in fig3 is enclosed in the valve house 11 in fig2 and rotated 90 u00b0 around its length axis in such a way that the connection pipe 12 is connected with the connection pipe 15 the connection pipe 13 will be connected with the connection pipe 14 thus the change of the direction of the fluid which is the purpose of the invention is achieved on one of the end plates there is a control device 22 which appears from the fig4 and 6 with the help of the control device the valve body can be rotated 90 u00b0 from a normal position to the back flushing position and vice versa the rotational motion of the control device is transferred to the valve body through a shaft 23 different types of control devices can be used pneumatic hydraulic and electric the back flushing valve does not necessarily need to have a control device but may also be rotated manually fig5 and 6 show the two end plates 7 and 8 with the respective connection ports 12 a and 13 a and 14 a and 15 a respectively through which the fluid flows to and from the valve house from fig7 8 and 9 the construction of the back flushing valve is evident in greater detail in the valve house the valve body 16 is shown with the flow passages 17 and 18 which are limited by the two straight pipes 24 and 25 respectively the pipes.