Dark metal pipe located on the following requirements of the construction

Dark metal tube construction located on the following requirements : 1. Metal pipe clamp fixed applications , the spacing between the support point should not exceed 3 meters. 0.3 meters away from the junction box office, the card will use the tube pipe fixed . In the elbow where both sides have fixed .
2 cable and cable with pipe laying, shall be within the pre- plastic -tube underground pipe . The cable laying pipe in the child , so that separate cables and cable laying , the outer diameter of the tubes should be 2.5 times the cable diameter . 3 When the weak and the strong electrical conduit pipes laid in parallel , you should try to keep a certain distance between the two to 13CM or so. 4, when the line specified with , the bending radius of not less than 6 times the tube diameter , when only one between two junction boxes is bent, the bending radius of not less than 4 times the pipe diameter . 5 horizontal vertical distribution lines laid out protection tube, its horizontal and vertical mounting tolerance of 1.5% , a total length of Dacron tube diameter deviation should not exceed 1 / 2.6 . Pipe should not be folded flat and cracks , the tube should be no iron and burrs , cutting off the mouth should be smooth, the nozzle should be smooth . 7 thin wire threaded pipe connections must be connected to the pipe threading length joint length of not less than 1/ 2 , should be added to both ends of the pipe joints across the ground wire ( not less than 4 mm2 copper wire ) 8 . concrete floors, walls and brick structures of the various information points concealed junction box and pipe connections shall be forced mother fixation. 9 Concealed inside the junction box with concrete requirements with wet cement paper or plastic foam filled inside , not the outside wrapped with cement . Embedded in the floor, walls inside the pipe , junction boxes should be fixed firmly to prevent displacement.
10 When conduit is connected directly to the device , the device should be laying pipe junction box ; when the pipe is connected indirectly with the device should be added wire protection hose or flexible metal protection tube ( metal hose ) connection ; optional Hydraulic tube fittings shall not use metal hose as grounding .11 galvanized steel or flexible metal wire protection tube jumper ground wire should be grounded using a dedicated line card jumper should not be used welding connection. Ming steel tube should be neat and fixed-point spacing should be uniform , steel pipe card should meet the maximum distance between the specification requirements : Pipe cards and terminals , elbows midpoint , electrical appliances or junction box ( box ) .
12 should be from the edge of 150-500 mm , the middle tube card maximum spacing : thick-walled steel pipe DN15-20 is 1.5 m , thin-walled steel pipe DN15-20 is 1.5 m , ceiling pipe should be laid out inside the pipe requirements of the construction .
13 pipe threading pipe before the water and debris should be cleaned , the wire in the tube may not have Hydraulic hose fittings, joints should be carried out in the terminal box , plastic should be added at the nozzle tip guard , different circuits , different voltage levels, AC and DC conductors shall not penetrate the same root canal .
14 tubing through the building expansion joints , expansion joints at both ends should remain grounded junction box and bolts.