HT7E, HT6D and HT6C are balanced type pumps of single vane that have fixed displacement. It has been designed for higher operation of pressure and more flow having the same size of housing.
It has a pin-vane design, which applies the outlet pressure continuously on the pin, which provides the light and steady force going against that vane. The bottom and top area of this vane are subjected to similar pressure, either outlet or inlet pressure, depending on location of vane during rotation of rotor. This design minimizes the noise level and also improves efficiency of volume.
The shaft not being with the cartridge, allows easy flow capacity change and also field servicing even without removal of the pump from its own mounting.