An Overview of the Structure of Insulated Pipe Supports
When people ask me what I do for a living my response is, “Go inside any commercial building or garage and look up.” It may not be glamorous, but it is extremely important. The primary reason for insulated pipe supports is to support the weight of the pipe. The secondary reason is to provide continuous insulation throughout the system. In addition, many pipes expand and contract as the temperature becomes hotter or colder. Without an insulated pipe support, this expansion and contraction may stress the pipe and may cause damage. Insulating a complete system is key to maintaining insulation’s benefits. The insulated pipe support is essential to the proper functioning of the entire hanger assembly.
The most important thing that we have learned from listening to our customers for more than 26 years is that when it comes to insulated pipe supports, a seamless and integrated system design is vital to the success of the installation, function, and long-term viability of the product. This creates a functional support and also adds aesthetic value to the overall installation.
There are 3 distinct market segments within the contracting community for utilizing insulated pipe supports. They each have unique requirements and needs specific to the installation.
The mechanical trade installs the hanger assembly. This includes steel, cast iron, and stainless steel, copper, and plastic pipes.
The plumbing trade installs 3 types of pipe, with supports required for all 3. This includes copper, cast iron, and thermoplastic.
Per ASTM C-585, the dimensional standard for pre-formed thermal insulation for pipes and tubing, insulated pipe supports must match the outside diameter of the pipe and installation. This is important because each support needs to fit the pipe without being too loose or tight. Without a proper fit, the pipe has unnecessary stress that could cause it to crack or break.
In addition to controlling temperature and saving energy, 2 of the great advantages of insulated pipe supports in this industry are ease and time savings. Insulated pipe supports installed on a clevis hanger are incredibly simple to install. The contractor doesn’t have to work directly with the pipe hanger and the installation process only requires making a butt joint between the pipe insulation system and the insulated support.
Important Industry Considerations
When utilizing insulated pipe supports, there are many important considerations to weigh.
Flame/Smoke Rating per ASTM E84—This test measures both a flame spread index and a smoke developed index of the flat material being tested. Various factors, including location within a building, determine the flame/smoke indices required. In plenums, pipe insulation must meet a flame/smoke index no greater than 25/50.
Vapor Retarders—Vapor retarders greatly reduce the flow of moisture from the ambient environment into the insulation system. This is important to prevent mold and pipe corrosion, to reduce the likelihood of surface condensation on the insulation system, and to improve the longevity of the insulation system. The standard is a maximum of a 0.02 perm rating for the vapor retarder.
Insulation within the Support Must Carry the Weight of the Pipe—Many factors must be considered related to supporting the weight of the pipe. These include the span between supports, shield length, safety factors, pipe size and schedule, pipe contents, and more. Remember that you are not just supporting the pipes, but the fluid as well. Taking shortcuts to save time or money by placing supports further apart without using commensurately higher strength insulation at the supports can cause deterioration and breakage of the insulation at the support locations.
Seismic Conditions—Seismic conditions must be addressed. You must make sure the hanger assembly has the ability to maintain its integrity in an earthquake.
Critical Manufacturer Requirements
Not all insulated pipe supports are equal. Here are some important facts to consider.
Fire Rating—Make sure the product you are using is tested by the manufacturer per ASTM E84. The product must be tested for fire rating.
We often run across products that are foam based or use wood blocks. Keep in mind that foam-based products have widely varying flame/smoke ratings and wood blocks are not a fire-rated product. Even worse, wood blocks provide a food source for mold.
Vapor Retarder—Another critical consideration is the insulation vapor retarder. Insulation vapor retarders are generally stressed on systems that run below ambient temperature. A sealed vapor retarder is the first line of defense against water vapor intrusion and corrosion under the insulation. These would be most prevalent on systems operating between 100˚F and 300˚F. The best solution is a full sealed vapor retarder through the hanger. It should extend past the protection shield so that it seals the entire insulation system.
Different types of effective vapor barriers include:
- Metalized polyester all service jacket (ASJ);
- Zero-perm products; and
- Polyvinylidene chloride (PVDC).
You will sometimes see PVC jacketing and galvanized metal offered as a vapor barrier. Keep in mind that these products are not vapor retarders and should not be used for this purpose.
Common Products Used in the Pipe Support Industry
One of the advantages of using calcium silicate is that this product is dense and provides a great deal of structural support with a compressive strength of 100 PSI. The dense nature of this product means that the pipe support doesn’t have to be as long because it provides structural strength. We recommend the use of this product in the majority of our hot applications and cold applications with a vapor barrier.
Polyisocyanurate is a good option for cold and cryogenic applications. This product is closed cell, which is beneficial because it limits the moisture intrusion. Some grades of PIR have 25/50 flame/smoke ratings and most grades meet a flame/smoke rating of Class A/Class 1. Also keep in mind that in an installation, you must match the density of the foam used in the supports to the forces exerted at these locations. Larger spans between supports usually will require greater compressive strength from the insulation so this must be considered. The larger the pipe span, the more you must increase the density to support the weight of the pipe. Density ranges from 2 ½ to over 30 pounds.
This product is a good option for cold applications such as refrigeration and chilled water. Up to 3 inches thick phenolic, which is the most that would be needed in these applications, has a flame/smoke rating of ≤25/50, so it can be used as pipe insulation in commercial building areas.
While I do not often use it, cellular glass is a closed-cell non-combustible foam of glass. It is used in both above- and below-ambient systems as insulated pipe supports for small- to medium-diameter piping.
Pipe Support Guidance
There are multiple governing bodies within this industry that we rely on for building or pipe support standards.
ASHRAE—American Society of Heating, Refrigeration, and Air Conditioning Engineers
ASHRAE publishes standards and guidelines that relate to HVAC systems and issues. These standards are part of many building codes.
ANSI—American National Standards Institute
ANSI is a nonprofit organization that oversees many of the standards that we use. ANSI does not develop standards but works with those developing standards to ensure the procedures used are solid. ANSI accreditation indicates that the procedures used meet requirements for openness, balance, consensus, and due process.
ASTM—American Society for Testing and Materials
ASTM develops over 12,000 voluntary consensus standards, many of which apply to the pipe-support industry. These are referenced frequently and many become mandatory by corporation and government contracts.
AWS—American Welding Society
The American Welding Society maintains code and certification procedures, which help to provide industry standards for the welding and joining of metal, plastics, and other materials.
MSS—Manufacturers Standardization Society
The MSS of the valve and fittings industry references all of the pipe support standards when outlining procedures for manufacturing components and systems for the field.
These standards have been a driving force in our industry for nearly 60 years since they were first set in 1958. Here are some key components of the standards that apply to the insulated pipe support industry.
- A Type 40 shield is defined by the length and gauge on the outside of the insulation.
- The minimum requirement is 18 gauge and 12” long.
In 1966, the MSS standards were updated to allow for an alternative type 40 shield. They require:
- High compressive strength insert (6” and larger seems to be the standard in most applications);
- Vapor barrier; and
- Appropriate shield.
Insulated pipe supports in the industrial market are unique and special in many ways. The majority of applications are highly customized and engineered. We rarely see “off the shelf” products for this market. Some of the considerations for the industrial market include:
- Large pipes. Some pipe hangers are so large you can walk through them!
- Higher loads. They need to be created to withstand much higher loads than any off-the-shelf product.
- More movement. Industrial applications tend to see more movement in the pipe due to large volume and greater differences in temperatures.
- Low Temperatures. In some cold applications, products need to be designed to withstand temperatures as low as -320°F and sometimes even colder.
- High Temperatures. Products need to be designed to withstand temperatures as high as 1500°F in some cases.
Higher Temperatures in the Industrial Market
In the higher-temperature industrial market, denser materials are made from high temperature, calcium silicate (Type II, Grade 5 and 6) board material. Boards start at a compressive strength of 450 PSI and go as high as 3050 PSI. Pipe loads determine the length of insulated pipe support. The larger the pipe, the longer the support must be in order to properly hold the weight. The MSS sets the standards for minimal allowable loads between hangers.
Cryogenic Applications in the Industrial Market
In applications that produce incredibly low temperatures, another unique set of requirements is presented. The density of poured urethane foam starts at 2 pounds per cubic foot (PCF) and goes to 30 PCF. Multilayer and low permeance vapor retarders are required in order to keep ice from forming and to minimize moisture intrusion into the insulation system.
For hot and cold industrial applications, insulation thickness varies widely depending on many factors. It can be as little as ½ inch to nearly unlimited thickness depending on the project.
Advantages of Insulated Pipe Supports
For a contractor, one of the biggest advantages of utilizing an insulated pipe support is cost savings. Whether the application is for mechanical or plumbing, the presence of the insulated pipe supports reduces the amount of labor required by the contractor. Depending on the size of the project, this can result in large cost savings or the ability to lower your bid and win projects.
As a building or facility owner, insulated pipe supports help to conserve energy. They will continuously help to reduce heating and cooling costs in the buildings where they are installed. A properly insulated system means equipment doesn’t have to work as hard, therefore reducing maintenance costs. This also helps avoid down time and extends the life of the equipment and the insulation system.
Partner with Experts
For a successful outcome, make sure to partner with companies that have deep expertise in this industry. Know the markets you serve and make sure to be knowledgeable about the relevant standards that apply.
This article was published in the August 2017 issue of Insulation Outlook magazine. Copyright © 2017 National Insulation Association. All rights reserved. The contents of this website and Insulation Outlook magazine may not be reproduced in any means, in whole or in part, without the prior written permission of the publisher and NIA. Any unauthorized duplication is strictly prohibited and would violate NIA’s copyright and may violate other copyright agreements that NIA has with authors and partners. Contact firstname.lastname@example.org to reprint or reproduce this content.