why do the pipes keep splitting on my citroen berlingo?

Someone please help me!!!! I have owned my 1998 citroen berlingo 1.9 diesel van for about 6 years now, but the last 6 months have been a nightmare, the problem started when my van broke down because the fuel pump bearings went, I had this fixed and all was well untill one of the rigid fuel pipes burst, I changed them for some second hand ones but they also split, so I then had some new ones made only for them to now split can anyone please help????