Product Description
In water mains of sizes DN 50 to DN 150, ERHARD Flow Control Valves in straight or angle pattern throttle and control showing excellent results. Globe type ERHARD Control Valves with body of ductile cast iron (SG GGG-50) are equipped with a fixed slotted cylinder of stainless steel. The control piston guided in PTFE lined slide rings moves within this cylinder covering or opening the ports according to the control position required.
The actual valve seat which is an integral part of the slotted cylinder seals by means of an O-ring in a bubbletight manner. Travel is limited by a fixed stop in fully closed position. The slotted cylinder provides for inoffensive energy conversion, minimizing noise and material stress. The control is very much appropriate for long-time operation under cavitation conditions. The piston is connected to the valve stem without end play. All ERHARD Control Valves are equipped with mechanical position indicator as a standard.
ERHARD Control Valves may be equipped with the following interchangeable operating gears:
- Handwheel
- Electric actuator
- Hydraulic or pneumatic actuator
It is always possible to retrofit locally from handwheel to electric actuator valve operation or vice versa without removing the valve from the pipeline. The same applies to replacement of the slotted cylinder including the piston. Due to their sensitive port control, ERHARD Control Valves with handwheel or electric actuator provide starting or stopping of flows causing only very little water hammer, even at the end of long pipelines. Dimensioning of the valves according to the duty involved has to be based on the valve KV parameters considering the differential pressure across the valve and the pipe characteristic curve. For perfect adaptation to the plant, special slotted cylinders can also be used.
For range of sizes DN 100 to DN 1800, see also our datasheet below.
