SPARK GAP
(Explosion-proof spark gap with flexible connecting cable）
Potential hazards caused by such an incident in an area classified as “Hazardous” (Division 1) due to the possible presence of an explosive atmosphere, can be avoided by the use of an Explosion-proof Spark Gap type SG4. The spark gap is connected in a parallel across the insulating flange and, since the connection is made using a flexible
Technical Characteristics are as follows:
Response to alternating voltage (50Hz) 1.0kV
Response to surge voltage (1/50s)2.2kV
Surge current rating (8/20s) 100kA
Explosion protection to specification VDE 0171
The spark gap has been certified (No; 111BE-23 805) by the Technical-Physics Federal Institute of Brunswick and issued with a “Design Certificate” (No; B1/477/261/73) by the Bavarian State of Ministry of Public Works.
The Spark Gap may be used in hazardous areas in insulating flanges having an insulation value to 50Hz alternating voltage of greater than 4.4kV.
The complete device consists of:
1)The Spark Gap contained in a housing of die cast zinc to DIN 1743 with cap of MARKALON as protection against accidental bridging.
2)One pair on connecting lugs of hot dipped galvanized mild steel available in three sizes to suit the diameter of the flange bolts.
3)An insulated connecting cable, size 25sq.mm available in three lengths to suit the overall dimensions of the flange joint.
In special cases associated with a high incidence of lightning strikes, as may occur in exposed mountainous regions, or high voltage lines running parallel to pipelines, a special design of SG4 Spark Gap is available with electrodes of tungsten copper, which are highly resistant to burn-off.
