CABLE GLAND MATERIAL SELECTION

CMP Products offers cable glands, adaptors, reducers and stopper plugs in materials including brass, nickel plated brass, stainless steel, aluminium and non-metallic materials.

Brass cable glands are produced using material grade CuZn39Pb3 (CW614N) to EN12168. Stainless steel cable glands are produced using material grade 316L to BS EN 10088 : Part 3 : 1995.

Using a combination of a variety of different metallic materials and surface finishes in contact with each other CMP has carried out prolonged (500h) Salt Water Spray Tests to ASTM B117 in order to determine the most appropriate cable gland material and / or surface finish treatment that is appropriate for use in extremely hostile salt water marine environments. With the help of MTS Testing Services (http://www.mts.com), who are a NAMAS (UKAS) (http://www.ukas.com) accredited testing body in the United Kingdom, extensive test results have been made available that help to demonstrate the effect of the exposure to the harsh conditions under which the simulated Salt Spray (Salt Fog) Tests are executed.

Below are examples of some of the resultant photographs taken after completion of the tests, which together with the in-depth written test reports and commentaries make very interesting and conclusive reading.

The two brass cables glands pictured above were both in contact with aluminium when subject to the B117 Salt Fog testing regime, but one of these was less susceptible to surface oxidisation and white rust impurities than the other. The outcome of the testing gives positive indicators as to which material surface finish should be selected for cable glands to be used in such conditions.

The Standard Practice for Operating Salt Spray (Fog) Apparatus to B117-02 can be obtained from the ASTM website (http://www.astm.org/Standards/B117.htm).

The following includes a table of suggested cable gland materials to suit the corresponding enclosure and cable armour materials.

Cable Gland Material Selection

With the help of several independently accredited laboratories CMP Products has carried out extensive testing of materials for cable glands to be used in hostile environments, particularly with regards to the mating of dis-similar metals. Together with the results of detailed research and the findings of this bespoke testing, CMP Products has been able to select the most suitable material for cable glands to suit a wide variety of environmental applications including:

• Hostile salt water marine (offshore) situations,
• Dust and salt laden (coastal) atmospheres,
• High and low temperature extremes,
• Ultra Violet (UV) degradation,
• EMI/RFI pollution via electromagnetic interference,
• Metallurgical corrosion caused by chemical attack and liquid,
• Acid and vapourised pollutants, and
• The chemical agents used in industrial cleaning processes such as the wash or hose down operations in the offshore drilling industry.

Recognising that the specific conditions of any installation will play a major part in the selection of the most suitable cable gland material and taking into account the level of environmental exposure along with the nature of the enclosure and cable armour material the following tables are offered as a general guide to operations under normal conditions. Subject to there being no adverse environmental conditions prevailing these tables can be used on a regular basis to determine the cable gland material recommended for several different situations.

CABLE TYPE	ENCLOSURE / CABLE PLATE MATERIAL
	ALUMINIUM	BRASS	STAINLESS STEEL
NON-ARMOURED CABLES	SUGGESTED CABLE GLAND MATERIAL
E.G. PVC/XLPE	ALUMINIUM OR STAINLESS STEEL	BRASS (*)	STAINLESS STEEL OR BRASS (*)
ARMOURED CABLES	SUGGESTED CABLE GLAND MATERIAL
AWA OR ASA	ALUMINIUM OR STAINLESS STEEL	STAINLESS STEEL OR NICKEL PLATED BRASS	STAINLESS STEEL OR NICKEL PLATED BRASS
GSWA, SWA, OR STA	STAINLESS STEEL OR NICKEL PLATED BRASS	BRASS (*)	STAINLESS STEEL OR BRASS (*)
SWB OR GSWB	STAINLESS STEEL OR NICKEL PLATED BRASS	BRASS (*)	STAINLESS STEEL OR BRASS (*)
TCWB	STAINLESS STEEL OR NICKEL PLATED BRASS	BRASS (*)	STAINLESS STEEL OR BRASS (*)
BWB	STAINLESS STEEL OR NICKEL PLATED BRASS	BRASS (*)	STAINLESS STEEL OR BRASS (*)

CABLE TYPE	ENCLOSURE / CABLE PLATE MATERIAL
	STEEL	NON-METALLIC
NON-ARMOURED CABLES	SUGGESTED CABLE GLAND MATERIAL
E.G. PVC/XLPE	BRASS (*) OR STAINLESS STEEL	BRASS (*) OR NON-METALLIC
ARMOURED CABLES	SUGGESTED CABLE GLAND MATERIAL
AWA OR ASA	STAINLESS STEEL OR NICKEL PLATED BRASS	STAINLESS STEEL OR ALUMINIUM
GSWA, SWA, OR STA	BRASS (*) OR STAINLESS STEEL	BRASS (*)
SWB OR GSWB	BRASS (*) OR STAINLESS STEEL	BRASS (*)
TCWB	BRASS (*) OR STAINLESS STEEL	BRASS (*)
BWB	BRASS (*) OR STAINLESS STEEL	BRASS (*)

Note : Where tables make reference to N/P Brass, the definition is Nickel Plated Brass. Where suggested cable gland material is Brass (*), the user may also use optional Nickel Plated Brass Cable Glands at their discretion.

For further information please contact your nearest CMP office location.