SECTION 21 0716 – FIRE SUPPRESSION EQUIPMENT INSULATION
This section includes insulation materials for equipment normally found in water-based fire suppression systems.
Thermal insulation provides numerous and varied uses in the commercial application of fire suppression equipment. Simply stated, thermal insulation decreases heat flow between two surfaces. Insulation can reduce heat loss for heat traced equipment or the application may be unrelated to heat loss with the net result that heat transfer is reduced. Examples of this are for personnel protection where a sufficient amount of insulation is provided to keep the surface below a given temperature. In both cases heat transfer is reduced to maintain the surface temperature at a predetermine temperature.
Correctly designing and specifying an insulation system is more complex than simply selecting a certain material. An insulation system is an array of insulation materials to be used in combination with sealants, adhesives, mastics, membranes, coatings, barriers and/or other accessories that will decrease heat flow. An insulation system that is poorly designed is subject to damage and deterioration. Deterioration will compromise the performance characteristics of the material and in certain cases, the application or process for which the insulation system was designed. Different types of insulation materials are available with each type having its own set of performance characteristics and properties. Each insulation material with associated accessories requires a specific application procedure. The key word to remember is “system” which consists of insulation materials, application, and finish. When specifying an insulation system, the following considerations need to be addressed prior to design:
- Fluids being insulated.
- The purpose of insulation.
- The type of insulation material.
- Finish required.
- Temperature limits.
- Where is the project located and the environmental conditions?
- What are the temperature limits?
Fluids being insulated: Insulation materials prone to absorption of fluids such as hot oils/heat transfer fluids that could be found in the coolant piping for remote radiator of indoor, engine-driven fire pump and cause that fluid’s flash point to be reduced shouldn’t be used in such service. Non-absorbent type insulation materials should be used in such service.
The purpose of insulation: Is it necessary for personnel protection, noise control, fire protection, freeze protection, etc. or to reduce heat gain, limit heat loss, or limit surface condensation? The intended purpose may require different materials, finishes, thicknesses, and amount of insulation.
Insulation only provides a way to control, limit, conserve, or minimize the rate of heat transfer. It will not maintain a constant temperature within a system or stop heat flow. It simply reduces the rate of heat flow which makes it a vital component in the heat tracing of equipment and fire-water holding tanks exposed to freezing conditions.
The amount of insulation required for personnel protection is dictated by the amount needed to reduce the surface temperature to a level that prevents a person from getting burned. In general, limiting the surface temperature to 140 degrees F (60 degrees C) will be satisfactory. The Reader is referred to “ASTM C1055 – Standard Guide for Heated System Surfaces Conditions That Produce Contact Burn Injuries” for recommendations in determining acceptable temperature limits. As a general rule, insulation for personnel protection should be installed in areas accessible to maintenance personnel during normal building maintenance and operation. Coverage should extend up to 3 ft (1m) in any direction from a platform or work area and vertically to a height of 7 ft (2 m). The ends of the insulation should always be flashed to prevent moisture intrusion behind the insulation to prevent surface corrosion and deterioration of the insulation. It is noteworthy to ensure that the temperature limits of the mastic and sealant are not exceeded by the design temperature of the surface receiving personnel protection. In installations that have high solar loads, highly reflective metal jacketing reflects much of the radiant heat which could result in surfaces too hot to the touch. Textured, painted, or dull surfaces exhibit a tendency to absorb more radiant heat which creates a surface temperature cooler to the touch. Metal jacketing which is gray coated may result in a reduction of insulation thickness for personnel protection by as much as 2 inches (5 cm). In general, the closer the emittance of the material is to 1, the cooler the surface temperature will become. Wind conditions also need to be taken into account when selecting insulation for personnel protection. For instance, in open areas with prevailing winds, the amount of insulation required would be less than the amount required in a wind sheltered, enclosed area.
Freeze protection can only be maintained by sustained fluid flow through piping with insulation or by some form of additional heat input such as heat tracing between the surface of fluid containment and the insulated covering. Insulation alone cannot maintain a temperature above freezing. All it will do is delay the time required for a fluid to reach its freezing temperature. Freeze protection can also be applied to the prevention of product solidification of diesel fuel in the application of fire pumps powered with diesel engine drives. Diesel fuel gelling happens when the paraffin usually present in diesel starts to solidify when the temperature falls. At 32 degrees F (0 degrees C), the wax in liquid form will crystallize and leave the fuel tank clouded. At 10-15 degrees F (minus 12 to minus 9 degrees C), it will finally start to gel and clog the tank and fuel filters and no longer flow through the fuel lines to the fire pump engine. NFPA 20: STANDARD FOR THE INSTALLATION OF STATIONARY PUMPS FOR FIRE PROTECTION (2013 edition) states the following in regards to freeze protection:
- 4.12.1: “The fire pump, driver, controller, water supply, and power supply shall be protected against possible interruption of service through damage caused by explosion, fire, flood, earthquake, rodents, insects, windstorms, freezing, etc.”
- 188.8.131.52.1: “Suction pipe shall be installed below the frost line or in frost-proof casings.”
- Annex A.10.2.1: “If the controller must be located outside the pump room, a glazed opening should be provided in the pump room wall for observation of the motor and pump during starting. The pressure control pipe should be protected against freezing and mechanical injury.
Physical and mechanical conditions need to be taken into consideration in the design of an insulation system. Rigid insulation is deformation resistant to foot traffic. Areas that experience repetitive personnel use/access or loads require a more hardy insulation system than inaccessible areas. Piping used as walkways/ladders and riggings hung from pipes and horizontal surfaces that are subjected vibration-loads are examples where rigid insulation needs to be used. Compressible insulation should be used for filling voids and closing gaps in rigid insulation to allow expansion, contraction, or movement of rigid insulation. Protection from mechanical abuse is unique to each project. Insulated items that are located in high traffic areas need to have a structure (e.g. platform) to prevent being stepped on by maintenance personnel.
Insulation materials are many and varied for fire suppression equipment. Some of the most common insulations for commercial applications are:
- Fibrous Materials (Mineral Wool and Fibrous Glass; board, blanket, pipe, and block)
- Cellular Glass
- Flexible Elastomeric
- Calcium Silicate
- Polyolefin (Polyethylene)
A comparison of ASTM values for these insulation types and other insulation materials can be found in the “Insulation Material Specification Guide” available for download from the National Insulation Association website at www.insulation.org. Articles and technical information include:
- Guide to Insulation Product Specifications
- Insulation Materials Specification Guide
- Insulation Thicknesses for Economics & Burn Protection
- Manufacturers’ Technical Literature
- National Commercial & Industrial Standards Manual
- Technical Articles
It is noteworthy to remember when analyzing material properties, that most of the time ASTM test methods are performed under laboratory conditions that may not represent field conditions that are dependent on the environment, operating conditions, and temperatures.
Fibrous materials (mineral wool and fibrous glass) are two different types of insulation that possess similarities in their physical properties and applications. The use of these materials is not recommended where physical or mechanical abuse may be prevalent. Fibrous insulations are composed of small diameter fibers that finely divide the air space. The fibers may be inorganic or organic and are typically held together by a binder. There are some exceptions to this rule. Typical inorganic fibers include rock wool, glass, alumina silica, and slag wool. Over the years some confusion has developed over the names used for these materials. Fiberglass products are sometimes called “fibrous glass” or “glass wool” and mineral wool products are sometimes referred to as “rock wool” or “slag wool”. They are all covered by the same ASTM “Mineral Fiber” specifications, and sometimes by the same type and grade. Specifiers are cautioned to call out both the specific material and the ASTM type and Grade when specifying these products. The insulation types are classified primarily by “maximum use temperatures”.
- Mineral fiber pipe insulation is addressed in ASTM C547 which contains five (5) types, from 850 degrees F (454 degrees C) up to 1400 degrees F (760 degrees C).
- Mineral fiber block and board is addressed in ASTM C612 which contains seven (7) types, from 450 degrees F (232 degrees C) up to 1800 degrees F (982 degrees C).
Cellular glass insulation is a rigid, dense, material typically used in applications from 100 degrees (38 degrees C) to 400 degrees (204 degrees C) for Type II (pipe). It is comprised of a rigid, inorganic, non-combustible, impermeable, and chemically resistant form of glass which is available un-faced or faced (un-jacketed or jacketed). Because of the wide temperature range, different fabrication techniques are sometimes used at various temperature ranges. Typically, fabrication of cellular glass insulation involves gluing multiple blocks together to form a “billet” which is then used to produce pipe insulation or special shapes. Depending on the intended use and design operating temperature the adhesives or glue may vary. Hot melt adhesives such as ASTM D312, Type III asphalt, are typically used in below-ambient applications. An inorganic product such as gypsum cement is typically used as the fabricating adhesive on above-ambient systems or where organic adhesives could present a problem as in the handling of liquid oxygen. The specification application may require other types of adhesives. When specifying cellular glass insulation, always remember to include system operating conditions to ensure proper fabrication. ASTM C552, which defines this insulation type, contains the requirements for flexural and compressive strength, water-vapor permeability, water absorption, density, surface burning characteristics, and combustibility. The closed cell structure of this insulation makes it suitable for low temperature applications and for use on equipment where fluid absorption into the insulation could cause problems.
Flexible elastomeric insulation is defined in ASTM C534 as Type I or Type II. Type I consists of preformed tubes whereas Type II is made up of sheets. All termination points and seams are required to be sealed with contact adhesive as recommended by the manufacturer. A weather-proof jacket or coating as recommended by the manufacturer must be applied for protection against ozone and UV in outdoor applications. The following three (3) grades are generally available:
- Grade 1 for typical commercial systems. Temperature Limits: Minus 297 degrees F (minus 183 degrees C) to 220 degrees F (104 degrees C).
- Grade 2 for high temperature uses. Temperature Limits: Minus 297 degrees F (minus 183 degrees C) to 350 degrees F (177 degrees C).
- Grade 3 for stainless steel applications above 125 degrees F (52 degrees C). Temperature Limits: Minus 297 degrees F (minus 183 degrees C) to 250 degrees F (121 degrees C).
Calcium silicate insulation is made up of a rigid, dense material which is used in above-ambient applications to 1200 degrees F (649 degrees C) for Type I and Type IA, and 1700 degrees (927 degrees C) for Type II. ASTM C533 defines this insulation which has been the standard in the industry for applications involving high temperatures. Not only does it possess good compressive strength, it is also noncombustible. It can be supplied as hollow cylinder shapes split in half as curved segments or in straight lengths of 36 inches (91 cm) in sizes compatible with most standard pipe sizes. Thicknesses from 1 inch (2.5 cm) to 3 inch (7.6 cm) are generally available with thicker materials supplied as nested sections. Block type insulation is supplied as flat sections in lengths of 36 inches (91 cm), widths of 6 inches (15 cm), 12 inches (30 cm), and 18 inches (46 cm) and thickness from 1 inch (2.5 cm) to 4 inches (10 cm). Grooved block is available for applications involving fitting to curved surfaces with large diameters. Fitting and/or valve insulation which are special shapes can be fabricated from standard sections. Typically, calcium silicate is finished with a fabric or metal jacket for weather protection and appearance. The maximum thermal conductivity at a mean temperature of 100 degrees F (38 degrees C) is specified to be 0.41 Btu-in/ (hr-sq ft-deg F) for Type 1 and 0.50 Btu-in/ (hr-sq ft-deg F) for Type 1A and 2. The standard also contains requirements for flexural (blending) strength, compressive strength, linear shrinkage, surface-burning characteristics, and maximum content as shipped. Typical applications include piping and equipment operating at temperatures above 250 degrees F (121 degrees C).
Polyisocyanurate rigid foam insulation is used in applications ranging from minus 297 degrees F (minus 183 degrees C) to 300 degrees F (149 degrees C). The insulation is 90 percent closed cell possessing excellent thermal properties. In general, it is manufactured in a range of compressive strengths and densities into large rectangular buns resulting in sizes 4 ft (1.2 m) wide by 3-24 ft (0.9 – 7 m) long by 1-2 ft (30 – 60 cm) in height. The buns are then fabricated into various shapes including including flat boards and preformed pipe half-shells 3-4 ft (.9 – 1.2 m) long designed to fit NPS pipe and tubing. Additionally, convoluted and complex shapes can also be fabricated to fit around fittings, valves, and other equipment. ASTM C591 contains requirements for thermal conductivity, density, water absorption, water vapor permeability, compressive resistance, closed cell content, hot-surface performance, and dimensional stability. It lists two Grades and six Types. The Types identify various densities with the most commonly used densities falling into the 2-2.5 lb/cu ft (32 – 40 kg/cu m) range (types IV and II). The two Grades, 1 and 2, correspond to two ranges of temperature applications. Grade 1 is designed for a temperature range application of minus 70 degrees F (minus 57 degrees C) to 300 degrees F (149 degrees C) while Grade 2 corresponds to a temperature range of minus 297 degrees F (minus 183 degrees C) to 300 degrees F (149 degrees C). Typical applications include equipment, pipe, and tanks operating at temperatures below ambient.
Polystyrene insulation is a rigid, cellular foam insulation. Common classifications are extruded polystyrene foam (XPS) or expanded polystyrene foam (EPS). XPS is a closed cell material manufactured in sections typically 20 inches (508 mm) wide by 9 feet (2.74 m) long by 10 inches (254 mm) high. Prior to actual installation, the sections are fabricated into various shapes including preformed pipe half-shells 3 feet long designed to fit NPS pipe and tubing. Complex shapes can also be fabricated to fit valves, fittings, and other equipment. ASTM material specification ASTM C578 covers several types of polystyrene insulation, but Type XIII is usually specified for fire suppression equipment and covers service temperatures from minus 297 degrees F (minus 183 degrees C) to 165 degrees F (74 degrees C). The standard contains requirements for thermal conductivity, compressive resistance, flexural strength, water permeability, water absorption, and dimensional stability. For comparison purposes, the thermal conductivity of the Type XIII XPS is a maximum of 0.259 K (0.037 Ksi) at 75 degrees F (24 degrees C). Key applications for XPS are installations on equipment, piping, and tanks exposed to freezing temperatures.
Phenolic insulation consists of a rigid foam insulation having a closed-cell structure. It is manufactured in sections typically 4 ft wide by 3-12 ft long by 1-2 ft high at a density of 2 lbs per cubic ft. Before installation, the sections are fabricated into various shapes which include flat boards and preformed half shells 3 ft long that are suited to fit over NPS tubing and pipe. Complex shapes can also be fabricated to fit around elbows, fittings, and other equipment. ASTM C1126, Type III, Grade 1 specifies this type of insulation at service temperatures from minus 290 degrees F (143 degrees C) to 257 degrees F (62 degrees C). The standard defines requirements for compressive resistance, density, water absorption, thermal conductivity, water vapor permeability, and dimensional stability. Even though ASTM C1126 lists two grades and three types, Type III, Grade 1 is the only material designated for use in equipment and piping insulation. The other types are used for roofing and building sheathing. The maximum thermal conductivity at 75 degrees F (24 degrees C) for the Type III, Grade 1 phenolic insulation is 0.13 K (0.0187 Ksi). Applications for phenolic insulation are on equipment, tanks, and piping exposed to freezing temperatures.
Polyolefin (or Polyethylene) insulation is specified in ASTM C1427 as Type I and II. Type I is made up of preformed tubes and Type II is manufactured into sheets. Both “polyolefin” and “polyethylene” are considered synonymous and refer to the same type of material. Polyolefin/polyethylene consists of flexible, closed cell products. The maximum thermal conductivity is 0.35 K (0.05 Ksi) at 75 degrees F (24 degrees C) and the maximum water permeability values are 0.05 perm-inch (0.073 ng/Pa s m). The tubular product is available with and without pre-applied adhesive in ID size range from 3/8 inch (9.5 mm) to 4 inch (102 mm) and in wall thicknesses from 3/8 inch (9.5 mm) to 1 inch (25 mm). The insulation meets the flame spread index of less than 25 and smoke developed index of less than 50. Applications for polyolefin/polyethylene are on piping where the maximum temperature is below 200 F degrees (93 degrees C). These materials are usually installed without additional vapor retarder facings. All seams including termination points need to be sealed with manufacturer recommended contact adhesive. A weatherproof jacket needs to be added to protect against UV and ozone when exposed to the elements.
Accessory materials which are a component of the insulation system are just as important as the insulation material. Simply stated, the insulation system will be compromised if the incorrect accessory material is incorporated. Typical accessory materials include aluminum or stainless steel jacketing, stainless steel bands and screws, acrylic latex and/or hypalon mastic, and electrometric joint sealers. Due to its durability, metal jacketing is suitable for most outdoor applications.
Editing of Section 210716 is designed to start in PART 2, progress to PART 3, and finish up with PART 1.
The various types of fire suppression equipment and equipment piping insulations including accessories comprise the main paragraphs in PART 2. When a particular type of insulation and accessory is activated for use in the project, the appropriate insulation type listed under Equipment and Equipment Piping Insulation under SECTION INCLUDES is activated along with the accessory item(s) listed under Accessories. Related articles and optional text in PARTS 1 and 3 will be activated as well.
When a particular article or paragraph in PART 2 and PART 3 that contains a reference standard is chosen, the corresponding standard cited under REFERENCE STANDARDS in PART 1 is activated. If the Consolidated List of Citations option is active, cross sectional links (not visible in the links window) will activate the reference standard in Section 014219 – Reference Standards as well.
When a particular article or paragraph in PART 2 and PART 3 that cites another section is chosen, the corresponding Section listed under PART 1 – RELATED REQUIREMENTS is activated. Certain Sections listed under PART 1 – RELATED REQUIREMENTS are not cited in either PART 2 or PART 3 but are listed under RELATED REQUIREMENTS because they include items that might be expected to be found within this Section or include action items important for the completion of the work that are not specified in an obvious location (e.g. isn’t obvious from the section title).
All optional text and choices under PART 2 include a fill-in to accommodate any updates that listed manufacturers may offer but are not shown in the choice options. Default options for choices are based upon what would be reasonable for the application. The content of PART 2, including the choices, has been structured to accommodate the listed manufacturers.
An insulation schedule has been provided in PART 3 since piping and equipment insulation schedules are not typically shown on the Drawings.