Standard BS 476 Test Contents

BS476-3:2004 external fire exposure roof test

BS476-4:1970 Non-combustibility test for materials

BS476-5:1979 Method of test of ignitability

BS476-6:1989 Method of test for propagation for materials

BS476-7:1997 Surface spread of flame test for material

BS476-11:1982 Method for assessing the heat emission from building materials

BS476-12:1991 Ignitability of products by direct flame impingement

BS476-15:1992 Method for measuring heat release of products-cone calorimeter

BS476-20:1987 Method for determination of the fire resistance of elements of construction (general principles)

BS476-21:1987 Methods for determination of the fire resistance of loadbearing elements of construction ­2U

BS476-22:1987 Methods for determination of the fire resistance of non-loadbearing elements of construction

How to distinguish Fire resistant and Flame retardant

Resistant in this context is defined as a material that is inherently resistant to catching fire (self-extinguishing) and does not melt or drip when exposed directly to extreme heat.

Retardant is defined as a material that has been chemically treated to self-extinguish.

Fire resistant cable is cable which will continue to operate normally in the presence of prolonged fire for a specified time under defined conditions. Fire resistance cable shall pass test as per IEC 60331.

Flame retardant cable are not rated to continue to operate under fire circumstance but it will resist the propagate of fire into a new area by having behavior in fire under defined conditions which is proven by passing the test as per IEC 60332.

Fire resistant cable is applied to critical circuit which operates on energized to trip or energized to operate and circuit which needs to still operate during fire.

Flame retardant cable is applied to circuit other than mention above. It serve for instrument loop which operates in fail safe mode.

In term of cable construction, it is essential to distinguish the outer sheath colour between flame retardant cable and fire resistant cable. Commonly, fire resistant cable has red outer sheath/jacket while flame retardant may have grey or black outer sheath/jacket.

Flame-retardant polyester and polyamide textiles

Polymeric materials are a large and growing fraction of the fire load in homes, in commercial environments, and in transportation, and are inherently flammable. Organic polymers degrade to give volatile combustible materials when they are heated above certain critical temperatures, which in turn depend on their chemical structures. Successful strategies to reduce flammability of a polymeric material involve interrupting the complex stages of the combustion process at one or more points so as to reduce the rate and/or change the mechanism of combustion at that point. The additives and reactives can interrupt the burning cycle of a polymer in several ways: by altering the thermal decomposition mechanism of a polymer; by quenching the flame; or by reducing the heat transferred from the flame to the decomposing polymer. It is a common practice, especially from a commercial point of view, to use a combination of flame retardants for polymeric materials. In many cases, these flame-retardant mixtures can give an enhanced performance at low cost. An alternative type of flame-retardant surface treatment for fibers and fabrics is the intumescent coating, applied using conventional coatings technology. 

What is glow wire testing machine?

This machine is according to IEC60695 "glowing filament test method"to design and produce. requirements applicable to electrical and electronic products, household appliances and materials fire hazard testing, simulate burning elements or overload resistance and the like heat or ignition source thermal stress caused by a short time.

Glow wire tester adopts chamber part and control part integrated design, convenient installation and debugging. Test chamber shell and important parts of stainless steel manufacturing, smoke, gas corrosion resistance; Automatic regulation control system adopts thyristor current, achieve the purpose of precise control temperature; Time, temperature digital display, easy observation records, stable and reliable use.