Thanks =) I created the "pipe entity" like this:
https://github.com/Terasology/Rails/blob/master/assets/prefabs/pipe.prefab
"Pipe entity" is minecart's child.
{
"Location" : {
},
"blockParticleEffect" : {
"spawnCount" : 0,
"initialVelocityRange" : [0, 0, 0]...