About Fiberglass Pipe Insulation
Fiberglass insulation is most commonly used for steam pipes since their temperature could melt typical foam pipe insulation. However, it also has a widespread use in plumbing, heating and other applications in places where a fire-resistant insulation is desired or required by code.
Pipe insulation sizing - the basics: OD - Outside Diameter either of the pipe (Pipe OD Size), regardless of type, or Insulation (Insulation OD Size). Some pipes of different nominal sizes and types have an OD which either matches or is very close, making one insulation size suitable for both. Insulation OD Size is indicated mostly for selecting the proper size hanger (clevis or swivel ring type) and the insulation shield (a steel cradle used for supporting the insulated pipe which prevents damage to the insulation from the weight of the pipe).
ID - in this category, it is the Inside Diameter of the insulation, or the size of hole/opening in the insulation. It can be used interchangeably with pipe OD for proper sizing.
Nominal Size - is a familiar and commonly accepted means to identify pipe size (do not confuse with OD or ID). Examples are 1/2" copper pipe, 3/4" black pipe, 2" PVC pipe, etc. All these pipes have an OD and ID which do not match their Nominal size. Across the US, nominal sizes are universal and are used for easy identification of nearly all pipe sizes.
IPS - Iron Pipe Size, is a nominal size, commonly referring to rigid metal pipes (black, brass, galvanized, stainless steel, etc.) and PVC/ABS pipe (schedule 40 & 80).
CTS - Copper Tube Size, is a nominal size, commonly used for copper, PEX and CPVC plumbing pipes. A familiar 1/2" copper pipe is 1/2" CTS and so is 1/2" PEX pipe and 1/2" CPVC pipe. All CTS pipes have the same OD (which is 1/8" larger than CTS), so a 3/4" PEX/Copper/CPVC pipe is 7/8" OD.
How to select proper size fiberglass pipe insulation:
1. Match the pipe size to insulation ID - the easiest way is to use our category filter to match your specific pipe type & size/diameter (whether OD or nominal) to the insulation inside diameter/opening.
2. Select insulation wall thickness - the thicker the walls, the higher the R-value of the insulation, but so is the price. Higher R-values require larger initial investment, but offer bigger savings down the line. Also, consider that some localities have codes which require insulation to be of a minimum thickness (usually 1").
3. Calculate length needed - all fiberglass pipe insulation we sell is 3ft long, so simply divide total pipe length by 3 and round to the next highest number to get the number of insulation pieces needed. We also recommend a factoring in a minimum of 5-10% spare.
Frequently Asked Questions
Q: Is fiberglass pipe insulation moisture-resistant?
A: The short answer is no. In moist environments, fiberglass may absorb water and loose its' insulating properties. The outer jacket on the insulation is vapor resistant, meaning it will protect the insulation from occasional exposure to water vapor and possibly even mist or droplets.
Q: What's the max rated temperature?
A: 850°F
Q: What does ASJ mean in fiberglass pipe insulation?
A: ASJ stands for All-Service Jacket, indicating a standard vapor-resistant jacket (laminated aluminum foil with fiberglass yarn reinforcement and white Kraft paper outer layer).
Q: What does SSL mean in fiberglass pipe insulation?
A: SSL stands for Self-Sealing Lap, indicating that insulation comes with an adhesive-backed strip which closes the seam and prevents accidental or unwanted insulation removal.
Q: What is the difference between Micro-Lok standard and Micro-Lok HP (High-Performance) Insulation?
A: HP insulation is a better quality version of the standard one, with more consistent fibers and jacket which is better fitted to the fiberglass core.
