Be taken as the protection ducts when the cables across the special environment like the bridge or river .Especially if FRP cable protection ducts are adopted when the cables the bridges .it is applicable in the following engineering construction areas:
City power grid construction and reconstruction engineering works
reconstruction engineering works
Civil aviation airport engineering construction
Engineering construction of industrial zone and community
Engineering construction of traffic road and bridgeFunctional Characteristics if Product 
    High strength :when it is buried directly under the traffic lane ,the concrete protection layer is not needed,which can speed up the schedule of cable engineering construction .
The materials of pipe are flexible,which can withstand the uter heavy pressure and the damage caused by the foundation settlement .
Insulation,no electric corrosion ,applicable to lay the single core cables;the characteristic of corrosion-resistant allow it to be used in the areas of high temperature and saline-alkai land.
Fire retardant and good perfomance in heating-tesistance;can be used under the high temperature of 130 oC without deforming.
The inner surface is smooth and will not scratch the cable .The ruber rings in the joint ends can adapt to the heat-expansion and cold-contraction and prevent the entry of gravel an mud.

Nominal diameter D	Nominal wall thickness t			Inside diameter D1			The depth of the socket  S	Nominal length L
	DB-N	DB-R	DB-E	DB-N	DB-R	DB-E
50	3	4	5	64	66	68	80	4000-6000
60	3	4	5	74	76	78	80	4000-6000
70	3	4	5	84	86	88	80	4000-6000
80	3	4	5	94	96	98	80	4000-6000
100	3	5	8	116	120	126	80	4000-6000
125	5	6.5	8	145	148	151	100	4000-6000
150	5	8	10	170	176	180	100	4000-6000
175	8	10	12	201	205	209	100	4000-6000