ROCKWOOL insulation for industrial use, wire mesh blanket type, ProRox WM model

ProRox WM

ProRox WM insulation is part of the ProRox series designed for industrial applications, specifically for insulating large heat pipes. ROCKWOOL recommends using it for pipes 14 inches (356 mm) and larger for easy installation. ProRox WM can withstand temperatures up to 650°C, similar to the ProRox PS pipe section type.

Thermal conductivity

Wire mesh blanket insulation can withstand temperatures up to 650-750°C and is certified to ASTM C111 and ASTM C447 standards.

It has also been tested for thermal conductivity according to ASTM C117 standard, which measures thermal conductivity within wire mesh blanket insulation. The results are shown in this table:

Thermal conductivity of ProRox WM

Fire classification and reaction to fire

Due to its melting point above 1,000°C, we tested the insulation for fire classification according to EN13501-1 standard, which categorizes materials from A1 to F based on fire behavior.

Table classifying materials by fire severity

Definition	Classification according to European Standard EN 13501-1
Non-Combustible materials	A1
	A2 – s1d0	A2 – s1d1	A2 – s1d2
	A2 – s2d0	A2 – s2d1	A2 – s2d2
	A2 – s3d0	A2 – s3d1	A2 – s3d2
Combustible materials – very limited contribution to fire	B – s1d0	B – s1d1	B – s1d2
	B – s2d0	B – s2d1	B – s2d2
	B – s3d0	B – s3d1	B – s3d2
Combustible materials – limited contribution to fire	C – s1d0	C – s1d1	C – s1d2
	C- s2d0	C – s2d1	C – s2d2
	C – s3d0	C – s3d1	C – s3d2
Combustible materials – medium contribution to fire	D – s1d0	D – s1d1	D – s1d2
	D – s2d0	D – s2d1	D – s2d2
	D – s3d0	D – s3d1	D- s3d2
Combustible materials – highly contribution to fire	E	E – d2
Combustible materials – easily flammable	F

“s” Smoke emission level: ranges from 1 (low-no smoke) to 3 (high smoke emission)

“d” Flaming droplets: ranges from 0 (no droplets) to 1 (many droplets)

Table showing levels of smoke production and flaming droplets

Additional class			Level Definition
Smoke emission during combustion	S	1	Quantity/speed emission of absent or weak
		2	Quantity/speed emission of average intensity
		3	Quantity/speed emission of high intensity
Production of flaming droplets/particles during combustion	D	0	No dripping
		1	Slow dripping
		2	High dripping

From the material classification table, we can see that ProRox WM insulation is classified as A1, which is non-combustible, produces no smoke, and no flaming droplets. Therefore, it can be confidently used for fire prevention.

Chloride testing

In hot water pipe insulation, a common problem is rust that corrodes the pipe surface and interior. This is often undetectable until the jacket and thermal insulation are removed, by which time significant damage requiring costly pipe replacement may have occurred.

Rust is caused by moisture from water vapor, oxygen, and catalysts like chloride and fluoride, forming brown rust deposits on the pipe surface.

We can prevent rust formation in several ways, including cleaning the pipe surface before applying protective coating and maintaining the jacket integrity by not stepping on it.

The ProRox series of insulation reduces the use of chloride water in production, lowering chloride content in the insulation. We tested our insulation according to ASTM C871 standard, which measures chloride, fluoride, silicate, and sodium ion content in thermal insulation to assess potential pipe material damage. Our test results showed only 10 ppm of chloride in the insulation, which is very low and has negligible impact on rust formation.

Moisture and water vapor

Moisture and water vapor accumulation in insulation is another cause of pipe surface rust. Vapor and moisture can come from two sources: inside the pipe (leaks) or outside the jacket. Using ROCKWOOL insulation with an open-cell structure allows easier evaporation of water vapor and droplets compared to closed-cell insulation.

Additionally, ROCKWOOL insulation is treated with silicone water repellent during production, making every fiber water-resistant. If water droplets fall on the insulation, they will bead up, or if water is poured on the insulation, it will flow over the surface like on a car windshield.

We also tested the mineral wool insulation according to ASTM C1104/C1104M standard to determine its water absorption. The test results showed that the mineral wool insulation absorbs only 1% of its weight in water.

Mineral wool insulation causing cancer

Only in Thailand is there concern about “mineral wool” causing “cancer”. This is a misunderstanding due to translation issues. Mineral wool insulation (ROCKWOOL) and asbestos are confused due to similar terminology. We will explain the difference.

Asbestos is a naturally occurring group of minerals with white fibers smaller than 0.1 micron, derived from silicate minerals. It can become airborne and break into smaller, sharp fibers. It is a known carcinogen.

ROCKWOOL mineral wool insulation is produced through a controlled manufacturing process that melts basalt and dolomite rocks to spin fibers 4-6 microns in size. These fibers can break but have large, rounded ends too big to enter the lungs. It does not cause cancer.

Table of differences between ROCKWOOL mineral wool insulation and asbestos

Difference	ROCKWOOL mineral wool insulation	Asbestos
Raw material	Basalt rock, dolomite	Silicate mineral group
Source	Standardized machinery	Accumulation of silicate minerals
Fiber characteristics	4-6 microns, rounded fiber ends	Smaller than 1 micron, sharp fiber ends
Health impact	Does not cause cancer in humans	Causes cancer in humans
Classification by International Agency for Research on Cancer	Group 3: Not classifiable as to its carcinogenicity to humans	Group 1: Carcinogenic to humans

We can find information about carcinogenic substances from the International Agency for Research on Cancer (IARC). IARC classifies products into 3 groups:

Table classifying carcinogenic substances

Group 1	Carcinogenic to humans
Group 2A	Probably carcinogenic to humans
Group 2B	Possibly carcinogenic to humans
Group 3	Not classifiable as to its carcinogenicity to humans