Jacking Bolts

Big Ton Spring Support Designed for a Maximum Load of 93,000 lb. for a Chemical Plant in Baton Rouge, Louisiana

November 29, 2010

Big Ton Spring Support Designed For A Maximum Load Of 93,000 Lb. For A Chemical Plant In Baton Rouge, Louisiana

This big ton spring support measures 40″ length x 36″ width x 43″ height. It is composed of a carbon steel frame, neoprene coated spring steel coils, and has a hot-dipped galvanize finish. It also includes a guided load table to ensure stability when supporting the maximum load of 93,000 lb. Standard load and travel tests were performed prior to shipping.

Do you see a need for big tons springs in your piping system? Get pricing today!
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How do I select a pipe hanger?

November 2, 2010

The design parameters that must be considered when selecting a pipe hanger would include operating temperature, operating load, movement, pipe material, available space, and allowable initial load requirements. Once these are known, then you can select an appropriate type of pipe hanger which could be any of the following types including rigid hangers, variable spring hangers, or constant spring hangers.

Variable Spring Hanger Installed In The Field
Variable Spring Hanger Installed in the Field

How do I set (load) a spring support?

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 at the load column of the spring so that a load slightly above the cold load is reached. The remaining travel stops can now be removed. Note: Excessive force should not be required to remove the travel stops at this time.

See Video on How to Remove Travel Stops from a Variable.

What are the sizes of spring supports?

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 Springs For A Local Chemical Plant

F-Type Variable Spring Supports

24,500 Lb. Load Ptp- 8 Type C Variable Spring Assemblies
PTP-8 Type C Variable Spring Assemblies

123 100 C Constant Spring Supports With Double Lug Suspension And Chained Travel Stops For An Oil Refinery In Canada 1

Figure 100 C-Type Constant Springs

Constant Springs 5
PTP 100-C Size 84 Constant

How do you attach a spring support to a rod?

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 to the bottom by the spring’s threaded load column.
For B-Type and C-Type constants and variables, you need one rod to attach to the spring assembly’s threaded load column.
For D-Type and E-Type variables, a single rod runs from the bottom through the top of the spring and hex nuts are used to secure the rod in place.
For D-Type and E-Type constants, a single rod is attached using a turnbuckle.

Variable Spring Support Types
Variable Spring Support Types

Variable Spring and Rod Assemblies

Constant Spring Support

How much weight can a spring support?

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 Spring Designed For A 35, 144 Lb. Load
Constant Spring Designed for a 35, 144 lb. Load

How do I remove a spring support?

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 have adequate support, you can release the load from the spring. Finally, remove the spring support from the piping system.

Variable Spring Support With Travel Stops In Place
Variable Spring Support with Travel Stops in Place

How do you read the load indicator on a spring support?

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.

Load Indicator On A Variable Spring

How do I check the load setting of a spring support?

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 on the tag. Then, refer to the appropriate load and travel table (Constant Load & Travel Table or Variable Load and Travel Table) to determine the respective spring rate and the “0” load (minimum working range load). Multiply the spring rate by the position value and add that to the “0” load value.

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